KR20240059313A - Soft magnetic core assembly for wireless power charging with hybrid structure - Google Patents

Abstract

A hybrid soft magnetic core assembly for wireless power charging is provided.
The soft magnetic core assembly for wireless power charging of the present invention includes a first core ring composed of a soft magnetic material; and formed on the first core ring and composed of a soft magnetic alloy selected from Fe-Si-Al, Fe-Si, Fe-Ni, Fe-Ni-Mo, and Fe-Si-Cr and a polymer resin. Includes a second core ring.

Description

Hybrid soft magnetic core assembly for wireless power charging with hybrid structure}

The present invention relates to a hybrid soft magnetic core assembly that can be used for wireless power charging of various electronic devices, and more specifically, to a hybrid soft magnetic core for wireless power charging in which a polymer injection resin is laminated on a soft magnetic material sheet. It's about assemblies.

The possibility of wireless power transmission was proven in the early 1890s by N. Tesla, who established AC power commercialization technology, and was registered as a patent, but until recently it was used in the field of passive RF-ID (Radio frequency identification), magnetic induction heating devices, etc. Its use has been limited to only a few fields.

The main reason is that the power transmission efficiency is very low and commercialization has been difficult due to controversy over its harmfulness to the human body. However, thanks to the development of related technologies such as switching elements, antennas, and magnetic materials, solutions to existing problems have become possible, and recently, application products have been developed at a rapid pace.

In particular, wireless power transmission technology (WPC; wireless power charger), which is applied to portable electronic devices with built-in batteries, uses electromagnetic induction or magnetic resonance coupling between the power source and power receiver, so more portable electronic devices will be used in the future. Wireless charging will be available on the device.

In addition, in the future, the application of wireless power transmission technology is being considered in tablet PCs, laptop PCs, home appliances, electric vehicles, electric buses, and even monorails and trains that require greater power consumption.

On the other hand, soft magnetic materials used as electromagnetic field induction materials are magnetic materials in which the magnetization direction inside the material responds easily to the phase change of an external alternating magnetic field. Phenomenologically, they attract the magnetic field distributed in space into the material to create a high magnetic field. It plays a role in forming a magnetic induction circuit with a magnetic flux of density. At this time, the permeability of the magnetic material is an indicator of the degree to which the magnetic flux is increased. When a soft magnetic material with high permeability is used, most of the magnetic field distributed around the material is drawn into the material to minimize the leakage magnetic field.

Magnetic materials use single materials such as magnetic metal alloy and soft-ferrite sintered body, or mix metal magnetic powder and soft-ferrite sintered powder with resin, ceramic, or non-magnetic metal and form them through manufacturing processes such as extrusion, pressing, and casting. It is made of a heterogeneous composite material structure. In particular, in the case of soft-ferrite materials, Mn-Zn based spinel ferrite and Ni-Zn based ferrite materials can be used below 100 MHz, and at frequencies above that, Ba or Sr with a Z-type or Y-type hexagonal crystal structure can be used. Ferrite, etc. can be used. In the case of metallic magnetic materials, the magnetic permeability is lower than that of sintered ferrite in the low frequency band, but the magnetic loss is small, so the difference decreases in the high frequency band, so the efficiency is high.

Figure 1 is a diagram schematically showing a conventional core ring 10 for wireless charging. As shown in Figure 1, the conventional core ring is made of soft magnetic ferrite sintered body, and a coil is wound on its surface.

However, the core ring 10 made of the soft magnetic ferrite sintered body has excellent mass production properties, thermal stability of magnetic properties, high frequency characteristics, etc., but has the problem of being brittle and easily broken even by a small impact, and thus charging. Efficiency is gradually decreasing, causing product defects. Figure 2 is a photograph showing the core ring made of this ferrite sintered body broken by impact.

Therefore, there continues to be a demand for the development of a core assembly for wireless charging that is not only excellent in mass production, thermal stability of magnetic properties, and high frequency characteristics, but is also resistant to shock.

The purpose of the present invention is to provide a hybrid soft magnetic core assembly for wireless power charging that is excellent in mass production, thermal stability of magnetic properties, high frequency characteristics, etc., as well as resistance to shock.

In addition, the technical problems to be achieved in the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned can be clearly understood by those skilled in the art from the description below. It could be.

Therefore, one aspect of the present invention is,

A first core ring composed of a soft magnetic material; and

It is formed on the first core ring and is composed of a soft magnetic alloy selected from Fe-Si-Al, Fe-Si, Fe-Ni, Fe-Ni-Mo, and Fe-Si-Cr and a polymer resin. 2. It relates to a hybrid soft magnetic core assembly for wireless power charging comprising a core ring.

The soft magnetic material may be one type of soft magnetic alloy selected from Fe-Si-Al, Fe-Si, Fe-Ni, Fe-Ni-Mo, and Fe-Si-Cr.

The soft magnetic material may be a nanocrystalline amorphous alloy.

When the soft magnetic material is a soft magnetic alloy, the first core ring may have an inclined portion inclined upward from the outer peripheral surface to the inner peripheral surface.

When the soft magnetic material is a soft magnetic alloy, the first core ring may contain 10 to 30% by weight of a polymer resin made of one of urethane resin, polyethylene resin, acrylic resin, or rubber. there is.

The second core ring may include one type of polymer resin among nylon-based resin, PP-based resin, or ABS resin.

The second core ring may contain the soft magnetic alloy in a range of 85% or less by weight.

The second core ring may contain the soft magnetic alloy in the range of 60 to 85% by weight.

The surface of the second core ring may have a coil guide surface that guides the winding of the coil.

One or more locking protrusions for fixing the coil to be wound may be formed on the inner peripheral surface of the second core ring.

When the soft magnetic material constituting the first core ring is a soft magnetic alloy, a third core ring made of a nanocrystalline amorphous alloy may be further included on the lower surface of the first core ring.

The present invention, configured as described above, effectively provides a hybrid soft magnetic core assembly for wireless power charging that has excellent mass productivity, thermal stability of magnetic properties, high frequency characteristics, etc., as well as excellent resistance to shock. can do.

Figure 1 is a diagram schematically showing a conventional wireless charging core.
Figure 2 is a photograph showing a core ring made of a conventional ferrite sintered body broken by impact.
Figure 3 is a diagram schematically showing a hybrid soft magnetic core assembly for wireless power charging according to an embodiment of the present invention.
FIG. 4 is a cross-sectional view taken along line A-A' of the first core ring of FIG. 3.
Figure 5 is a diagram showing a coil wound around the core assembly of Figure 3.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

Figure 3 is a diagram schematically showing a hybrid soft magnetic core assembly for wireless power charging according to an embodiment of the present invention.

As shown in FIG. 3, the hybrid soft magnetic core assembly 100 for wireless power charging of the present invention includes a first core ring 130 composed of a soft magnetic material.

And the first core ring 130 includes a soft magnetic material having a magnetic permeability of u _i = 50.0 or more. Specifically, in the present invention, the soft magnetic alloy includes Fe-Si-Al, Fe-Si, Fe-Ni, One type of alloy material selected from Fe-Ni-Mo and Fe-Si-Cr can be used. Alternatively, the soft magnetic material may be a nanocrystalline amorphous alloy material.

In the present invention, the soft magnetic alloy may be made of metallic magnetic powder in the form of flakes.

In addition, when using a soft magnetic alloy as a soft magnetic material in the first core ring 130, the first core ring is a polymer made of one of urethane resin, polyethylene resin, acrylic resin, or synthetic rubber in percent by weight. It may contain resin in the range of 10 to 30%.

In the present invention, the flake-shaped soft magnetic alloy powder is mixed with resin, then a sheet is formed using a doctor blade or casting equipment, and the formed sheet is compressed with a hot press to form a high sheet density to form the first core ring. (130) can be manufactured.

Additionally, when a soft magnetic alloy is used as a soft magnetic material in the first core ring 130, the first core ring 130 may have an inclined portion 135 inclined upward from the outer peripheral surface to the inner peripheral surface. This inclined portion 135 acts as a reverse heel to concentrate the winding coils wound on the second core ring 150, which will be described later, more toward the center of the core ring. Accordingly, the magnetic flux density generated by the wound coil is also concentrated at the center of the core ring (130, 150), thereby increasing the induced electromotive force, and the inductance is also increased accordingly, thereby improving wireless charging efficiency.

FIG. 4 is a cross-sectional view taken along line A-A' of the first core ring 130 of FIG. 3, and an inclined portion 135 sloping upward is provided from the outer peripheral surface to the inner peripheral surface.

The present invention is not limited to a specific inclination angle of the inclined portion 135, and various inclination angles can be used without limitation. In other words, it is not limited to a specific inclination angle condition as long as the effect of the above-described inclined portion 135 can be realized.

In addition, the hybrid soft magnetic core assembly 100 for wireless power charging of the present invention is formed on the first core ring 130 and includes Fe-Si-Al, Fe-Si, Fe-Ni, and Fe-Ni-Mo. and a second core ring 150 composed of a soft magnetic alloy selected from Fe-Si-Cr and a polymer resin. This second core ring 150 maintains the shape of the final product and is mainly made of pelletized polymer resin, such as nylon-based resin, PP (polypropylene)-based resin, or ABS (Acrylonitrile butadiene styrene)-based resin. After that, it can be effectively manufactured by injection molding using a conventional injection molding machine.

Meanwhile, in the present invention, in addition to the above effects, in order to further improve magnetic properties and resistance to impact, Fe-Si-Al, Fe-Si, Fe-Ni, and Fe-Ni are added to the second core ring 150. -It may contain flake-shaped soft magnetic metal alloy powder made of one type of alloy selected from Mo and Fe-Si-Cr. However, since the purpose of forming the second core ring 150 in the present invention is to maintain the shape of the product, taking this into consideration, the soft magnetic metal alloy is composed of 85% or less (including 0%) in weight percent. This is desirable. More preferably, it is limited to the range of 60 to 85%. The remaining component here is polymer resin.

Additionally, the surface of the second core ring 150 of the present invention may have a coil guide surface 153 that guides the winding of the coil.

Additionally, one or more fixing protrusions 155 may be formed on the inner peripheral surface of the second core ring 150 to secure the wound coil. This locking protrusion 155 may serve to keep the wound coil fixed without leaving its position during use of the electronic device.

Furthermore, the hybrid soft magnetic core assembly 100 for wireless power charging of the present invention is provided on the lower surface of the first core ring 130 when the soft magnetic material forming the first core ring 130 is a soft magnetic alloy. It may further include a third core ring 110 made of a nanocrystalline amorphous material.

The third core ring 110 is a ribbon-shaped ring sheet made of an amorphous alloy material and is a sheet that maximizes magnetic permeability by securing magnetic ability. That is, when it is insufficient to secure inductance as a high permeability sheet, a third core ring 110 made of an amorphous material can be formed on the lower surface of the first core ring 130 to have an additional higher permeability. there is.

Figure 5 is a diagram showing a coil wound around the core assembly of Figure 3.

The hybrid soft magnetic core assembly for wireless power charging of the present invention configured as described above not only has excellent magnetic properties and mass productivity comparable to the core assembly made of conventional soft magnetic ferrite sintered body, but also has excellent resistance to impact. there is.

Hereinafter, the present invention will be described in detail through examples.

(Example 1)

After preparing flake Sendust (Fe: 84.6% by weight, Si: 9.7% by weight, Al: 5.7% by weight) powder, it was mixed with rubber-based SBR resin. The mixed mixture was formed into a sheet using casting equipment, and the formed sheet was compressed with a hot press to produce a first core ring with a magnetic permeability of 250 and a thickness of 0.2T.

Thereafter, a core assembly was manufactured by laminating a second core ring made of a soft magnetic metal alloy and a polymer resin on the manufactured first core ring. Here, in this experiment, Sendust (Fe: 84.6% by weight, Si: 9.7% by weight, Al: 5.7% by weight) powder was prepared from the soft magnetic metal alloy and then mixed with nylon 6 polymer resin. At this time, the mixing ratio of the soft magnetic metal alloy mixed into the resin was varied as shown in Table 1 below, and the corresponding electrical properties, impact properties, and charging efficiency characteristics are shown in Tables 1, 2, and 3, respectively.

Specifically, the electrical properties were measured using a HIOKI 3522 measuring instrument to measure the change in inductance (μH) according to the amount of metal alloy added to the second core ring at a frequency of 100 kHz, and the results were compared with the conventional ferrite ceramic sintered core and are shown in Table 1 below. indicated.

In addition, the core assembly manufactured in this experiment was dropped from a height of 1M and an impact test was performed. The damage of the manufactured core is shown in Table 2 below in comparison with the conventional ferrite sintered core.

And the wireless charging efficiency of the core assembly manufactured in this experiment was measured compared to the conventional ferrite sintered core, and the results are shown in Table 3 below.

Sample No. Conventional materials invention Ferrite sintered core Hybrid core (sendust addition amount when manufacturing secondary core ring) 0% 80% 85% One 14.04 11.48 13.35 14.15 2 14.08 11.41 13.32 14.18 3 14.02 11.43 13.30 14.17 average 14.05 11.44 13.32 14.17

division Conventional materials Ferrite sintered core Hybrid core (sendust addition amount when manufacturing secondary coring) 60% 80% 85% Damage or deformation O X X X

division Conventional materials invention Ferrite sintered core Hybrid core (sendust addition amount when manufacturing secondary core ring) 0% 80% 85% Charging efficiency 65% 50% or less 58.3% 65.1%

As shown in Table 1-3 above, it can be confirmed that the hybrid core of the present invention not only has comparable magnetic properties and filling rate compared to the conventional ferrite sintered core, but also has the characteristic of not being easily damaged by impact.

(Example 2)

A nanocrystalline amorphous alloy sheet was prepared as the first core ring material. Specifically, this nanosheet had, in weight%, Fe: 81.5%, B: 1.9%, Si: 7.7%, Nb: 5.6%, Cu: 1.3. The composition including % was used. Meanwhile, the thickness of the nanocrystalline amorphous alloy prepared in this way was 0.2T and had a permeability of 2100.

Thereafter, a core assembly was manufactured by laminating a second core ring made of a soft magnetic metal alloy and a polymer resin on the manufactured first core ring. Here, in this experiment, Sendust (Fe: 84.6% by weight, Si: 9.7% by weight, Al: 5.7% by weight) powder was prepared from the soft magnetic metal alloy, and then mixed with nylon 66 polymer resin. Afterwards, the mixture was injection molded to manufacture a core assembly. At this time, the mixing ratio of the soft magnetic metal alloy mixed into the resin was varied as shown in Table 4 below, and the corresponding electrical properties, impact properties, and charging efficiency characteristics are shown in Tables 4, 5, and 6, respectively.

Specifically, the electrical characteristics were measured using a HIOKI 3522 measuring instrument to measure the change in inductance (μH) according to the amount of metal alloy added to the second core ring at a frequency of 100 kHz, and the results were compared with those of a conventional ferrite ceramic sintered core and are shown in the table below. It is shown in 4.

In addition, the core assembly manufactured in this experiment was dropped from a height of 1M and an impact test was performed. The damage of the manufactured core is shown in Table 5 below in comparison with the conventional ferrite sintered core.

And the wireless charging efficiency of the core assembly manufactured in this experiment was measured compared to the conventional ferrite sintered core, and the results are shown in Table 6 below.

Sample No. Conventional materials invention Ferrite sintered core Hybrid core (sendust addition amount when manufacturing secondary core ring) 0% 80% 85% One 14.04 12.01 13.61 14.28 2 14.08 11.98 13.63 14.27 3 14.02 12.03 13.61 14.28 average 14.05 12.01 13.62 14.28

division Conventional materials Ferrite sintered core Hybrid core (sendust addition amount when manufacturing secondary coring) 60% 80% 85% Damage or alteration O X X X

division Conventional materials invention Ferrite sintered core Hybrid core (sendust addition amount when manufacturing secondary core ring) 0% 80% 85% Charging efficiency 65% 50% or less 60.8% 65.8%

As shown in Table 4-6 above, the hybrid core manufactured using nanocrystalline amorphous alloy as the first core ring material not only has comparable magnetic properties and filling rate compared to the conventional ferrite sintered core, but also is easily resistant to impact. It can be confirmed that there is no damage.

As described above, the detailed description of the present invention has described preferred embodiments of the present invention, but those skilled in the art can make various modifications without departing from the scope of the present invention. Of course this is possible. Therefore, the scope of rights of the present invention should not be limited to the described embodiments, but should be determined by the claims described below as well as their equivalents.

Claims (11)

A first core ring composed of a soft magnetic material; and
It is formed on the first core ring and is composed of a soft magnetic alloy selected from Fe-Si-Al, Fe-Si, Fe-Ni, Fe-Ni-Mo, and Fe-Si-Cr and a polymer resin. A hybrid soft magnetic core assembly for wireless power charging comprising two core rings;
The method of claim 1, wherein the soft magnetic material is a soft magnetic alloy selected from Fe-Si-Al, Fe-Si, Fe-Ni, Fe-Ni-Mo, and Fe-Si-Cr, for wireless power charging. Hybrid soft magnetic core assembly.
The hybrid soft magnetic core assembly for wireless power charging according to claim 1, wherein the soft magnetic material is a nanocrystalline amorphous alloy.
The hybrid soft magnetic core assembly for wireless power charging according to claim 1, wherein when the soft magnetic material is a soft magnetic alloy, the first core ring has an inclined portion inclined upward from the outer peripheral surface to the inner peripheral surface.
The method of claim 2, wherein when the soft magnetic material is a soft magnetic alloy, the first core ring contains 10% by weight of a polymer resin made of one of urethane resin, polyethylene resin, acrylic resin, or synthetic rubber. Hybrid soft magnetic core assembly for wireless power charging, covering 30% coverage.
The hybrid soft magnetic core assembly for wireless power charging according to claim 1, wherein the second core ring includes a polymer resin selected from the group consisting of nylon-based resin, PP-based resin, and ABS-based resin.
The hybrid soft magnetic core assembly for wireless power charging according to claim 1, wherein the surface of the second core ring has a coil guide surface for guiding the winding of the coil.
The hybrid soft magnetic core assembly for wireless power charging according to claim 1, wherein one or more fixing jaws for fixing the coil to be wound are formed on the inner peripheral surface of the second core ring.
The hybrid soft magnetic core assembly for wireless power charging according to claim 1, wherein the second core ring contains the soft magnetic alloy in a range of 85% or less by weight.
The hybrid soft magnetic core assembly for wireless power charging according to claim 9, wherein the second core ring contains the soft magnetic alloy in the range of 60 to 85% by weight.
According to claim 1, When the soft magnetic material constituting the first core ring is a soft magnetic alloy, a third core ring made of a nanocrystalline amorphous alloy is placed on the lower surface of the first core ring. Hybrid soft magnetic core assembly for charging.

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