Magnet component

Abstract

To provide a magnet component for reducing and controlling electromagnetic waves emitted from electronic devices and external electromagnetic waves affecting electronic devices, such that an electromagnetic wave absorber such as ferrite is reliably protected and prevented from damage.SOLUTION: In a magnetic body component 1, all or part of the surface of ferrite, which serves as a magnet 3, is covered with a protective member 2 made of elastomer.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a magnetic part for reducing and controlling electromagnetic waves generated by electronic devices or electromagnetic waves that affect electronic devices. [Background technology]

[0002] Conventionally, electromagnetic wave countermeasures have used magnetic materials such as ferrite, which are electromagnetic wave absorbers. As a component for electromagnetic wave countermeasures, a ferrite sheet has been proposed in which a flat ferrite core is attached to a protective sheet via an adhesive layer (Patent Document 1). In this ferrite sheet, a polyester film with electrical insulation and elasticity is used for the protective sheet. The protective sheet is attached only to one side of the ferrite core, and the ferrite core is installed in a partially exposed state.

[0003] However, in the prior art of Patent Document 1, a protective sheet made of easily breakable polyester film is used, so the ferrite core is not sufficiently protected, the ferrite core is easily broken, and there is a problem that the broken pieces may damage other components. Also, since the ferrite core is installed in a partially exposed state, the ferrite core is not sufficiently protected, the ferrite core is easily broken, and there is a problem that the broken pieces may damage other components.

[0004] Another electromagnetic wave suppression component has been proposed, in which multiple small, plate-like ferrite plates are arranged horizontally inside a protective sheet made of a polymeric material such as silicone resin or acrylic resin (Patent Document 2). According to the conventional technology of Patent Document 2, the ferrite plate is completely covered by the protective sheet, which is more effective at preventing damage to the ferrite plate than the conventional technology of Patent Document 1. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2007-273671 A [Patent Document 2] JP 2009-170548 A Summary of the Invention [Problem to be solved by the invention]

[0006] However, the electromagnetic wave suppression sheets described in Patent Documents 1 and 2 have a problem in that the protective sheet for the magnetic body (electromagnetic wave absorber) is made of a hard synthetic resin sheet, and therefore the elastic limit of the protective sheet is small and the elasticity is insufficient, so that the protective sheet itself is likely to be damaged by stress such as bending or pressing on the electromagnetic wave suppression sheet, and further, damage to the protective sheet makes the protection of the ferrite insufficient, making the ferrite prone to damage.In addition, if the ferrite is damaged, fragments may fly off, causing damage to other parts or causing injury to the user.

[0007] Furthermore, the electromagnetic wave suppression sheets described in Patent Documents 1 and 2 have a problem in that the protective sheet for the electromagnetic wave absorber is made of a synthetic resin sheet, and therefore the protective sheet has a high elastic modulus and low flexibility, so that stress caused by bending, pressing, etc. on the electromagnetic wave suppression sheet is directly applied to the ferrite, making the ferrite susceptible to damage. Also, when the electromagnetic wave suppression sheet comes into contact with other components, the protective sheet cannot absorb the unevenness of the other components, limiting the installation location and reducing the degree of freedom in installation.

[0008] Therefore, the present invention aims to reliably protect a magnetic body, such as ferrite, which is an electromagnetic wave absorber, in a magnetic body part for reducing and controlling electromagnetic waves, and to prevent damage to the electromagnetic wave absorber. Another aim is to prevent fragments from scattering even if the magnetic body, such as ferrite, which is an electromagnetic wave absorber, is damaged, thereby preventing damage to other parts and injury to the user. Another aim is to absorb the unevenness of other parts when contacting with other parts during installation, in a magnetic body part for reducing and controlling electromagnetic waves, and to increase the freedom of installation by making it less likely to restrict the installation location. [Means for solving the problem]

[0009] The present invention, as a means for solving the above problems, is a magnetic part comprising one or more magnetic bodies, the magnetic bodies being covered with an elastomer protective member.

[0010] In the magnetic component, the magnetic body is a magnetic component in which a part or the whole of the magnetic body is covered with an elastomer protective member.

[0011] In the magnetic component, the magnetic material is made of ferrite.

[0012] In the magnetic component, the magnetic body is made of ferrite, and the entire surface of the magnetic body is covered with the elastomer protective member.

[0013] In the magnetic component, at least a portion of the magnetic body is covered with the elastomer protective member, and an adhesive is laminated between the magnetic body and the elastomer protective member.

[0014] In the above magnetic part, a portion of the magnetic body is covered with the elastomeric protective member, and the portion of the magnetic body that is not covered with the elastomeric protective member is covered with an adhesive.

[0015] In the magnetic part, the elastomer protective member is made of rubber, a thermoplastic elastomer, or a thermosetting elastomer other than rubber.

[0016] In the magnetic part, the magnetic body is a plate-shaped, rod-shaped, block-shaped or ring-shaped magnetic part.

[0017] The magnetic component may further include a heat sink.

[0018] In the magnetic component, the heat dissipating body is a powdered and / or granular thermally conductive material.

[0019] In the magnetic component, the heat sink is a sheet-shaped magnetic component. Effect of the Invention

[0020] According to the present invention, in the magnetic part for reducing and controlling electromagnetic waves, the magnetic body is covered with an elastomer protective member, so that it is possible to reliably protect the magnetic body, which is an electromagnetic wave absorber such as ferrite, and prevent the magnetic body from being damaged. Moreover, by covering the entire surface of the magnetic body with the elastomer protective member, it is possible to more reliably protect the magnetic body, which is an electromagnetic wave absorber, and prevent the electromagnetic wave absorber from being damaged. Moreover, even if the magnetic body, which is an electromagnetic wave absorber such as ferrite, is damaged, it is possible to prevent the fragments from scattering, and to prevent damage to other parts and injury to the user. Moreover, in the magnetic part for reducing and controlling electromagnetic waves, the magnetic body is covered with an elastomer protective member, so that when it comes into contact with other parts during installation, it is possible to absorb the unevenness of other parts, and the installation location is less likely to be restricted, and it is possible to increase the degree of freedom of installation. [Brief description of the drawings]

[0021] [Figure 1] A perspective view of an embodiment of the present invention [Diagram 2] Figure 1A-A cross section [Diagram 3] Manufacturing process diagram of one embodiment of the present invention [Figure 4] A perspective view of another embodiment of the present invention [Diagram 5] A perspective view of an embodiment of the present invention in which the magnetic material is partially covered [Figure 6] Side view of an embodiment equipped with a heat sink according to the present invention [Figure 7] Side view of an embodiment using the adhesive of the present invention DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] The magnetic part of the present invention is a magnetic part that includes one or more magnetic bodies, a part or the entirety of which is covered with an elastomer protective member.

[0023] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. As shown in Fig. 1 and Fig. 2, a magnetic part 1 is configured by installing a magnetic body 3 inside an elastomer protective member 2. The magnetic body 3 is in a plate shape, and there is one installed. The magnetic body 3 is not exposed from the elastomer protective member 2, and the entire surface of the magnetic body 3 is completely covered by the elastomer protective member 2 and installed inside the elastomer protective member 2.

[0024] The elastomer protective member 2 is a protective member made of an elastomer having softness, flexibility, and rubber-like elasticity. As the elastomer, rubber, a thermoplastic elastomer, or a thermosetting elastomer other than rubber can be used. Elastomers are preferable because they are superior in softness, flexibility, and elasticity compared to other polymeric materials, are low-cost, and various functions can be added by changing the compounding contents. Among elastomers, rubber is preferable because it is superior in softness, flexibility, and elasticity, and various functions can be easily added by changing the compounding contents.

[0025] The rubber is not particularly limited, and may be natural or synthetic rubber, either diene or non-diene rubber, as long as it is a rubber composed of a blend within a range that provides flexibility.

[0026] The thermoplastic elastomer may be, but is not limited to, a copolymer ethylene vinyl acetate resin (EVA), polyvinyl chloride (PVC), a polyurethane-based thermoplastic elastomer, etc. The thermosetting elastomer may be, but is not limited to, a thermosetting urethane elastomer, etc.

[0027] The thickness of the elastomer protective member 2 is not particularly limited and can be set to a predetermined thickness depending on the thickness of the magnetic body 3 to be embedded, but in order to reliably protect the magnetic body 3, it is preferable that the thickness be 0.1 mm or more from the surface of the magnetic body 3.

[0028] The magnetic body 3 is not particularly limited as long as it is a soft magnetic body, and ferrite, iron, permalloy, ferrosilicon, etc. can be used.

[0029] The magnetic body 3 is preferably made of ferrite (soft ferrite) because it has high electromagnetic wave absorption capacity and high electrical resistance. In addition, ferrite has high electrical resistance, so it is difficult for current to flow through it and is a material close to an insulator. Therefore, it has the characteristic of generating little heat, in other words, having little heat loss, and since there is little loss of magnetic energy of electromagnetic waves, it is possible to transmit magnetic force (energy) efficiently. Therefore, ferrite can be suitably used in charging devices for electric vehicles (EVs) and automated guided vehicles (AGVs). In recent years, ferrite has often been used as an electromagnetic wave adjustment member used together with a wireless power supply coil, so it is preferable to select ferrite as the magnetic body.

[0030] Ferrite is a material that absorbs magnetic flux well, and among ferrites, Mn-Zn ferrite is more preferable because it is effective against electromagnetic waves of relatively low frequencies (1 MHz or less), has high magnetic permeability, and has high magnetic flux density.

[0031] The size of the magnetic body 3 is not particularly limited as long as it is not exposed from the elastomer protective member 2 and can be installed inside the elastomer protective member 2, but particularly when the magnetic body 3 is ferrite, the thickness is preferably about 0.35 to 8 mm, and more preferably about 1 to 5 mm. This is because a thickness of 0.35 mm or more provides good performance in absorbing and controlling electromagnetic waves regardless of frequency, and a thickness of more than 8 mm is undesirable because the weight of the magnetic part 1 increases significantly and the part becomes heavy.

[0032] Here, the manufacturing method of the magnetic part 1 will be described by taking the case where the elastomer protective member is made of rubber as an example. As shown in FIG. 3, two elastomer sheets 20 made of unvulcanized rubber and one magnetic body 3, which are made of the same material as the elastomer protective member 2, are prepared (FIG. 3(a)). In a mold 91, the magnetic body 3 is placed on one of the elastomer sheets 20 (FIG. 3(b)), and the other elastomer sheet 20 is placed on top of the magnetic body 3, so that the magnetic body 3 is sandwiched between the two elastomer sheets 20 (FIG. 3(c)). Then, the mold 92 is fitted to the mold 91, and the mold 9 is closed to vulcanize the rubber, and the magnetic body 3 is fixed in a state where it is enclosed in the elastomer protective member 2 (FIG. 3(d)). In this way, the magnetic part 1 equipped with the magnetic body 3 is completed.

[0033] Although not shown, an adhesive may be laminated between the elastomer protective member 2 and the magnetic body 3, and the elastomer protective member 2 and the magnetic body 3 may be bonded together with the adhesive. With such a configuration, the magnetic body 3 can be more reliably fixed within the elastomer protective member 2. The adhesive may be made of a synthetic resin having flexibility and suppleness.

[0034] 1 and 2, the magnetic body 3 is plate-shaped and one magnetic body is installed, but the present invention is not limited to this form. Although not shown, two or more magnetic bodies of the same shape may be arranged vertically. A plurality of magnetic bodies may be arranged horizontally, or a plurality of magnetic bodies may be arranged horizontally and a plurality of magnetic bodies may be arranged vertically. When a plurality of magnetic bodies are installed, the magnetic bodies may all have the same shape, or may have different shapes.

[0035] Here, a manufacturing method for a magnetic part in the case where the magnetic bodies are arranged vertically regardless of the number of magnetic bodies arranged horizontally will be described using an example in which the elastomer sheets are made of rubber, although not shown in the figures. For example, when the magnetic bodies are arranged in two tiers vertically, three elastomer sheets in the form of unvulcanized rubber sheets and two magnetic bodies are prepared, which are the same material as the elastomer protective member, and the magnetic bodies are placed on the first elastomer sheet in a mold, covered with a second elastomer sheet, placed on the second elastomer sheet, covered with a third elastomer sheet, and the two magnetic bodies are alternately sandwiched between the three elastomer sheets. Then, the mold is closed to vulcanize the rubber, and the magnetic bodies are arranged vertically and fixed in a state where they are enclosed in the elastomer protective member. In this way, a magnetic part equipped with magnetic bodies arranged vertically is completed.

[0036] The magnetic part 1 shown in Fig. 1 and Fig. 2 is configured in a sheet shape with a plate-shaped magnetic body 3 embedded in a sheet-shaped elastomer protective member 2, but the shapes of the magnetic part and the elastomer protective member are not particularly limited, and can be in a plate shape, rod shape, block shape, ring shape, etc., depending on the intended use, installation location, shape of the magnetic body, etc. Also, the shape of the magnetic body is not particularly limited, and can be in a plate shape, rod shape, block shape, ring shape, etc., depending on the intended use, installation location, etc. Note that the magnetic part, the elastomer protective member, and the ring-shaped magnetic body include a completely circular shape without any breaks, as well as one with an opening in a part like the letter C.

[0037] The shapes of the magnetic parts, elastomer protective members and magnetic bodies are not limited to these, but some of them can be rectangular plates as shown in Figure 3, or the magnetic parts 11, elastomer protective members 21 and magnetic bodies 31 can be circular plates (Figure 4(a)), etc., and the cross section can be polygonal such as a rectangle or circular, and the magnetic parts 12, elastomer protective members 22 and magnetic bodies 32 can be straight rods (Figure 4(b)) or bent or curved rods, etc. In addition, the magnetic part 13, the elastomer protective member 23 and the magnetic body 33 can be in the shape of a rectangular block (Figure 4(c)), or a block shape such as a cone, pyramid, truncated cone, truncated pyramid, sphere, etc., and the magnetic part 14, the elastomer protective member 24 and the magnetic body 34 can be in the shape of a completely circular ring (Figure 4(d)) with a circular or square cross section, or the magnetic part 15, the elastomer protective member 25 and the magnetic body 35 can be in the shape of a ring with an opening in one part (Figure 4(e)).

[0038] In addition, although the magnetic parts shown in Figures 1 to 3 have a shape similar to or substantially the same as the shape of the magnetic body, the shape of the magnetic parts may be different from the shape of the magnetic body 3 by partially changing the thickness of the elastomer protective member, or by chamfering, etc.

[0039] Also, the magnetic part may be configured such that only a portion of the magnetic body is covered with an elastomer protective member. Such a configuration is not particularly limited, but may be, as shown in FIG. 5, a magnetic material part 14 (FIG. 5(a)) in which the magnetic material 34 is stacked between two elastomer protective members 24 having the same shape as the magnetic material 34 in a planar view, with the side surface 342 of the magnetic material 34 exposed; a magnetic material part 15 (FIG. 5(b)) in which the magnetic material 35 is stacked on one elastomer protective member 25, with the top surface 351 and the side surface 352 of the magnetic material 35 exposed; a magnetic material part 16 (FIG. 5(c)) in which a rectangular parallelepiped magnetic material 36 is embedded in one elastomer protective member 26 with only one surface, here the top surface 361, exposed; and a magnetic material part 17 (FIG. 5(d)) in which a rod-shaped magnetic material 37 is embedded in a rod-shaped elastomer protective member 27 with both end surfaces 371 exposed. Even in the case where only a portion of the magnetic body is covered with the elastomer protective member, the magnetic body can be in the shape of a plate, a rod, a block, or the like as described above.

[0040] Furthermore, when the magnetic component is configured to include multiple magnetic bodies, the entire surfaces of all of the magnetic bodies may be covered with an elastomeric protective member, or some of the magnetic bodies may be partially covered with an elastomeric protective member and some of the magnetic bodies may be entirely covered with an elastomeric protective member, or all of the magnetic bodies may be partially covered with an elastomeric protective member.

[0041] When multiple magnetic bodies are arranged horizontally or vertically, an elastomer protective member is interposed between adjacent magnetic bodies, but it may be configured not to be interposed. Even if an elastomer protective member is not interposed between adjacent magnetic bodies, it is also possible to configure the magnetic bodies so that all magnetic bodies are covered with the elastomer protective member and the magnetic bodies are not exposed on the surface of the magnetic body part.

[0042] 6(a), the magnetic part 191 may include a heat sink 5. The heat sink 5 is a member for imparting heat dissipation to the magnetic part 191, and can be made of a powdered or / and granular thermally conductive material. As the thermally conductive material, for example, a ceramic solid material having a thermal conductivity [W / (m·K)] of two or more digits, such as alumina, magnesium oxide, or aluminum nitride, can be suitably used. On the other hand, metals and alloys are conductive and electric current easily flows through them, so they are not used as a heat sink in the present invention.

[0043] The heat sinks 5 are disposed in a dispersed manner inside and / or on the surface of the elastomer protective member 2. When the elastomer protective member 2 is made of rubber, it is preferable to mix 50 to 200 parts by weight of the heat sink 5 with 100 parts by weight of the rubber. If the amount mixed is less than this, the thermal conductivity is insufficient, and if the amount mixed is more than this, the flexibility of the elastomer protective member 2 deteriorates. In order to achieve a good balance between thermal conductivity and flexibility, it is more preferable to mix 75 to 200 parts by weight of the heat sink with 100 parts by weight of the rubber of the elastomer protective member.

[0044] 6(b), the heat sink 6 may be a known heat conductive sheet formed in a sheet shape. The sheet-shaped heat sink 6 may be disposed inside or on the surface of the magnetic sheet 2, but is preferably disposed on the surface of the magnetic component 192 from the viewpoint of heat dissipation.

[0045] Furthermore, the elastomer protective member may contain a flame-retardant substance to impart flame retardancy to the magnetic parts. Examples of the flame-retardant substance include halogen-based compounds such as tetrabromobisphenol A (TBBPA), phosphorus-based compounds such as triphenyl phosphate, and antimony-based compounds such as antimony trioxide. Metals and alloys such as metal foils and plating are excluded from the flame-retardant substance in the present invention because they are conductive and allow current to flow easily. Also, known substances may be blended into the magnetic parts to impart heat resistance, ozone resistance, and the like.

[0046] When a powder or granular heat sink, flame retardant, heat resistant, or ozone resistant substance is to be contained in the magnetic part, the substance can be held or contained in the elastomer protective member. As a manufacturing method thereof, when the elastomer protective member is made of rubber, particles of the substance can be kneaded into unvulcanized rubber to form an elastomer sheet, and the magnetic part can be manufactured using the elastomer sheet as described above.

[0047] As another embodiment of the magnetic part, in the case where only a portion of the magnetic body is covered with an elastomer protective member, as shown in Fig. 7(a), a magnetic part 181 may be configured such that an adhesive 7 is laminated between an elastomer protective member 28 and a magnetic body 38, and the elastomer protective member 28 and the magnetic body 38 are bonded with the adhesive 7. As shown in Fig. 7(b), a magnetic part 182 may be configured such that the magnetic body 38 is fixed on the elastomer protective member 28, a portion of the magnetic body 38 is covered with the elastomer protective member 28, and a portion or the entire portion of the magnetic body 38 that is not covered with the elastomer protective member 28 is covered with the adhesive 7. Also, as shown in FIG. 7(c), the magnetic part 183 may be configured such that an adhesive 7 is laminated between the elastomer protective member 2 and the magnetic body 3, the elastomer protective member 28 and the magnetic body 38 are bonded with the adhesive 7, a part of the magnetic body 38 is covered with the elastomer protective member 28, and a part or all of the part of the magnetic body 38 that is not covered with the elastomer protective member 28 is covered with the adhesive 7. With such a configuration, the elastomer protective member and the magnetic body can be fixed more reliably. The adhesive 7 also has the effect of preventing oxidation of the magnetic body and preventing metal corrosion by chlorine-based gas. The adhesive 7 can be made of a synthetic resin having flexibility and flexibility.

[0048] Furthermore, although not shown, an adhesive layer made of a pressure sensitive adhesive or a bonding agent may be provided on the bottom or top surface of the magnetic component so that the magnetic component can be attached to an electronic device or electronic component.

[0049] The magnetic component of the present invention can be used for, but is not limited to, preventing noise radiation from cables and board patterns, preventing noise induction between boards, and preventing a decrease in transmission efficiency in wireless power supply systems. EXAMPLES

[0050] The magnetic parts shown in Table 1 were produced, and their impact resistance was measured. As shown in Fig. 3, the magnetic part of Example 1 was produced by preparing two elastomer sheets 20 of unvulcanized rubber and one Mn-Zn ferrite PC95 (manufactured by TDK Corporation) as a plate-shaped magnetic body 3, which were made of the same material as the elastomer protective member 2 (Fig. 3(a)), placing the magnetic body 3 on one of the elastomer sheets 20 in a mold 91 (Fig. 3(b)), placing the other elastomer sheet 20 on top of the magnetic body 3, and sandwiching the magnetic body 3 between the two elastomer sheets 20 (Fig. 3(c)), matching the mold 92 to the mold 91, closing the mold 9, vulcanizing the rubber, and fixing the magnetic body 3 in a state of being enclosed in the elastomer protective member 2 (Fig. 3(d)), thereby producing a magnetic part 1 equipped with the magnetic body 3. A bare plate-like ferrite PC95 without a protective member was used as Comparative Example 1, and a magnetic part with a commercially available acrylic plate made of acrylic resin as a protective member was used as Comparative Example 2. The thickness of the protective member in Example 1 and Comparative Example 2 was 1 mm, and the protective member completely covered the ferrite as a magnetic body with a length of 100 mm, a width of 100 mm, and a thickness of 5 mm.

[0051] Then, the parts of Example 1, Comparative Example 1, and Comparative Example 2 were dropped from a height of 2 m, and the state of the magnetic body 3 after the drop was observed. A case in which the ferrite as the magnetic body 3 did not crack was deemed to be pass, and is indicated by ○ in Table 1, and a case in which the ferrite cracked was deemed to be fail, and is indicated by × in Table 1. The results are shown in Table 1.

[0052] [Table 1]

[0053] As is clear from Table 1, Example 1, which used an elastomer protective member, has superior impact resistance compared to Comparative Example 1, which did not use a protective member, and Comparative Example 2, which used an acrylic resin as a protective member. [Industrial Applicability]

[0054] The magnetic material parts of the present invention as described above are capable of absorbing, shielding, reducing and controlling electromagnetic waves, and can reliably protect magnetic materials that are electromagnetic wave absorbers such as ferrite and prevent damage, making them extremely useful as electronic components and parts for electronic equipment. [Explanation of symbols]

[0055] 1 Magnetic parts 2 Elastomer protective material 20 Elastomer seat 3 Magnetic material 5 Granular heat sink 6 Sheet-shaped heat sink 7. Glue 9. Mold

Claims

1. A magnetic part comprising one or more magnetic bodies, the magnetic bodies being covered with an elastomer protective member.

2. 2. The magnetic part according to claim 1, wherein the magnetic body is covered partly or entirely with an elastomer protective member.

3. 2. The magnetic part according to claim 1, wherein the magnetic material is ferrite.

4. 2. The magnetic part according to claim 1, wherein the magnetic body is made of ferrite, and the entire surface of the magnetic body is covered with the elastomer protective member.

5. 2. The magnetic component according to claim 1, wherein at least a portion of the magnetic body is covered with the elastomer protective member, and an adhesive is laminated between the magnetic body and the elastomer protective member.

6. 2. The magnetic part according to claim 1, wherein a portion of the magnetic body is covered with the elastomer protective member, and a portion of the magnetic body not covered with the elastomer protective member is covered with an adhesive.

7. 7. The magnetic part according to claim 1, wherein the elastomer protective member is made of rubber, a thermoplastic elastomer, or a thermosetting elastomer other than rubber.

8. 7. The magnetic part according to claim 1, wherein the magnetic body is in the shape of a plate, a rod, a block or a ring.

9. The magnetic part according to claim 7, wherein the magnetic body is in the shape of a plate, a rod, a block or a ring.

10. 7. The magnetic part according to claim 1, further comprising a heat sink.

11. 11. The magnetic part according to claim 10, wherein the heat sink is a powdered or / and granular thermally conductive material.

12. The magnetic part according to claim 10, wherein the heat sink is in a sheet shape.

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