TW201517074A - Manufacturing method of arc shaped magnet and product and extrusion die thereof - Google Patents

Abstract

A manufacturing method of arc shaped magnet is presented; to solve the problem that prior arc shaped magnet doesn't have radial magnetic lines of force. This manufacturing method comprises following steps: make a Nd-Fe-B permanent magnetism material inside a extrusion die stays in a working temperature and present with a plastic state; extrude the Nd-Fe-B permanent magnetism material to make it come to plastic deformation, and make the Nd-Fe-B permanent magnetism material pass through at least one arc shaped passage of the extrusion die with a velocity of 0.005~0.5 mm/sec, then get at least one solid arc shaped arc shaped magnet after cooling. Products of the manufacturing method and the extrusion die use in the manufacturing method are also disclosed.

Description

Method for manufacturing curved magnetic member, finished product and extrusion die

The present invention relates to a method of manufacturing a magnetic member, and more particularly to a method of manufacturing a curved magnetic member having radial magnetic lines of force, and a finished product and an extrusion die.

In general, the conventional motor generally includes a base, a stator and a rotor. The base is provided with a shaft tube, and the stator is coupled to the outside of the shaft tube. The rotor has a hub, a rotating shaft and a magnetic pole. The shaft is coupled to the center of the hub and rotatably inserted into the shaft tube of the base. The magnetic member is coupled to a predetermined portion of the hub and forms an air gap with the stator to When the stator generates an alternating magnetic field, the rotor is rotated by the magnetic member.

Among them, the above-mentioned magnetic member is usually selected to have an outer shape of an arc shape so as to be coupled with the hub portion of the rotor. On the other hand, under the trend of gradually thinning and thinning electronic products, the selection of the above-mentioned magnetic parts by using a rare earth permanent magnet material having a high magnetic energy product also helps to reduce the volume of the motor, but can maintain or even enhance the motor. The rare earth permanent magnet material generally comprises a neodymium iron boron permanent magnet material and a rare earth cobalt permanent magnet material, and the current formation of the rare earth permanent magnet material is mostly transmitted through high temperature sintering. Therefore, referring to Fig. 1, when the curved magnetic member 9' is to be made of a rare earth permanent magnet material, the current manufacturing method is to first sinter the rare earth permanent magnet material into a large square magnetic member 9, and then cut and grind it. The desired shape is formed to shape the curved magnetic member 9'. However, the manufacturing method of sintering, cutting, and grinding first requires removal of a large amount of materials, which is not only a waste of raw materials, but also has many manufacturing steps, and thus has problems such as high manufacturing cost and poor manufacturing efficiency.

In addition, please refer to Figure 2 at the same time, because the square magnet is formed by sintering. When the material is 9, the magnetic powder is induced to be aligned in a specific direction by an external strong magnetic field, and most of the magnetic lines M are arranged in parallel or perpendicular to a predetermined direction, so that the curved magnetic shape is cut into a circular arc shape. In the case of the piece 9', the magnetic lines M are arranged in parallel, so that the curved magnetic member 9' has a magnetic force at the central portion of the crucible higher than that of the edge portion, so the curved magnetic member 9' is used in the motor. In the rotor, the arc-shaped magnetic member 9' whose magnetic force is uneven will cause a problem that the motor does not run smoothly, thereby generating abnormal sound and shortening the service life of the motor.

In addition, the rare earth permanent magnet material needs to be additionally added with yttrium element (Dy) in order to make the sintered magnetic member have high temperature resistance characteristics, so that the magnetic member can be applied to a wide range of working temperatures, so that the magnetic member The working environment to be applied subsequently is not limited; however, in recent years, there has been a trend of rising prices, so adding 镝遂 becomes one of the burdens of manufacturing costs.

For the above reasons, the manufacturing method of the conventional curved magnetic member is still necessary for improvement.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method of manufacturing a curved magnetic member which can be formed into a curved magnetic member having radial magnetic lines of force such that the curved magnetic member has a uniform magnetic force.

A second object of the present invention is to provide a method of manufacturing a curved magnetic member which can reduce wasted raw materials and reduce manufacturing costs.

Another object of the present invention is to provide a method of manufacturing a curved magnetic member that simplifies the process steps to improve manufacturing efficiency.

Still another object of the present invention is to provide a method of manufacturing a curved magnetic member which can be made to have a high temperature resistance characteristic without adding niobium.

In order to achieve the foregoing object, the technical content of the present invention includes: a method for manufacturing a curved magnetic member, comprising: maintaining a neodymium-boron permanent magnet material placed in an extrusion die at a working temperature to cause the crucible The iron-boron permanent magnet material is in a plastic state; the neodymium-iron-boron permanent magnet material extruded in a plastic state causes plastic deformation of the neodymium-iron-boron permanent magnet material. And extruding from at least one curved passage provided at one end of the extrusion die at a speed of 0.005 to 0.5 mm/sec, and cooling at the time of extrusion to obtain at least one curved magnetic member of a fixed shape.

Wherein, the extrusion die can be heated by a heating device to raise the temperature of the NdFeB permanent magnet material in the extrusion die to the above operating temperature; the operating temperature is about 0.6 of the melting point of the NdFeB permanent magnet material. ~0.9 times, for example 680~1000 °C.

An extrusion die for implementing the above-mentioned manufacturing method of a curved magnetic member, wherein the number of arcuate passages provided at one end of the extrusion die is a single one, and the arcuate passage has an opposite inner arc surface and an outer portion The arc surface, the inner arc surface and the outer arc surface of the arc channel are concentrically arranged.

An extrusion die for implementing the above-mentioned manufacturing method of the curved magnetic member, wherein the number of arcuate passages provided at one end of the extrusion die may be several, each of the arcuate passages having a relatively inner arc surface and a The outer arc surface, the inner arc surface and the outer arc surface of each of the arc channels are concentrically arranged. Moreover, the plurality of curved passages may be arranged in a ring shape, and the inner arc surfaces of the arcuate passages are disposed concentrically, and the shortest distances from the inner arc surfaces to the axial center are the same, and the outer curved surfaces are the same The shortest distance of the axis is the same.

An arc-shaped magnetic member extruded from the above-mentioned manufacturing method of a curved magnetic member, the curved magnetic member exhibiting a shape matching the curved passage of the extrusion die, the curved magnetic member having an opposite one The inner arc surface and the outer arc surface, the magnetic lines of force after the magnetization of the curved magnetic member are radially distributed between the inner arc surface and the outer arc surface.

Wherein, the magnetic lines of force after the magnetization of the curved magnetic member can almost form a shape orthogonally passing through the inner arc surface and the outer arc surface.

Wherein, the magnetic energy product after magnetization of the curved magnetic member can reach 30~40 MGOe.

Accordingly, the method for manufacturing the curved magnetic member of the present invention can be formed into a curved magnetic member having radial magnetic lines, so that the curved magnetic member has a uniform magnetic force, and at the same time, waste material is reduced and the process steps are simplified. Reduce manufacturing costs and improve manufacturing efficiency.

In addition, the manufacturing method of the curved magnetic member of the present invention can be modified by extrusion Since the internal crystal grains of the variable material are arranged, the magnetic member can be made to have high temperature resistance without adding strontium to the molten NdFeB permanent magnet material, which can further reduce the manufacturing cost.

〔this invention〕

1‧‧‧Extrusion mould

11‧‧‧Ontology

111‧‧ ‧ room

12‧‧‧Mold head

121‧‧‧ curved channel

122‧‧‧Inside curved surface

123‧‧‧Outer curved surface

13‧‧‧Extrusion

131‧‧‧Squeeze pad

2‧‧‧NdFeB permanent magnet material

2'‧‧‧ curved magnetic parts

21‧‧‧Inside curved surface

22‧‧‧Outer curved surface

3‧‧‧ heating device

M‧‧‧ magnetic lines

[study]

9‧‧‧Magnetic parts

9'‧‧‧ curved magnetic parts

M‧‧‧ magnetic lines

Fig. 1 is a schematic view showing a manufacturing method of a conventional curved magnetic member.

Fig. 2 is a schematic view showing the distribution of magnetic lines of a curved magnetic member made by a sintering method.

Fig. 3 is a schematic view showing the structure of an extrusion die used in the method for manufacturing a curved magnetic member of the present invention (1).

Fig. 4 is a schematic view showing the implementation of the method for producing a curved magnetic member of the present invention (1).

Fig. 5 is a schematic view showing the implementation of the method for producing a curved magnetic member of the present invention (2).

Fig. 6 is a schematic view showing the implementation of the method for producing a curved magnetic member of the present invention (3).

Fig. 7 is a view showing the distribution of magnetic lines of force of the curved magnetic member extruded by the manufacturing method of the curved magnetic member of the present invention.

Fig. 8 is a schematic view showing the structure of an extrusion die used in the method for manufacturing a curved magnetic member of the present invention (2).

The above and other objects, features and advantages of the present invention will become more <RTIgt; In a preferred embodiment of the method, the arc-shaped magnetic member is formed mainly by the squeezing method, and the arc-shaped magnetic member can have a magnetic flux extending radially after being magnetized.

Please refer to FIG. 3, which is an extrusion die used in the manufacturing method of the curved magnetic member of the present invention; in the embodiment, the extrusion die 1 may include a body 11, a die head 12 and an extrusion. The inside of the body 11 is provided with a chamber 111 for accommodating the NdFeB permanent magnet material 2. The die head 12 is provided with at least one through-circular curved passage 121, and the die head 12 is coupled to One end of the body 11 is configured to communicate the at least one arcuate passage 121 with the chamber 111; wherein the arcuate passage 121 has an opposite inner arc surface 122 and an outer arc surface 123, the arcuate passage 121 The inner arc surface 122 and the outer arc surface 123 are preferably disposed concentrically. Moreover, in other embodiments, the die head 12 may also be integrally formed with the body 11, and the invention is not limited thereto. The extrusion member 13 is axially displaceably disposed in the chamber 111 of the extrusion die 1; preferably, the extrusion member 13 is further provided with a pressing pad 131 toward one end of the arcuate passage 121.

Referring to FIGS. 4-6, the manufacturing method of the curved magnetic member according to the present invention comprises the steps of: maintaining the neodymium-boron permanent magnet material 2 placed in the extrusion die 1 at one. The working temperature causes the neodymium iron boron permanent magnet material 2 to be in a plastic state. In particular, in the operating temperature, the Nd-rich phase of the NdFeB permanent magnet material 2 is in a molten state. Contribute to the implementation of the method; continue to squeeze the NdFeB permanent magnet material 2 maintained at the working temperature, plastically deform the NdFeB permanent magnet material 2, and set the speed at 0.005~0.5mm/sec. At least one curved passage 121 at one end of the extrusion die 1 is extruded and cooled at the time of extrusion to obtain at least one curved magnetic member 2' having a fixed shape.

More specifically, in implementation, the NdFeB permanent magnet material 2 may be preheated to the above-mentioned working temperature, and the NdFeB permanent magnet material 2 exhibiting a plastic state may be placed in the body 11 of the extrusion die 1. Alternatively, as shown in FIG. 4, the NdFeB permanent magnet material 2 may be placed in the chamber 111 of the body 11 of the extrusion die 1, as shown in FIG. The extrusion die 1 is heated by a heating device 3, so that the neodymium-boron-boron permanent magnet material 2 located in the chamber 111 can be heated to the above-mentioned operating temperature to assume a plastic state. Wherein, before the heating, the NdFeB permanent magnet material 2 may be an ingot or in a powder form. In addition, the working temperature may be selected from 0.6 to 0.9 times the melting point of the NdFeB permanent magnet material 2 (ie, the working temperature = (0.6 to 0.9) × the melting point of the NdFeB permanent magnet material 2); for example, The melting point of the NdFeB permanent magnet material 2 is about 1150 ° C, so the above working temperature is about 680 ~ 1000 ° C; if the working temperature is lower than 680 ° C, the formed curved magnetic member 2' will be easily broken, If the working temperature is higher than 1000 ° C, the NdFeB permanent magnet material 2 Then, the phenomenon of grain growth of the internal microstructure may be caused by the high temperature, thereby affecting the distribution of the magnetic lines of force of the subsequently extruded curved magnetic member 2'.

Referring to FIG. 6, after the neodymium iron boron permanent magnet material 2 located in the chamber 111 is heated to a preset operating temperature to exhibit red hot and plastic state, the extrusion of the extrusion die 1 can be actuated. Pressing member 13 and controlling the axial displacement speed of the pressing member 13 in the chamber 111 to uniformly press the NdFeB permanent magnet material 2 in a plastic state by the pressing pad 131 at the end of the pressing member 13 The NdFeB permanent magnet material 2 is extruded through the curved passage 121 and cooled to room temperature during extrusion to obtain a curved magnetic member 2' having a fixed shape and not deformable; this embodiment The temperature can be naturally cooled by the temperature of the external environment, but it is not limited thereto. For example, the working fluid (such as inert gas, air, oil, water, etc.) can be selected to pass through the heat convection. The iron-boron permanent magnet material 2 is cooled. Wherein, the speed at which the NdFeB permanent magnet material 2 is extruded from the curved passage 121 is preferably 0.005 to 0.5 mm/sec; when the speed is lower than 0.005 mm/sec, the NdFeB permanent magnet material 2 is at an operating temperature. If the time is too long, the grain of the microstructure will be coarse, which will affect the magnetic properties of the extruded magnetic member 2'. When the speed is higher than 0.5 mm/sec, the NdFeB permanent magnet material 2 is in the unit. The amount of deformation due to local plasticity during the time is too large, which may cause cracking of the extruded curved magnetic member 2'. Moreover, the NdFeB permanent magnet material 2 extruded in a plastic state by the pressing pad 131 allows the NdFeB permanent magnet material 2 to be uniformly displaced, thereby avoiding indentation on the surface of the NdFeB permanent magnet material 2. Or cracks.

Referring to FIG. 7, according to the foregoing steps, the extruded arc-shaped magnetic member 2' exhibits a shape matching the curved passage 121 of the extrusion die 1, thereby having a corresponding inner curved surface 21 and An outer curved surface 22; wherein the neodymium iron boron permanent magnet material 2 in a plastic state is superplastically formed when pressed at a predetermined speed, and the flow of the neodymium iron boron permanent magnet material 2 is restricted by the curved passage 121 The direction and the deformation amount of each portion of the NdFeB permanent magnet material 2, so that when the NdFeB permanent magnet material 2 is pressed and passed through the curved passage 121, the NdFeB permanent magnet material 2 is internally microscopically The tissue changes its arrangement of internal crystal grains due to plastic deformation, forming material anisotropy. After the magnetized magnetic member 2' is magnetized, the magnetic lines of force M radially distributed between the inner curved surface 21 and the outer curved surface 22 can be formed relatively easily; that is, the curved magnetic member The magnetic field line M after 2' magnetization can almost always show the shape of the inner arc surface and the outer arc surface. Therefore, the extruded arc-shaped magnetic member 2' can have a magnetic average characteristic, and the magnetic force of the central portion is higher than that of the edge portion, so that the extruded curved magnetic member 2 is formed. When the rotor of the motor is used, the magnetic flux M of the curved magnetic member 2' can be radially arranged around the rotating shaft of the rotor, so that the rotor can rotate the rotor by the alternating magnetic field generated by the stator. It ensures that the motor can run smoothly and reduce the abnormal sound. It can be applied to high-efficiency motors and has the effect of extending the service life of the motor.

Moreover, since the curved magnetic member 2' extruded from the curved passage 121 is the final shape when it is used, it is necessary to cut and grind from the square-shaped magnetic member as compared with the sintering. By processing into a desired shape, the manufacturing method of the curved magnetic member of the present invention can eliminate the cutting step, not only can improve the manufacturing efficiency, but also can greatly improve the material utilization rate, reduce the waste generated to save the material cost, and thereby effectively reduce the overall manufacturing. cost. In addition, according to experiments, the curved magnetic member 2' extruded into the shape of the curved magnetic member of the present invention has a magnetic energy product of 30 to 40 MGOe after magnetization, which is no less than the sintered magnetic member. Therefore, the extruded arc-shaped magnetic member 2' does have good magnetic properties.

In addition, since the present invention forms the curved magnetic member 2' by extrusion, during the extrusion process, the NdFeB permanent magnet material 2 maintained in the preset operating temperature range can be plastically deformed to change the material. The arrangement of the internal crystal grains, so that even if the crucible is not added to the NdFeB permanent magnet material 2, the arc-shaped magnetic member 2' which is extruded can still have the characteristics of high temperature resistance, so that the curved magnetic member 2' is subsequently The working environment of the application is relatively limited, and at the same time has the effect of reducing manufacturing costs.

It is worth mentioning that, referring to Fig. 8, when the number of arcuate passages 121 provided at one end of the extrusion die 1 is selected to be several (for example, four), the corresponding number can be extruded at one time. The arc-shaped magnetic member 2' can improve the material properties of the plurality of curved magnetic members 2' in addition to improving the yield; in the embodiment, the number of the ones at the end of the extrusion die 1 The arcuate passages 121 may be arranged in an annular shape, and the inner curved surfaces 122 of the curved passages 121 may be disposed coaxially, and the shortest distances of the inner curved surfaces 122 to the axial center are preferably the same; each of the arcs The outer curved surface 123 of the shaped passage 121 is also the same.

According to this, a plurality of curved magnetic members 2' which are assembled in a rotor for the same motor can be synchronously manufactured at one time, and a plurality of curved magnetic members 2' having almost the same material properties can be formed by the same forming conditions. And the magnetic lines of force of the plurality of curved magnetic members 2' can be uniformly arranged radially around the same axis; thus, if the plurality of curved magnetic members 2' are assembled to the rotor of the same motor, Effectively avoiding any slight difference in material properties, resulting in uneven operation of the motor, and further improving the performance of the motor.

In summary, the method for manufacturing the curved magnetic member of the present invention can be formed into a curved magnetic member having a radial magnetic field line, so that the curved magnetic member has a uniform magnetic force.

The manufacturing method of the curved magnetic member of the invention can directly extrude the final shape when the curved magnetic member is used, and different from the prior art, the magnetic member of the large volume needs to be firstly formed, and then the large-volume magnetic member can be further removed from the large-volume magnetic member. The magnetic component of the desired shape is cut out, and the invention can greatly improve the utilization rate of the material, reduce the waste generated to save the material cost, and thereby effectively reduce the overall manufacturing cost.

The manufacturing method of the curved magnetic member of the invention can directly extrude the final shape when the curved magnetic member is used, so that the processing step of cutting the desired shape from the square magnetic member can be eliminated, and the process step can be simplified. To improve manufacturing efficiency.

The manufacturing method of the curved magnetic member of the present invention can change the arrangement of the inner crystal grains of the material by extrusion, so the present invention does not need to add yttrium to the NdFeB permanent magnet material to make the fabricated magnetic member have High temperature resistance helps to further reduce manufacturing costs.

Although the present invention has been disclosed by the above-described preferred embodiments, it is not intended to limit the invention, and it is apparent to those skilled in the art without departing from the spirit and scope of the invention. The various modifications and variations of the embodiments are still within the technical scope of the invention. The scope of the invention is defined by the scope of the appended claims.

2'‧‧‧ curved magnetic parts

21‧‧‧Inside curved surface

22‧‧‧Outer curved surface

M‧‧‧ magnetic lines

Claims (10)

A method for manufacturing a curved magnetic member, comprising: maintaining a neodymium iron boron permanent magnet material placed in an extrusion die at a working temperature, so that the neodymium iron boron permanent magnet material is in a plastic state; and the extrusion is in a plastic state. The NdFeB permanent magnet material plastically deforms the NdFeB permanent magnet material and extrudes from at least one curved passage provided at one end of the extrusion die at a speed of 0.005 to 0.5 mm/sec. The cooling is performed to obtain at least one curved magnetic member in a fixed shape. The method for manufacturing a curved magnetic member according to claim 1, wherein the extrusion die is heated by a heating device to raise the temperature of the NdFeB permanent magnet material in the extrusion die to the above operating temperature. . The method for manufacturing a curved magnetic member according to claim 1, wherein the operating temperature is 0.6 to 0.9 times the melting point of the neodymium iron boron permanent magnet material. The method for manufacturing a curved magnetic member according to claim 1, wherein the operating temperature is 680 to 1000 °C. An extrusion die for carrying out the manufacturing method of the curved magnetic member according to claim 1, wherein the number of the arcuate passages provided at one end of the extrusion die is a single one, and the curved passages have opposite An inner arc surface and an outer arc surface, the inner arc surface and the outer arc surface of the arc channel are concentrically arranged. An extrusion die for carrying out the manufacturing method of the curved magnetic member according to claim 1, wherein the number of arcuate passages provided at one end of the extrusion die is several, and each of the curved passages has a relative An inner arc surface and an outer arc surface, wherein the inner arc surface and the outer arc surface of each arc channel are concentrically arranged. The extrusion die of claim 6, wherein the plurality of arcuate passages are arranged in a ring shape, and the inner arc faces of the arcuate passages are concentrically arranged, and each of the inner arc faces is The shortest distance of the axis is the same, and the shortest distance from the outer arc surface to the axis is the same. An arc-shaped magnetic member extruded from a method for manufacturing a curved magnetic member according to claim 1, wherein the curved magnetic member exhibits a shape matching the curved passage of the extrusion die, the arc The magnetic member has a relatively inner arc surface and an outer arc surface, and the magnetic flux after the magnetization of the curved magnetic member is radially distributed between the inner arc surface and the outer arc surface. The curved magnetic member according to claim 8, wherein the magnetic line after magnetization of the curved magnetic member is in a form of orthogonally passing through the inner arc surface and the outer arc surface. The curved magnetic member according to claim 8, wherein the magnetic product of the curved magnetic member after magnetization is 30 to 40 MGOe.