Noise-suppressing ring magnet and noise-suppressing component

Abstract

The present invention provides a split-type anti-noise ring magnet, which is difficult to manufacture using Fe-based nanocrystalline alloys and achieves excellent noise reduction. The anti-noise ring magnet is used by inserting a cable inside the magnet. The anti-noise ring magnet comprises a radially stacked soft magnetic metal strip. The anti-noise ring magnet is composed of multiple non-annularly split segments, with the split surfaces of the segments abutting against each other to form an annular shape. The product of the flatness FL of the split surfaces and the coercive force Hc of the segments (FL × Hc) is 7.0 μm·A / m or less. The flatness FL is the sum of the absolute values ​​of the maximum and minimum values ​​of a cross-sectional curve measured in accordance with JIS B 0601:2001.

Description

Technical Field

[0001] The present invention relates to a ring-shaped magnet for noise suppression and a member for noise suppression. Background Art

[0002] Conventionally, there is known an anti-noise component including an annular magnet and a core case housing the annular magnet, for reducing noise current conducted in a cable connected to an electronic device.

[0003] Patent Document 1 describes a split-type ferrite core structure that can be split into semicircular shapes and directly inserted into a power cable. Compared to non-split ferrite cores that do not split the circular ferrite core, this split-type noise suppression component offers superior convenience because it can be installed while the cable is connected.

[0004] Patent Document 2 describes a magnetic core formed by winding an Fe-based nanocrystalline alloy ribbon and a method for manufacturing the same. A non-dividable ring magnet using an Fe-based nanocrystalline alloy has excellent impedance characteristics over a wide frequency band compared to a ferrite core, and thus has a greater noise reduction effect.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent No. 2992269.

[0008] Patent Document 2: Japanese Patent No. 6137408. Summary of the Invention

[0009] Problems to be solved by the invention

[0010] However, because Fe-based nanocrystalline alloys are formed from thin, highly brittle metal ribbons, they are prone to defects, limiting their shape during molding. Consequently, there are no split-type anti-noise ring magnets using nanocrystalline alloys. Consequently, nanocrystalline alloy cores cannot be easily used like split-type ferrite cores.

[0011] Therefore, an object of the present invention is to provide a split-type anti-noise ring magnet that is difficult to produce using an Fe-based nanocrystalline alloy and that achieves an excellent noise reduction effect.

[0012] Solutions for solving problems

[0013] The gist of the present invention is as follows.

[0014] [1] A ring-shaped magnet for noise suppression, with a cable inserted inside.

[0015] The anti-noise annular magnet comprises soft magnetic metal strips stacked in radial direction.

[0016] The anti-noise annular magnet is composed of a plurality of non-annularly divided pieces, and the divided surfaces of the pieces are abutted against each other to form an annular shape for use.

[0017] The product FL×Hc of the flatness FL of the split surface and the coercive force Hc of the split piece is 7.0 μm·A / m or less.

[0018] The flatness FL is the sum of the absolute values ​​of the maximum value and the minimum value of the cross-sectional curve measured in accordance with JIS B 0601:2001.

[0019] [2] The anti-noise annular magnet according to [1], wherein the arithmetic mean roughness Ra and the maximum height roughness Rz of the divided surface satisfy Ra≤0.7 μm and Rz≤10 μm, respectively.

[0020] [3] The anti-noise ring magnet according to [1] or [2] above, wherein the ring pressure strength is 50 MPa or more.

[0021] [4] The anti-noise annular magnet according to any one of [1] to [3], wherein the impedance relative permeability μrz at a frequency of 100 kHz is 6000 or more.

[0022] [5] The anti-noise ring magnet according to any one of [1] to [4], wherein the soft magnetic metal strip contains an Fe-based nanocrystalline alloy.

[0023] [6] A noise suppression component comprising: the noise suppression annular magnet according to any one of [1] to [5] above; and

[0024] A split-type magnetic core shell is formed by connecting subshells in a manner that can be opened and closed to form a cylindrical shape. The subshells are shaped by dividing the cylinder into non-annular shapes, and each of the subshells contains one of the split pieces of the anti-noise annular magnet.

[0025] When the split core case is closed, the split surfaces of the split pieces abut against each other inside the split core case to form the anti-noise annular magnet, and the surface pressure applied to the split surfaces is 0.05 MPa or more.

[0026] Effects of the Invention

[0027] According to the present invention, a split-type anti-noise ring magnet that is difficult to produce using an Fe-based nanocrystalline alloy can be provided, and an excellent noise reduction effect can be obtained. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a top view of an example of a ring magnet for noise suppression.

[0029] Figure 2 This is a perspective view of an example of a ring magnet for noise suppression.

[0030] Figure 3 This is a diagram showing an example of a noise suppression member.

[0031] Figure 4 This is a diagram showing an example of a state in which the anti-noise member is opened.

[0032] Figure 5 This is a diagram showing an example of a state in which the anti-noise member is closed.

[0033] Figure 6 This figure explains a method for measuring the pressure ring strength of a ring magnet for noise suppression.

[0034] Figure 7 These are diagrams for explaining the measurement methods of flatness, arithmetic mean roughness Ra, and maximum height roughness Rz.

[0035] Figure 8 This is a diagram for explaining the measurement positions of flatness, arithmetic mean roughness Ra, and maximum height roughness Rz. DETAILED DESCRIPTION

[0036] The present invention will be described in detail below. In addition, in this specification, a numerical range expressed using "to" means a range including the numerical values ​​described before and after "to" as the lower limit and the upper limit.

[0037] [Anti-noise ring magnet]

[0038] The present invention is a ring-shaped magnet for noise reduction, which is used by inserting a cable inside the magnet.

[0039] The anti-noise annular magnet comprises soft magnetic metal strips stacked in radial direction.

[0040] The anti-noise annular magnet is composed of a plurality of non-annularly divided pieces, and the divided surfaces of the pieces are abutted against each other to form an annular shape for use.

[0041] The product FL×Hc of the flatness FL of the divided surface and the coercive force Hc of the divided piece is 7.0 μm·A / m or less.

[0042] The flatness FL is the sum of the absolute values ​​of the maximum and minimum values ​​of the cross-sectional curve measured in accordance with JIS B 0601:2001.

[0043] Figure 1 A plan view of a ring magnet 100 for noise suppression according to an embodiment of the present invention is shown. Figure 2 The following are three-dimensional views of a ring-shaped magnet 100 for noise suppression according to an embodiment of the present invention. As shown in these figures, the ring-shaped magnet 100 for noise suppression has an annular shape as a whole and includes thin soft magnetic metal strips stacked in radial directions. The ring-shaped magnet 100 for noise suppression is composed of a plurality of segments 1a and 1b that are non-annularly divided. Figure 1 and Figure 2 In the example, the anti-noise ring magnet 100, which is annular in shape as a whole, is divided into two halves along the central axis direction. Figure 1 and Figure 2 As shown, the divided surfaces of the plurality of divided pieces 1a and 1b are brought into contact with each other to form a ring shape, and the cable is inserted into the hollow portion 11 defined by the anti-noise annular magnet 100 for use.

[0044] Fe-based nanocrystalline alloys are laminated bodies of highly brittle soft magnetic thin metal strips, so their shapes are limited during molding, making them susceptible to damage and difficult to handle. Therefore, it is difficult to provide a split-type anti-noise ring magnet 100 using Fe-based nanocrystalline alloys. Even if a split-type anti-noise ring magnet 100 is made using Fe-based nanocrystalline alloys, due to their high brittleness, the management of the split surfaces becomes insufficient, and thus a sufficient noise reduction effect cannot be achieved.

[0045] The inventors of the present invention independently conducted extensive research and discovered that by managing the surface roughness of the split surfaces and the coercivity of the split pieces 1a and 1b so that the product (FL × Hc) of the split surface flatness FL and the coercivity Hc of the split pieces 1a and 1b is 7.0 μm·A / m or less, an excellent noise reduction effect, with an impedance relative permeability μrz of 6000 or greater at a frequency of 100 kHz, can be achieved. This led to the invention of the present anti-noise ring magnet 100. To achieve even better noise reduction, the product (FL × Hc) of the split surface flatness FL and the coercivity Hc of the split pieces 1a and 1b is preferably 6.5 μm·A / m or less, and more preferably 2.0 μm·A / m or less. The lower limit of the product (FL × Hc) of the split surface flatness FL and the coercivity Hc of the split pieces is not particularly limited, but is preferably 0.005 μm·A / m or greater, based on its relationship with the lower limits of flatness and coercivity described below.

[0046] Here, "flatness" refers to the sum of the absolute values ​​of the maximum and minimum values ​​of the cross-sectional curve of the split surface measured in accordance with JIS B 0601:2001. However, if the maximum value of the cross-sectional curve includes a noise peak, the maximum peak height Rp of the roughness curve is used as the maximum value. In addition, if the minimum value of the cross-sectional curve includes a noise peak, the peak value is not included in the calculation of flatness. For each split surface of the split pieces 1a and 1b (at Figure 1 、 Figure 2 In the example, a total of 4 surfaces were used), and a SURFCOM 1400G surface roughness measuring instrument manufactured by Tokyo Seimitsu Co., Ltd. was used to measure the cross-sectional curve along the stacking direction of the soft magnetic metal strips (the direction that crosses the stacked body of the soft magnetic metal strips, the radial direction of the anti-noise ring magnet 100). Figure 7 、 Figure 8 , describe the details of the measurement location. Figure 7 As shown, for the multiple split surfaces 10a and 10a' of each split piece 1a, measurements are performed on at least three positions of each split surface: the upper portion R1, R1', the middle portion R2, R2', and the lower portion R3, R3'. Figure 8 The dividing surface 10a is 50 mm in area, with the width of the soft magnetic metal strip (equivalent to the height of the anti-noise ring magnet 100 in the direction of the central axis) L = 10 mm and the length of the soft magnetic metal strip in the stacking direction (equivalent to the thickness of half the difference between the inner and outer diameters of the anti-noise ring magnet 100) e = 5 mm. 2 The measurement position of flatness in the case of Figure 8As shown, when the width L of the soft magnetic metal strip of the dividing surface 10a is 3mm<L<15mm, cross-sectional curves are measured at a total of three positions: (1) the upper portion R1 at the inner side of the end portion of the soft magnetic metal strip in the width L direction of the dividing surface 10a with w1=1mm; (2) the central portion R2 in the width L direction of the soft magnetic metal strip of the dividing surface 10a (the distance w2 from R1 and R3 is equal); and (3) the lower portion R3 at the inner side of the end portion of the other side of the width L of the soft magnetic metal strip of the dividing surface 10a with w1=1mm, and the flatness is determined based on the cross-sectional curves. As an exception, when the width L of the soft magnetic metal strip is 2 mm < L ≤ 3 mm, the cross-sectional curve is measured at two locations: upper portions R1 and R1', 1 mm inward from the end in the width L direction, and lower portions R3 and R3', 1 mm inward from the other end in the width L direction. When L = 2 mm, the cross-sectional curve is measured at a single location along the centerline of the width of the soft magnetic metal strip. When the width L of the soft magnetic metal strip is 15 mm or greater, additional measurement locations are added at 5 mm intervals. Next, the cross-sectional curve measurement length is explained. According to JIS B 0601:2001, the measurement length y1 of the soft magnetic metal strip in the stacking direction at the split surface 10a is 4 mm. The cross-sectional curve is measured at the center of the length e of the soft magnetic metal strip in the stacking direction at the split surface 10a. When the length e of the soft magnetic metal strip in the stacking direction at the split surface 10a is 8 mm or greater, additional measurement locations are added at 4 mm intervals. In the case where it is not possible to increase the measurement position every 4 mm, measure 4 mm of the central portion of the length e in the stacking direction. In addition, when the dividing surface is not a straight line but a curve, or has a step difference, the length of the stacking direction of the soft magnetic metal strip is used as the measured length, and the surface of the soft magnetic metal strip is not included in the measurement position. In the case where the anti-noise annular magnet 100 is composed of two dividing pieces 1a and 1b, the average value of the sum of the absolute values ​​of the maximum and minimum values ​​of the cross-sectional curve at a total of 12 positions is used as the flatness of the dividing surfaces 10a and 10b. In addition, the size of the dividing surface 10a of the anti-noise annular magnet 100 is measured using the same method as the size measurement method of the anti-noise annular magnet 100 described later.

[0047] In the present invention, the flatness of the resulting divided surfaces 10a and 10b can be adjusted by polishing the cut surface. Flatness can be adjusted by, for example, the mesh size of the polishing cloth used for polishing. As described later, if a protective layer such as a rust preventative or a film is applied to the divided surfaces 10a and 10b, the flatness of the divided surfaces 10a and 10b can be measured after the protective layer is applied.

[0048] The coercivity of the split pieces 1a and 1b is the average of three measurements using a Tokyo Special Steel automatic coercivity meter, model K-HC1000. The coercivity is measured with the split pieces 1a and 1b placed so that their split surfaces abut against each other in a ring-shaped configuration. The coercivity of the split pieces 1a and 1b can be adjusted by adjusting the material properties of the soft magnetic metal strip, the temperature and duration of the heat treatment of the soft magnetic metal strip, the method of splitting (cutting) the anti-noise ring magnet 100, and the polishing conditions of the cut surfaces.

[0049] The flatness FL is not particularly limited, as long as it is adjusted so that the product FL × Hc of the flatness FL of the divided surfaces 10a and 10b and the coercive force Hc of the divided pieces is 7.0 μm·A / m or less. The flatness is preferably 1.5 μm or less, and more preferably 0.7 μm or less. The lower limit of the flatness is not particularly limited, but from the perspective of mass production during machining, it is preferably 0.05 μm or greater.

[0050] The coercive force Hc is not particularly limited, as long as it is adjusted so that the product of the flatness FL of the split surfaces 10a and 10b and the coercive force Hc of the split pieces (FL × Hc) is 7.0 μm·A / m or less. The coercive force Hc is preferably 7.0 A / m or less, and more preferably 5.0 A / m or less. The lower limit of the coercive force is not particularly limited, but because the coercive force value varies depending on the material properties of the soft magnetic metal strip and the polishing conditions of the cross-section, it is preferably 0.1 A / m or greater.

[0051] The anti-noise annular magnet 100 is composed of a plurality of split pieces 1a and 1b that are split into non-annular shapes. The number and size of the split pieces that constitute the anti-noise annular magnet 100 are not particularly limited. Figure 1 、 Figure 2As shown, the anti-noise annular magnet 100 can be composed of two segments 1a and 1b, or it can be composed of more segments. In addition, the overall shape of the segments 1a and 1b of the anti-noise annular magnet 100 can be divided into any shape as long as it is non-annular. In one example, the anti-noise annular magnet 100 is divided in a manner parallel to the central axis direction. In addition, the central axis direction here refers to the direction on a straight line extending perpendicularly to the radial direction from the center of the anti-noise annular magnet 100. For example, each segment 1a and 1b can be a shape formed by dividing the anti-noise annular magnet 100 in the radial direction. According to this structure, even when the cable is connected to electronic equipment, electronic components, etc., the anti-noise annular magnet 100 can be inserted with the cable, so it is easy to install the anti-noise annular magnet 100 on the cable. Alternatively, after the plurality of split pieces 1a and 1b are brought into contact with each other, they may be bonded together so as to be immobilized. Alternatively, the split pieces 1a and 1b may be fixed to each other using a split core case or a tape described later.

[0052] The soft magnetic metal strip constituting the anti-noise annular magnet 100 is not particularly limited. In order to obtain an excellent noise reduction effect, a soft magnetic material with a small coercive force and a large impedance relative permeability is preferred. In order to obtain a particularly excellent noise reduction effect, the impedance relative permeability μrz of the soft magnetic metal strip constituting the anti-noise annular magnet 100 at a frequency of 100 kHz is preferably not less than 6000, and further preferably not less than 12000. In addition, in order to obtain a particularly excellent noise reduction effect, the coercive force of the soft magnetic metal strip constituting the anti-noise annular magnet 100 is preferably not more than 7.0 A / m.

[0053] As soft magnetic materials, ferrites such as Mn-Zn ferrite, Ni-Zn ferrite, and Ni-Zn-Cu ferrite; soft magnetic metals such as Fe-Ni alloys (Permalloy) and Fe-Si alloys (silicon steel); amorphous alloys such as Co-based amorphous alloys and Fe-based amorphous alloys; and Fe-based nanocrystalline alloys can be used.

[0054] The soft magnetic metal strip constituting the anti-noise ring magnet 100 is preferably an Fe-based nanocrystalline alloy. When the soft magnetic metal strip constituting the anti-noise ring magnet 100 is an Fe-based nanocrystalline alloy, for example, a Fe-based nanocrystalline alloy is particularly preferred. 1-a M a ) 100-x-y-z-b-c-d A x M' y M” z X b Si c B d(atomic %) (wherein, M represents at least one element selected from Co and Ni, A represents at least one element selected from Cu and Au, M' represents at least one element selected from Ti, V, Zr, Nb, Mo, Hf, Ta and W, M" represents at least one element selected from Cr, Mn, Sn, Zn, Ag, In, platinum group elements, Mg, N and S, X represents at least one element selected from C, Ge, Ga, Al and P, a, x, y, z, b, c and d are respectively An Fe-based nanocrystalline alloy having a general formula (a) satisfying a number (0≤a≤0.1, 0.1≤x≤3, 1≤y≤10, 0≤z≤10, 0≤b≤10, 11≤c≤17, and 3≤d≤10). The composition of the Fe-based nanocrystalline alloy is not particularly limited, but preferably comprises, in atomic %, 0.5-2.0% Cu, 1.0-5.0% Nb, 11.0-15.0% Si, 5.0-10.0% B, with the remainder consisting essentially of Fe.

[0055] To achieve a noise reduction effect, the arithmetic mean roughness Ra of the divided surfaces 10a and 10b is preferably Ra ≤ 0.7 μm, and more preferably Ra ≤ 0.35 μm. The lower limit of the arithmetic mean roughness Ra of the divided surfaces 10a and 10b is not particularly limited. The arithmetic mean roughness Ra of the divided surfaces 10a and 10b can be adjusted by polishing the cut surface. The arithmetic mean roughness Ra of the divided surfaces 10a and 10b can be adjusted by factors such as the mesh size of the polishing cloth used for polishing, the mesh size of the abrasive particles in the polishing suspension (a liquid containing the polishing abrasive particles), and the material of the abrasive particles.

[0056] To achieve excellent noise reduction, the maximum height roughness Rz of the divided surfaces 10a and 10b is preferably Rz ≤ 10 μm, more preferably Rz ≤ 5 μm. The lower limit of the maximum height roughness Rz of the divided surfaces 10a and 10b is not particularly limited. The maximum height roughness Rz of the divided surfaces 10a and 10b can be adjusted by polishing the divided surfaces 10a and 10b. The maximum height roughness Rz of the divided surfaces 10a and 10b can be adjusted by, for example, the mesh size of the polishing cloth used for polishing, the mesh size of the abrasive particles in the polishing suspension, and the material of the abrasive particles.

[0057] Here, the arithmetic mean roughness Ra and the maximum height roughness Rz of the split surfaces 10a and 10b were measured using a SURFCOM 1400G surface roughness measuring instrument manufactured by Tokyo Seimitsu Co., Ltd. on each split surface of the split pieces 1a and 1b (at Figure 1 、 Figure 2Measurements are performed at at least three locations on each of the four surfaces (in the example, a total of four surfaces), and the average values ​​of the at least 12 locations are used as the arithmetic mean roughness Ra and maximum height roughness Rz of the divided surfaces 10a and 10b. The measurement locations for the arithmetic mean roughness Ra and maximum height roughness Rz are the same as those for the flatness measurement described above.

[0058] The compression ring strength of the anti-noise ring magnet 100 is preferably 50 MPa or greater. Because the compression ring strength of the anti-noise ring magnet 100 is 50 MPa or greater, polishing the split surfaces 10a and 10b is easy. Furthermore, appropriate surface pressure can be applied to the split surfaces of the split pieces 1a and 1b to cause them to abut against each other. For reasons of ease of polishing and truncation, and easy shape maintenance, the compression ring strength of the anti-noise ring magnet 100 is more preferably 70 MPa or greater. The upper limit of the compression ring strength of the anti-noise ring magnet 100 is not particularly limited and can be 800 MPa or less.

[0059] The compression ring strength is measured as follows. Figure 6 As shown, the anti-noise ring magnet 100 was fixed using a jig 5 that matched its diameter so that the split surfaces 10a and 10b of the split pieces 1a and 1b of the anti-noise ring magnet 100 abutted against each other. The ring was then compressed perpendicularly to the split surfaces 10a and 10b while being measured using the Autograph AGX-20kNBVD manufactured by Shimadzu Corporation. The maximum load at which cracks develop was set to F, and the ring strength K was calculated as F(De) / Le. 2 Here, as Figure 2 As shown, D, L, and e are the outer diameter D, height L, and half the thickness e of the inner and outer diameter difference (the difference between the outer diameter D and the inner diameter d) of the anti-noise ring magnet 100. The dimensions of the anti-noise ring magnet 100 are measured by the method described below.

[0060] The compression ring strength of the anti-noise ring magnet 100 can be adjusted not only by adjusting the type of soft magnetic metal ribbon that constitutes the anti-noise ring magnet 100, but also by coating the anti-noise ring magnet 100 with resin or wrapping it with insulating tape. The compression ring strength can also be increased by impregnating the anti-noise ring magnet 100 with resin. Preferred resin coating agents or impregnating agents include epoxy resins, acrylic resins, or mixtures thereof.

[0061] The impedance relative permeability μrz of the anti-noise annular magnet 100 at a frequency of 100 kHz is preferably 6000 or greater, more preferably 8000 or greater, and even more preferably 12000 or greater. The upper limit of the impedance relative permeability μrz of the anti-noise annular magnet 100 at a frequency of 100 kHz is not particularly limited.

[0062] The impedance relative permeability μrz of the existing split-type ferrite core at a frequency of 100kHz is about 4000. In contrast, in the anti-noise annular magnet 100 of the present invention, an impedance relative permeability μrz of about 1.5 times the existing one can be obtained: 6000 or more, more preferably about 2.0 times the existing one: 8000 or more. In the anti-noise annular magnet 100 of the present invention, the noise suppression effect is much greater than that of the existing split-type ferrite core, which is related to the miniaturization and lightweighting of the anti-noise annular magnet 100. The cables of electronic components, power generation devices, power supply devices, communication equipment, etc. in automobiles are wired in narrow spaces. In addition, since electronic equipment such as inverters and converters in industrial machinery have also been miniaturized in recent years, wiring in narrow spaces is common. To achieve excellent noise reduction with existing split ferrite cores, it is necessary to increase the number of cable turns to enhance the noise reduction effect or to increase the volume occupied by the magnetic material. In contrast, the noise-reducing annular magnet 100 of the present invention achieves a noise suppression effect far greater than that of existing split ferrite cores, while also being compact and lightweight. Therefore, it can be installed in cables for electronic components, power generation devices, power supply devices, and communication equipment in automobiles, as well as cables for electronic equipment such as inverters and converters in industrial machinery. The noise-reducing annular magnet 100 is particularly effective in suppressing noise generated inside or outside these electronic components and electronic equipment and conducted through the cables.

[0063] The impedance relative permeability at a frequency of 100 kHz was measured as follows. A Keysight 4294A impedance analyzer was used for this measurement. A 0.5 mm Φ single-wire lead wire (H-PVC, manufactured by Tanaka Electric Cable) was passed through the noise suppression ring magnet 100 once. The measurement was performed using a lead wire jig (16047E, manufactured by Keysight) with a surface pressure of 0.1 MPa applied to the split surfaces 10a and 10b.

[0064] The overall shape of the anti-noise annular magnet 100 is not particularly limited as long as it is annular. Figure 1In addition to the true cylindrical shape shown (the outer shape of the cross section perpendicular to the central axis is a true circular ring), it can also be, for example, an elliptical cylindrical shape (the shape of the cross section perpendicular to the central axis is an elliptical ring), a square cylindrical shape (the shape of the cross section perpendicular to the central axis is a square ring), or a rounded square cylindrical shape (the shape of the cross section perpendicular to the central axis is a rounded square ring). The shape of the split pieces 1a and 1b is determined by the overall shape of the anti-noise ring magnet 100 and the method of segmentation. For example, if the overall shape of the anti-noise ring magnet 100 is a true cylindrical shape or an elliptical cylindrical shape, and the anti-noise ring magnet 100 is split symmetrically in half along the central axis, the shapes of the split pieces 1a and 1b can be arc-shaped. The overall shape of the anti-noise annular magnet 100 is a square tube with rounded corners, and when the anti-noise annular magnet 100 is divided into two halves symmetrically along the central axis, the shapes of the split pieces 1a and 1b can be "コ"-shaped, U-shaped, or straight-line according to the overall shape of the anti-noise annular magnet 100.

[0065] In addition, when the overall shape of the anti-noise ring magnet 100 is not annular, Figure 6 The clamp 5 is changed to a shape corresponding to the side surface of the anti-noise ring magnet 100, and the compression ring strength is measured. Furthermore, if the anti-noise ring magnet 100 includes three or more split pieces, the compression ring strength is determined when the anti-noise ring magnet 100 is split symmetrically in half along the central axis. This is used as the compression ring strength of the anti-noise ring magnet 100.

[0066] The size of the anti-noise ring magnet 100 is not particularly limited and can be set according to the purpose. In one example, the outer diameter D of the anti-noise ring magnet 100 can be greater than 10 mm, and can also be less than 300 mm. In one example, the inner diameter d of the anti-noise ring magnet 100 can be greater than 2 mm, and can also be less than 200 mm. The height L of the anti-noise ring magnet 100 in the direction of the central axis can be greater than 2 mm, and can also be less than 100 mm. In addition, in the case where the anti-noise ring magnet 100 is not a perfect circular ring, the outer diameter D and the inner diameter d are respectively equivalent to the outer diameter of the circle and the inner diameter of the circle. The average value of three measurements using a vernier caliper, a micrometer and a microscope image is obtained as the size of the anti-noise ring magnet 100.

[0067] exist Figure 1 、 Figure 2, an example of a straight line type in which the split surfaces 10a, 10b of the split pieces 1a, 1b are parallel to the stacking direction of the soft magnetic metal strips is shown, but the shape of the split surfaces 10a, 10b of the split pieces 1a, 1b is not particularly limited. The shape of the split surfaces 10a, 10b of the split pieces 1a, 1b can also be, for example, an inclined type, that is, the split surfaces 10a, 10b intersect with the stacking direction of the soft magnetic metal strips and are not parallel to the stacking direction of the soft magnetic metal strips. In addition, the split surfaces 10a, 10b can also be a shape that intersects with the central axis direction of the anti-noise ring magnet 100 and is not parallel to the central axis direction of the anti-noise ring magnet 100. In addition, the shape of the split surfaces 10a, 10b of the split pieces 1a, 1b is not limited to a plane. That is, the shape of the split surfaces 10a, 10b of the split pieces 1a, 1b is not limited to a straight line at the starting point and end point of the split and does not depend on the split path. When the dividing surfaces 10a and 10b are curved or have a step difference, the length of the soft magnetic metal strip in the stacking direction is used as the measurement length of the flatness, arithmetic mean roughness Ra and maximum height roughness Rz, and the stacking surface of the soft magnetic metal strip is not included in the measurement position.

[0068] The split surfaces 10a and 10b may also have a protective film formed of a rust preventative agent or a thin film sheet. Furthermore, the side surfaces (split side surfaces) that are continuous with the outer periphery of the split surfaces 10a and 10b of the noise suppressing ring magnet 100 may also be protected by resin coating or tape. The outer periphery (ends) of the split surfaces 10a and 10b may also be chamfered.

[0069] Preferably, the anti-noise annular magnet 100 is used by pressing with an appropriate load so that the surface pressure applied to the split surfaces 10a, 10b of the split pieces 1a, 1b is greater than 0.05 MPa when the split surfaces 10a, 10b are brought into contact with each other. In existing split-type ferrite cores, the surface pressure applied to the split surfaces 10a, 10b is approximately 0.025 MPa. However, when the split-type anti-noise annular magnet 100 is made of an Fe-based nanocrystalline alloy as described above, the management of the split surfaces 10a, 10b can easily become insufficient due to its high brittleness. Therefore, in addition to adjusting the surface roughness of the split surfaces 10a, 10b as described above, it is also possible to achieve a particularly excellent noise reduction effect by pressing with an appropriate load of 0.05 MPa or greater. The surface pressure applied to the split surfaces 10a, 10b is more preferably 0.10 MPa or greater. The upper limit of the surface pressure applied to the divided surfaces 10 a and 10 b is not particularly limited, but is preferably 5.0 MPa or less in order to effectively prevent deformation and damage of the divided surfaces 10 a and 10 b due to excessive load.

[0070] The surface pressure applied to the divided surfaces 10a, 10b of the divided pieces 1a, 1b was measured as follows: A pressure measuring film manufactured by Fujifilm Corporation was placed between the divided surfaces 10a, 10b of the divided pieces 1a, 1b and the surface pressure was measured for two minutes while the divided surfaces 10a, 10b were in contact with each other.

[0071] When the split surfaces 10a, 10b of the segments 1a, 1b of the anti-noise annular magnet 100 are brought into contact with each other so that the surface pressure applied to the split surfaces 10a, 10b is 0.05 MPa or more, for example, a tape or the like can be wrapped around the outer circumference of the anti-noise annular magnet 100 while the split surfaces 10a, 10b of the segments 1a, 1b are brought into contact with each other. Alternatively, the anti-noise annular magnet 100 can be housed in a split core housing, which is constructed by connecting sub-housings in an openable and closable manner to form a cylindrical shape, wherein the sub-housings are formed by dividing a cylindrical shape into non-annular portions. Within this split core housing, the surface pressure applied to the split surfaces 10a, 10b can be adjusted to 0.05 MPa or more. An anti-noise component including the aforementioned anti-noise annular magnet 100 will be described below.

[0072] [Noise suppression components]

[0073] A noise suppression member according to one embodiment includes:

[0074] Ring magnets for noise suppression; and

[0075] A split-type magnetic core shell is formed by connecting subshells in a manner that can be opened and closed to form a cylindrical shape. The subshells are shaped by dividing the cylinder into non-annular shapes, and each of the subshells contains one of the split pieces of the anti-noise annular magnet.

[0076] When the split core case is closed, the split surfaces of the split pieces abut against each other inside the split core case to form the anti-noise annular magnet, and the surface pressure applied to the split surfaces is 0.05 MPa or more.

[0077] use Figures 3 to 5 , an anti-noise component according to one embodiment will be described. Figures 3 to 5 FIG is a diagram showing an example of a noise-proof component. Figures 3 to 5As shown, the anti-noise component 200 has an anti-noise annular magnet 100 and a split core shell 60 that accommodates the anti-noise annular magnet 100. The split core shell 60 is formed by connecting the sub-shells 6a and 6b into a cylindrical shape through a hinge portion or the like so as to be able to open and close, wherein the sub-shells are shaped by dividing the cylinder in a non-annular shape. In one example, the split core shell 60 is formed by connecting the sub-shells 6a and 6b into a cylindrical shape through a hinge portion or the like so as to be able to open and close, wherein the sub-shells are shaped by dividing the cylinder parallel to the center axis direction. Figures 3 to 5 In the example shown, the sub-shells 6a and 6b are formed by splitting the cylinder in half along the central axis. However, the number and form of the sub-shells 6a and 6b constituting the split core housing 60 are not particularly limited. Each sub-shell 6a and 6b houses a split piece 1a or 1b of the anti-noise ring magnet 100.

[0078] like Figures 3 to 5 As shown in the example, the sub-shells 6a and 6b can also be composed of a dual structure of an inner shell 3 and an outer shell 4. The inner shell 3 has an inner wall portion that protects the inner peripheral hole of the anti-noise annular magnet 100. The outer shell 4 has: an outer wall portion that protects the outer peripheral portion of the anti-noise annular magnet 100; a bottom plate portion that protects the bottom portion; and an upper plate portion that has the function of protecting the upper surface portion. Moreover, the sub-shells 6a and 6b can be connected by a hinge portion. Figures 3 to 5 In the example shown in FIG. 1 , each split piece 1a, 1b is fixed to the inner housing 3 with a double-sided adhesive tape 2 made of acrylic foam having cushioning properties. The inner housing 3 is inserted into the outer housing 4. The split surfaces 10a, 10b of the split pieces 1a, 1b are exposed, and the outer housing is opened, which is the open state before the cable is attached.

[0079] When the split core shell 60 is closed, the split surfaces 10a and 10b of the split pieces 1a and 1b abut against each other inside the split core shell 60 to form the above-mentioned annular anti-noise annular magnet 100. At this time, the surface pressure applied to the split surfaces 10a and 10b is preferably 0.05 MPa or more. As described above, a particularly excellent noise reduction effect can be obtained by pressing the split surfaces 10a and 10b with an appropriate load of 0.05 MPa or more. When the split core shell 60 is closed, the surface pressure applied to the split surfaces 10a and 10b is more preferably 0.10 MPa or more. There is no particular upper limit to the surface pressure applied to the split surfaces 10a and 10b when the split core shell 60 is closed, but in order to effectively prevent deformation and damage to the split surfaces 10a and 10b caused by excessive load, it is preferably 5.0 MPa or less.

[0080] When the split core case 60 is closed, the surface pressure applied to the split surfaces 10a and 10b of the split pieces 1a and 1b is measured as follows. The split core case 60 is folded in half around the hinge and closed. A Fujifilm pressure measuring film is placed between the split surfaces 10a and 10b of the split pieces 1a and 1b, bringing them into contact. With the split core case 60 closed, the surface pressure is measured for two minutes.

[0081] Since the core housing is a split core housing 60, it is easy to attach and detach the cable. Even when the cable is connected, the split core housing 60 can be attached and detached later. This allows the split core housing 60 to be attached and detached while electronic equipment is in use, allowing for adjustment of noise attenuation.

[0082] The material of the split core housing 60 is not particularly limited. Examples include polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyamide (PA), polyphenylene sulfide (PPS), silicone resins, and silicone-based elastomers. Furthermore, thermoplastics containing glass fiber (GF), carbon fiber (CF), graphite (GP), and the like can be used to enhance strength and heat resistance.

[0083] [Manufacturing method]

[0084] The manufacturing method of the noise-reducing annular magnet 100 of the present invention is not particularly limited. For example, a thin strip of amorphous alloy with a thickness of 5 to 50 μm is obtained from a molten alloy using a single-roll method, etc., and the thin strip of amorphous alloy is wound into a cylindrical shape. The amorphous alloy is then heat-treated at a temperature of 300°C to 700°C for 5 to 20 minutes to obtain an annular magnet composed of an Fe-based nanocrystalline alloy. The annular magnet is cut into non-annular shapes to obtain split pieces 1a and 1b. The cut surfaces of the split pieces 1a and 1b are polished using polishing cloth paper to obtain the noise-reducing annular magnet 100 having split surfaces 10a and 10b with a specified surface roughness.

[0085] Before cutting the annular magnet, the anti-noise annular magnet 100 may be impregnated with resin to improve the compression ring strength. For example, the annular magnet is immersed in a solution obtained by mixing epoxy resin and curing agent in a specified ratio, evacuated to below 0.1 MPa and maintained for about 15 minutes, and then opened to the atmosphere to allow the resin to impregnate the annular magnet. The annular magnet impregnated with resin is placed in the atmosphere at room temperature for about 24 hours to solidify. After the annular magnet impregnated with resin is cut into non-annular shapes according to the above method to obtain split pieces 1a and 1b, the cut surfaces of the split pieces 1a and 1b are polished with polishing cloth paper to obtain an anti-noise annular magnet 100 having split surfaces 10a and 10b with a specified surface roughness.

[0086] After polishing the divided surfaces 10a and 10b, a protective film may be formed on the divided surfaces 10a and 10b using a rust preventative agent or a film sheet. The side surfaces (dividing side surfaces) that are continuous with the divided surfaces 10a and 10b may also be protected using a resin coating or tape. Furthermore, the outer peripheries (ends) of the divided surfaces 10a and 10b may be chamfered.

[0087] Hereinafter, the present invention will be described with reference to Examples, but the present invention is not limited to these Examples.

[0088] Example

[0089] (Examples 1_1 to 7)

[0090] Make as Figure 1 The anti-noise ring magnet shown in the figure. First, a molten alloy containing, by atomic percentage, 1% Cu, 3% Nb, 13.5% Si, and 9% B, with the remainder essentially consisting of Fe, is quenched using a single-roll method to obtain a thin ribbon of Fe-based amorphous alloy with a width of 10 mm and a thickness of 20 μm. This Fe-based amorphous alloy is wound into a cylindrical shape with an outer diameter of 28.5 mm, an inner diameter of 18.0 mm, and a height of 10 mm. The cylindrical Fe-based amorphous alloy is inserted into a heat treatment furnace maintained at 490°C under an argon atmosphere and heat treated for 10 minutes. Then, a ring magnet made of an Fe-based nanocrystalline alloy is produced. The resulting ring magnet is immersed in a solution of epoxy resin and a curing agent mixed in a specified ratio. After evacuating the solution to below 0.1 MPa for 15 minutes, the solution is opened to the atmosphere to allow the resin to impregnate the ring magnet. The resin-impregnated ring magnet is left in the atmosphere at room temperature for 24 hours to solidify. The resin-impregnated ring magnet is Figure 1The ring magnet is split in half radially in the manner shown, forming a semicircular shape. The cross-sections of the ring magnet are polished starting with polishing paper with a mesh size of #400 and gradually decreasing in size. The cross-sections are polished to a 0.5 μm aluminum oxide film in Example 1_1, a 1.0 μm aluminum oxide film in Example 1_2, #2500 in Example 1_3, #2000 in Example 1_4, and #800 in Examples 1_5 to 7, yielding anti-noise ring magnets with a specified surface roughness on the cross-sections.

[0091] The resulting anti-noise ring magnets were evaluated for impedance relative permeability, coercive force, surface roughness (flatness, Ra, Rz), surface pressure applied to the split surfaces, and ring pressure strength using the aforementioned methods. The results are shown in Table 1.

[0092] (Examples 2_1 to 3)

[0093] For a noise suppression ring magnet produced in the same manner as in Examples 1 and 2, the surface pressure applied to the split surfaces of the split pieces was varied, and the impedance relative permeability was measured using the above method. The relationship between the obtained impedance relative permeability and the surface pressure is summarized in Table 2. Regarding the obtained contact area relative to the split surfaces of the noise suppression ring magnet, the colored portion with a pressure of 0.05 MPa or more was treated as the effective cross-sectional area, and a coloring ratio of 50% or more was confirmed.

[0094] (Examples 3_1 to 5)

[0095] To confirm the effect of the resin impregnated into the ring magnet on its impedance relative permeability, ring magnets produced similarly to Example 1_2 were prepared. In Examples 3_1 to 3_4, the impregnation resin was the same epoxy resin as in Example 1_2, and in Example 3_5, the impregnation resin was a one-component acrylic resin. In Examples 3_3 and 3_4, after resin impregnation, the ring magnets were further immersed in epoxy resin. Excess epoxy resin was wiped off, and the ring magnets were left at room temperature for approximately 24 hours to cure. The epoxy resin was then coated on the surface of the ring magnets. After resin impregnation or after further resin coating, ring magnets were produced under the same conditions as in Example 1_2. The ring strength and impedance relative permeability of the produced ring magnets were determined using the aforementioned methods. The results are shown in Table 3.

[0096] (Comparative Examples 1_1 to 7)

[0097] Noise-suppressing ring magnets were produced in the same manner as in Example 1_1, except that the split surfaces were polished to #400 in Comparative Examples 1_1-2, to #220 in Comparative Examples 1_3-4, and not polished in Comparative Example 1_7. The resulting noise-suppressing ring magnets were evaluated for impedance relative permeability, coercivity, surface roughness (flatness, Ra, Rz), surface pressure applied to the split surfaces, and ring pressure strength using the aforementioned methods. The results are shown in Table 1. Furthermore, Comparative Example 1_5 used conventional Mn-Zn ferrite, and Comparative Example 1_6 used conventional Ni-Zn ferrite. The impedance relative permeability, coercivity, surface roughness (flatness, Ra, Rz), surface pressure applied to the split surfaces, and ring pressure strength were evaluated using the aforementioned methods. The results are shown in Table 1.

[0098] (Comparative Examples 2_1-2)

[0099] For the anti-noise ring magnets produced under the same conditions as in Examples 1 and 2, the surface pressure applied to the split surfaces of the split pieces was varied, and the impedance relative permeability, coercive force, and flatness were measured using the above-mentioned methods. The results are shown in Table 2.

[0100] (Comparative Examples 3_1 to 4)

[0101] Ring magnets were produced under the same conditions as in Examples 1-1 to 5, except that a polyester resin was used as the resin impregnation agent. The ring magnets were measured for ring strength, impedance relative permeability, coercive force, and flatness using the aforementioned methods. The results are shown in Table 3.

[0102] [Table 1]

[0103]

[0104] [Table 2]

[0105]

[0106] [Table 3]

[0107]

[0108] As described above, by satisfying the conditions of the present invention, it is possible to produce a noise suppression member having an impedance relative magnetic permeability μrz of 6000 or more at a frequency of 100 kHz.

[0109] Industrial applicability

[0110] This anti-noise component is installed in cables of electronic components, power generation devices, power supply devices, communication equipment, and OA / FA equipment in automobiles, and is particularly effective as an anti-noise ring magnet for suppressing noise generated inside or outside these electronic components and electronic devices and transmitted through the cables.

[0111] Description of Reference Numerals

[0112] 1, 1a, 1b: split slices;

[0113] 10, 10a, 10b: splitting surfaces;

[0114] 100: Ring magnet for noise reduction;

[0115] 200: Anti-noise components;

[0116] 2: Double-sided tape;

[0117] 3: Inner shell;

[0118] 4: outer shell;

[0119] 5: fixture;

[0120] 6a, 6b: sub-shell;

[0121] 60: Split core shell;

[0122] 11: Hollow part.

Claims

1. A ring-shaped magnet for noise suppression, which is used by inserting a cable inside. The anti-noise ring magnet includes radially stacked soft magnetic metal strips containing Fe-based nanocrystalline alloy. The anti-noise annular magnet is composed of a plurality of non-annularly divided pieces, and the divided surfaces of the pieces are abutted against each other to form an annular shape for use. The product FL×Hc of the flatness FL of the split surface and the coercive force Hc of the split piece is 7.0 μm·A / m or less. The arithmetic average roughness Ra and the maximum height roughness Rz of the split surface satisfy Ra≤0.7μm and Rz≤10μm respectively. The pressure ring strength is above 50MPa. The surface pressure applied to the split surface is 0.05 MPa or more. The flatness FL is the sum of the absolute values ​​of the maximum value and the minimum value of the cross-sectional curve measured in accordance with JIS B 0601:2001.

2. The anti-noise annular magnet according to claim 1, wherein: The impedance relative permeability μrz at a frequency of 100 kHz is 6000 or more.

3. A noise-proof member comprising: The anti-noise annular magnet according to claim 1 or 2; and A split-type magnetic core shell is formed by connecting subshells in a manner that can be opened and closed to form a cylindrical shape. The subshells are shaped by dividing the cylinder into non-annular shapes, and each of the subshells contains one of the split pieces of the anti-noise annular magnet. When the split core case is closed, the split surfaces of the split pieces abut against each other inside the split core case to form the anti-noise annular magnet.

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