Patent Application
20200030881
The present invention relates to a magnet, and more particularly, to a method of manufacturing a magnet capable of using only a single pole.
Magnets capable of using only a single pole are generally referred to as shielding magnets. These shielding magnets are devices, which are inserted into a case of a portable electronic device to be in contact with a hall integrated circuit (IC) of the portable electronic device so as to operate and brake the portable electronic device.
Related arts of shielding magnets include Korean Patent Laid-open Publication No. 10-2014-0112764 (published on Sep. 24, 2014, entitled as “Electronic apparatus having protection case and method of operating the same”) and Korean Utility-model Registration No. 20-0470862 (registered on Jan. 8, 2014, entitled as “Mobile phone case having a shielding magnet for driving a hall IC).
The above-descried shielding magnet includes a permanent magnet and a yoke coupled to the permanent magnet, as disclosed in Korean Utility-model Registration No. 20-0470862. In such a shielding magnet, compared to specific surface Gauss of the permanent magnet, magnetic shielding of 20% to 96% occurs in a sealed pole via the yoke, and an enforced magnetic force of 105% to 180% occurs in an opened pole that does not interfere with the yoke.
However, in the conventional shielding magnet, the permanent magnet and the yoke are bonded to each other and combined with (joined to) each other via an adhesive, such as a glue. Thus, when an adhesion of the glue is deteriorated, the permanent magnet and the yoke are separated from each other. Also, because the bonding work of the permanent magnet and the yoke is manually performed, labor costs increase, and a long working time is required, which results in an increase in a unit price of a product.
The present invention provides a method of manufacturing a magnet capable of using only a single pole, whereby a combination force between a permanent (or referred to as a magnet) and a yoke (or referred to as a shielding metal) can be improved without performing a manual bonding work therebetween and then the efficiency of subsequent processes, such as polishing and plating, after combination and completeness of a product can be improved.
According to an aspect of the present invention, there is provided a method of manufacturing a magnet capable of using only a single pole, the method including: (a) forming a green compact having an oriented powder by magnetically pressing an alloy powder for manufacturing a magnet; (b) placing an iron-related metal powder for manufacturing a shielding metal so that at least one surface of the green compact is exposed and the remaining surfaces of the green compact are surrounded; (c) forming a compression molded body by mechanically pressing a resultant structure of (b); and (d) forming a sintered body by sintering the compression molded body.
According to another aspect of the present invention, there is provided a method of manufacturing a magnet capable of using only a single pole, the method including: (a) putting an iron-related metal powder for manufacturing a shielding metal into a predetermined mold; (b) forming a metal powder green compact having a groove with a predetermined size in a center of one surface thereof by mechanically pressing the iron-related metal powder; (c) forming an incompletely-sintered body having the groove by incompletely sintering the metal powder green compact; (d) forming an alloy powder green compact having an oriented powder to correspond to a shape of the groove by magnetically pressing the alloy powder for manufacturing a magnet; (e) inserting the alloy powder green compact into the groove of the incompletely-sintered body; and (f) forming a completely-sintered body by completely sintering a resultant structure of (e).
According to another aspect of the present invention, there is provided a method of manufacturing a magnet capable of using only a single pole, the method including: (a) putting an iron-related metal powder for manufacturing a shielding metal into a predetermined mold; (b) forming a metal powder green compact having a groove with a predetermined size in a center of one surface thereof by mechanically pressing the iron-related metal powder; (c) forming an incompletely-sintered body having the groove by incompletely sintering the metal powder green compact; (d) putting an alloy powder for manufacturing a magnet into the groove of the incompletely-sintered body; (e) magnetically pressing the alloy powder form manufacturing a magnet put into the groove; and (f) forming a completely-sintered body by completely sintering a resultant structure of (e).
According to another aspect of the present invention, there is provided a method of manufacturing a magnet capable of using only a single pole, the method including: (a) providing an alloy powder for manufacturing a magnet, a first alloy powder green compact having an oriented powder formed by magnetically pressing the alloy powder for manufacturing a magnet, or a second alloy powder green compact formed by mechanically pressing the first alloy powder green compact; (b) providing an iron-related metal powder for manufacturing a shielding metal or an incompletely-sintered body formed by incompletely sintering a metal powder green compact of the iron-related metal powder for manufacturing a shielding metal; and (c) placing a resultant structure of (a) and a resultant structure of (b) so that at least one surface of the resultant structure of (a) is exposed and the remaining surfaces of the resultant structure of (a) are surrounded by the resultant structure of (b); and (d) forming a sintered body by sintering a resultant structure of (c).
According to another aspect of the present invention, there is provided a method of manufacturing a magnet capable of using only a single pole, the method including: (a) putting an iron-related metal powder for manufacturing a shielding metal into a predetermined mold; (b) forming a metal powder green compact having a groove with a predetermined size in a center of one surface thereof by mechanically pressing the iron-related metal powder; (c) forming an incompletely-sintered body having the groove by incompletely sintering the metal powder green compact; (d) forming a first alloy powder green compact having an oriented powder to correspond to a shape of the groove by magnetically pressing the alloy powder for manufacturing a magnet within the predetermined mold; (e) manufacturing a second alloy powder green compact by mechanically pressing the first alloy powder green compact; (f) inserting the second alloy powder green compact into the groove of the incompletely-sintered body; and (g) forming a completely-sintered body by completely sintering a resultant structure of (f).
The present invention will now be described more fully with reference to the accompanying drawings, in which exemplary embodiments of the invention are shown.
A method of manufacturing a magnet capable of using only a single pole according to the present invention may include: a first process of providing an alloy powder for manufacturing a magnet, a first alloy powder green compact having an oriented powder by magnetically pressing the alloy powder for manufacturing a magnet, or a second alloy powder green compact formed by mechanically pressing the first alloy powder green compact; a second process of providing an incompletely-sintered body formed by incompletely sintering an iron-related metal powder for manufacturing a shielding metal or a metal powder green compact of the iron-related metal powder for manufacturing a shielding metal; a third process of placing a resultant structure of the first process and a resultant structure of the second process so that at least one surface of the resultant structure of the first process is exposed and the remaining surfaces thereof are surrounded by the resultant structure of the second process; and a fourth process of forming a sintered body by sintering a resultant structure of the third process, and may further include: a fifth process of performing polishing, plating, and magnetization on the sintered body as a resultant structure of the fourth process.
Subsequently, specific example embodiments of the present invention will be described.
First, as illustrated in
The alloy powder 111a for manufacturing a magnet may include a fine powder of a neodymium (Nd)-iron (Fe)-boron (B)-based magnet alloy manufactured by preparing a bulk of the Nd—Fe—B-based magnet alloy using a strip cast method, for example, and grinding the bulk into a jet mill in an inert gas.
Next, as illustrated in
Next, as illustrated in
Next, as illustrated in
For example, after a compression process including magnetic pressing and mechanical pressing is performed, a sintering and heat treatment process is performed on a base material having a relative density of about 50% to about 60% at a high temperature so that the relative density of the base material is able to be close to 95% to 100%. When the relative density of the base material increases, a residual magnetic flux density Br and a mechanical strength of the base material can be increased, and sintering may be performed on the base material about 1,300° C., and three-step (1,100° C.-950° C.-500° C.) heat treatment can be performed on the base material.
Last, as illustrated in
For example, a barrel polishing method may be used in the polishing process as a process of assigning R-values to a surface and edges of the product before a surface treatment process is performed. An electroplating and electroless plating method may be used as the plating process as a process of preventing oxidation and corrosion of the product, and a nickel (Ni)-copper (Cu)—Ni multilayer plating method may be performed. The thickness of a film may be 10 to 25 μm in case of Ni and 5 to 10 μm in case of zinc (Zn). The magnetization process is a magnetization work of aligning magnetic spins in a predetermined direction by applying an external magnetic field to the product, and a magnetic-field strength of 1.5 to 3 times of coercivity of the product is required to be applied to the product so that saturation magnetization can be implemented (a work needs to be performed at 1500 volt/2,000 μF or higher.).
In the current embodiment, external shapes of the permanent magnet 111d and the shielding metal 121d may be changed according to the shapes of the first mold 110 and the second mold 120.
First, as illustrated in
Subsequently, as illustrated in
As illustrated in
Subsequently, as illustrated in
Last, as illustrated in
For example, a barrel polishing method may be used in the polishing process as a process of assigning R-values to a surface and edges of the product before a surface treatment process is performed. An electroplating and electroless plating method may be used as the plating process as a process of preventing oxidation and corrosion of the product, and a Ni—Cu—Ni multilayer plating method may be performed. The thickness of a film may be 10 to 25 μm in case of Ni and 5 to 10 μm in case of zinc (Zn). The magnetization process is a magnetization work of aligning magnetic spins in a predetermined direction by applying an external magnetic field to the product, and a magnetic-field strength of 1.5 to 3 times of coercivity of the product is required to be applied to the product so that saturation magnetization can be implemented (a work needs to be performed at 1500 volt/2,000 μF or higher.).
In order to adjust surface flatness after the processes of
In the current embodiment, external shapes of the shielding metal 211e and the permanent magnet 221c may be changed according to the shapes of the first metal 210 and the second metal 220.
First, as illustrated in
Subsequently, as illustrated in
Subsequently, as illustrated in
Subsequently, as illustrated in
Last, as illustrated in
For example, a barrel polishing method may be used in the polishing process as a process of assigning R-values to a surface and edges of the product before a surface treatment process is performed. An electroplating and electroless plating method may be used as the plating process as a process of preventing oxidation and corrosion of the product, and a nickel (Ni)-copper (Cu)—Ni multilayer plating method may be performed. The thickness of a film may be 10 to 25 μm in case of Ni and 5 to 10 μm in case of zinc (Zn). The magnetization process is a magnetization work of aligning magnetic spins in a predetermined direction by applying an external magnetic field to the product, and a magnetic-field strength of 1.5 to 3 times of coercivity of the product is required to be applied to the product so that saturation magnetization can be implemented (a work needs to be performed at 1500 volt/2,000 μF or higher.).
In order to adjust surface flatness after the processes of
In the current embodiment, external shapes of the shielding magnet 211e may be changed according to the shapes of the first mold 310, and the iron-related metal powder 311a may be mechanically pressed in the process of
First, as illustrated in
Subsequently, as illustrated in
As illustrated in
Subsequently, as illustrated in
Last, as illustrated in
For example, a barrel polishing method may be used in the polishing process as a process of assigning R-values to a surface and edges of the product before a surface treatment process is performed. An electroplating and electroless plating method may be used as the plating process as a process of preventing oxidation and corrosion of the product, and a Ni—Cu—Ni multilayer plating method may be performed. The thickness of a film may be 10 to 25 μm in case of Ni and 5 to 10 μm in case of zinc (Zn). The magnetization process is a magnetization work of aligning magnetic spins in a predetermined direction by applying an external magnetic field to the product, and a magnetic-field strength of 1.5 to 3 times of coercivity of the product is required to be applied to the product so that saturation magnetization can be implemented (a work needs to be performed at 1500 volt/2,000 μF or higher.).
In order to adjust surface flatness after the processes of
In the current embodiment, external shapes of the shielding metal 411e and the permanent magnet 421e may be changed according to the shapes of the first mold 410 and the second mold 420.
In the permanent magnet, a magnetic line is formed in a fully-opened state, as illustrated in
That is, in the magnetic field of the permanent magnet, an attractive force and a repulsive force are differently generated according to a metal, and degrees thereof varies according to permeability of the metal. When a metal having high permeability is close to the permanent magnet, the flow of the magnetic field is changed. Also, when the metal is close to the permanent magnet after the shape and the thickness of the metal are properly designed, directivity of the magnetic field through induction of the flow of the magnetic field can be changed.
Thus, the yoke can be integrally combined with the permanent magnet by changing the material, thickness and shape of the yoke according to the degree of reinforcement of a required magnetic force and the degree of shielding. Thus, a reinforcement ratio and a shielding ratio of the shielding magnet can be changed.
Thus, like in the above-described embodiment of the present invention, a shielding magnet 150, 240, 340 or 440 including a permanent magnet 111d, 221c, 321d, or 421e having one exposed surface and the remaining surfaces surrounded by a shielding metal 121d, 211e, 311e, or 411e as a yoke may generate the magnetic line illustrated in
As described above, according to the present invention, because combination of an alloy powder for manufacturing a magnet that constitutes a permanent magnet (magnet) and a yoke (a shielding metal) and an iron-related metal powder for manufacturing a shielding metal is performed during processes (for example, compression, sintering, etc.) required to manufacture a magnet, a combination force therebetween can be greatly increased without additionally performing an existing manual bonding work, and a shielding magnet, i.e., a magnet capable of using only a single pole, as a final base material is formed as one sintered body so that the efficiency of subsequent processes such as polishing, plating and magnetization after sintering and the completeness of the product can be improved.
Thus, compared to a conventional shielding magnet in which a permanent magnet and a yoke are bonded to each other using an additional manual work and are combined with (joined to) each other, an adhesion can be greatly improved, and labor costs and a working time can be greatly reduced, the unit price of the product can be reduced, and the efficiency of a manufacturing process and the completeness of the product can be improved.
While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the following claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2016-0079855 | Jun 2016 | KR | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/KR2017/006737 | 6/27/2017 | WO | 00 |
