JP2006005236A - Component for noise countermeasure and its mounting structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a component for noise countermeasure wherein it is unnecessary to separately prepare any component which should be fixed to a signal line and enough attenuation can be obtained to a high frequency band noise. <P>SOLUTION: In a component of almost pillar state for noise countermeasure constituted by engaging two magnetic members 10 of almost half pillar state by engaging means, at least one of mutually facing surfaces out of the magnetic members 10 is constituted by a flexible magnetic substance 12. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a noise countermeasure component using a magnetic material and a mounting structure for attaching the noise countermeasure component to a signal line.

As a noise countermeasure component that is attached to a signal line of an electronic device and removes noise propagating through the signal line, one described in Patent Document 1 is known. This noise countermeasure component is formed by inserting a signal line through a cylindrical magnetic core.
JP 2001-155925 A

  The noise countermeasure component described in Patent Document 1 has the following two problems.

  That is, first, as described in the paragraph “0021” of Patent Document 1, in order to fix the noise countermeasure component to the signal line, fixing means such as an adhesive tape, an adhesive, and a string are separately prepared. It is necessary and installation is complicated. That is, since the signal line is merely inserted through the magnetic core, the noise countermeasure component moves in the extending direction of the signal line as it is. Therefore, it is necessary to fix the noise countermeasure component to the signal line with an adhesive tape or the like.

  Secondly, there is a problem that the effective magnetic path length becomes long and sufficient noise attenuation characteristics cannot be obtained. As described in paragraph “0021” of Patent Document 1, the inner diameter of the magnetic core is made larger than the outer diameter of the signal line in order to pass the signal line through the cylindrical magnetic core. There is a need. The smaller the inner diameter of the magnetic core, the shorter the effective magnetic path length. Therefore, when the inner diameter of the magnetic core is made equal to the outer diameter of the signal line, the effective magnetic path length is the shortest. However, since the inner diameter of the magnetic core needs to be larger than the outer diameter of the signal line as described above, the effective magnetic path length becomes longer and the loss effect is reduced, especially at a high frequency exceeding 100 MHz. There is a problem that noise attenuation characteristics tend to deteriorate in the band. At present, when the signal frequency of electronic equipment is high, noise attenuation characteristics in a band exceeding 100 MHz are important, and conventional noise countermeasure components have not been able to sufficiently achieve noise countermeasures in this band. .

  In order to solve the above problems, a noise countermeasure component according to the present invention is a substantially columnar noise countermeasure component obtained by engaging two substantially half-columnar magnetic members by an engaging means, and the magnetic member Among them, at least a part of the surfaces facing each other is made of a flexible magnetic material.

  Thus, if the flexible magnetic body is attached so that the signal line comes into contact with the flexible magnetic body, the noise countermeasure component is fixed to the signal line by the elasticity of the flexible magnetic body, so there is no need to separately provide a fixing member.

  In the present invention, the “flexible magnetic body” means an elastic magnetic body that can be easily deformed or expanded / contracted by an external force.

  In addition, since the flexible magnetic material is in close contact with the signal line, the effective magnetic path length is shortened, and a sufficient noise attenuation can be obtained even in a high frequency band exceeding 100 MHz.

  Further, in the noise countermeasure component according to the present invention, the magnetic member includes a magnetic core having a substantially semi-columnar shape and grooves formed on the surfaces facing each other, and a flexible member disposed in the groove of the magnetic core. And a magnetic material.

  Thereby, the noise attenuation effect can be obtained by both the magnetic core and the flexible magnetic body.

  More specifically, the noise countermeasure component of the present invention is characterized in that the two magnetic members are each housed in a substantially semi-cylindrical case, and the case is the engaging means.

  In the noise countermeasure component of the present invention, the engaging means is not particularly limited, but the magnetic member is housed in a case, and the case is used as the engaging means, thereby easily engaging the two magnetic members. be able to.

  Furthermore, in the noise countermeasure component according to the present invention, it is preferable that a gap for allowing deformation of the flexible magnetic body is provided in the case.

  As a result, the flexible magnetic body is easily deformed and is easily brought into close contact with the signal line. Moreover, it can prevent that a flexible magnetic body is exposed to the outer side of a case by a deformation | transformation.

  A noise countermeasure component mounting structure according to the present invention is a noise countermeasure component mounting structure for mounting the noise countermeasure component according to any one of claims 1 to 4 to a signal line, A signal line is disposed so as to contact the flexible magnetic body of the magnetic member, and a noise countermeasure component is fixed to the signal line by the elasticity of the flexible magnetic body.

  Thereby, since the noise countermeasure component is fixed to the signal line by the elasticity of the flexible magnetic body, it is not necessary to separately provide a fixing member.

  In addition, since the flexible magnetic material is in close contact with the signal line, the effective magnetic path length is shortened, and a sufficient noise attenuation can be obtained even in a high frequency band exceeding 100 MHz.

  As described above, according to the present invention, since the noise countermeasure component is fixed to the signal line by the elasticity of the flexible magnetic body, there is no need to separately provide a fixing member, and the flexible magnetic body is in close contact with the signal line. As a result, the effective magnetic path length is shortened, and sufficient noise attenuation can be obtained even in a high frequency band exceeding 100 MHz.

  The best mode for carrying out the present invention will be described below with reference to the accompanying drawings.

  FIG. 1 is a perspective view showing a noise countermeasure component and its mounting structure according to the present invention.

  As shown in FIG. 1A, the noise countermeasure component of the present invention includes two semi-cylindrical cases 21 and 22 and a magnetic member 10 accommodated in the cases 21 and 22.

  The cases 21 and 22 are made of synthetic resin or the like, and are connected by a connecting portion 23 provided on one side of the opening. The case 21 is provided with an engaging claw 24, and the case 22 is provided with an engaging claw insertion opening 25.

  The magnetic member 10 includes a magnetic core 11 and a flexible magnetic body 12. The magnetic core 11 is made of, for example, a ferrite sintered body having a relative magnetic permeability of 1000 or more and is accommodated in the cases 21 and 22. A groove having a semicircular cross section is formed along the longitudinal direction at a substantially central portion on the opening side of the magnetic core 11. The flexible magnetic body 12 is made of, for example, a mixture of rubber and ferrite powder, has elasticity, and has a relative magnetic permeability of about 5 to 20. The flexible magnetic body is disposed inside the groove of the ferrite core.

  Here, the signal line 30 is brought into contact with the flexible magnetic body 12 so that the openings of the cases 21 and 22 are aligned with each other, and the engaging claws 24 are inserted into the engaging claw insertion openings 25 to fix the two cases 21 and 22. As a result, a noise countermeasure component can be attached to the signal line 30 as shown in FIG.

  At this time, since the flexible magnetic body 12 is made of a material that can be easily deformed and contracted, it is deformed in accordance with the shape of the signal line 30. Therefore, it is possible to attach a noise countermeasure component to the signal line 30 having various wire diameters. Further, since the force is applied in the direction in which the flexible magnetic body 12 holds down the signal line 30 due to the elasticity of the flexible magnetic body 12, the signal line 30 and the noise countermeasure component are fixed without separately providing a fixing member. Yes.

  Furthermore, since the flexible magnetic body 12 is in close contact with the signal line 30, the effective magnetic path length is shorter than that of a conventional noise countermeasure component in which a certain gap is provided between the magnetic core and the signal line. . In general, since the impedance of the ring core is represented by the following equation (1), the shorter the effective magnetic path length, the larger the R component and the noise attenuation characteristics. In Equation (1), Ae is the effective area, Le is the effective magnetic path length, n is the number of turns, and μ = μ ′ + jμ ″.

  Here, the following experiment was conducted in order to confirm the effect of the present invention.

  As a noise countermeasure component according to Example 1 of the present invention, the magnetic core 11 having an outer diameter of 12 mm, an inner diameter of 5.6 mm, and a length of 20 mm shown in FIG. 2A, an outer diameter of 5.6 mm, an inner diameter of 2 mm, A noise countermeasure component made of a flexible magnetic body 12 having a length of 20 mm was prepared. The relative permeability of the magnetic core 11 is 1600, and the relative permeability of the flexible magnetic body 12 is approximately 5. The reason why the inner diameter of the flexible magnetic body 12 is 2 mm is because the outer diameter of the signal line 30 is assumed to be 2 mm.

  As a comparative example, a noise countermeasure component including a magnetic core 13 having an outer diameter of 12 mm, an inner diameter of 5.6 mm, and a length of 20 mm shown in FIG. 2B was prepared. The relative permeability of the magnetic core 13 is 1600.

  The noise countermeasure parts of Example 1 and the comparative example are provided with synthetic resin cases 21 and 22 as shown in FIG. 1 outside the magnetic cores 11 and 13, respectively. The illustration is omitted.

  Then, the frequency characteristics of the impedance of the noise countermeasure part of Example 1 and the noise countermeasure part of the comparative example were measured. The measurement results are shown in FIG.

  The impedance Z is expressed as Z = R + jωL. And while R is represented by the above-mentioned formula (1), L is represented by the following formula (2).

  In the frequency band of 100 MHz or less, since the ratio of μ ′ to μ is much larger than μ ″, the impedance is smaller in Example 1 using the flexible magnetic material having a low magnetic permeability. Since μ ′ rapidly decreases from above about 100 MHz, the ratio of the L component in the impedance decreases and the ratio of the R component increases, so that the noise countermeasure of the first embodiment with a small effective magnetic path length and a large R Therefore, the value of μ ″ of the magnetic cores 11 and 13 and the flexible magnetic body 12 does not change so much.

  In recent years, the frequency of use of electronic equipment has risen to several tens of MHz. In such cases, the impedance in the tens of MHz band is increased in order to increase the amount of noise attenuation while suppressing signal attenuation. A noise countermeasure component having an impedance frequency characteristic that is small and rapidly increases in impedance from around 100 MHz is suitable.

  Next, a second embodiment of the present invention will be described. FIG. 4 is a perspective view showing the noise countermeasure component of this embodiment. In FIG. 4, the same or corresponding parts as in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted as appropriate.

  The feature of the present embodiment is that the magnetic member 10 is composed of only the flexible magnetic member 12 as shown in FIG. That is, in this embodiment, the magnetic core is not used, and only the flexible magnetic body 12 is accommodated in the cases 21 and 22.

  Then, the signal line 30 is brought into contact with the flexible magnetic body 12 so that the openings of the cases 21 and 22 are aligned with each other, and the engagement claws 24 are inserted into the engagement claw insertion openings 25 to fix the two cases 21 and 22. . Thereby, as shown in FIG.4 (b), the noise countermeasure components can be attached to the signal line 30.

  Here, as a noise countermeasure component according to the present embodiment, a noise countermeasure component made of the flexible magnetic body 12 having an outer diameter of 12.0 mm, an inner diameter of 2.5 mm, and a length of 20 mm as shown in FIG. The frequency characteristics of were measured. The reason why the inner diameter of the flexible magnetic body 12 is 2.5 mm is that the outer diameter of the signal line 30 is assumed to be 2.5 mm. The relative magnetic permeability of the flexible magnetic body 12 is approximately 5.

  As a comparative example, the frequency characteristics of the impedance of the conventional noise countermeasure component described above were also measured.

  The measurement results are shown in FIG. In FIG. 5, the cases 21 and 22 are not shown.

  In FIG. 6, it can be considered that the impedance of Example 2 suddenly increases from around 200 MHz due to resonance of the lead wire used for the measurement, but even if the influence of this resonance is excluded, several hundred MHz to 1000 MHz. In the vicinity of (1 GHz), an impedance equal to or higher than that of the noise countermeasure component of the comparative example can be obtained.

  In addition, in the frequency band of about 100 MHz or less, the noise countermeasure component of Example 2 has an extremely low impedance compared to the noise countermeasure component of the comparative example. Therefore, if the noise countermeasure component of the second embodiment is used in an electronic device that uses a signal having a relatively high frequency of about several tens to 100 MHz, the noise attenuation is suppressed and noise of several hundred MHz or more is suppressed. Attenuation equivalent to or higher than that of conventional noise countermeasure components can be obtained.

  Next, a third embodiment of the present invention will be described. FIG. 7 is a perspective view showing a noise countermeasure component according to the third embodiment of the present invention. 7 that are the same as or correspond to those in FIGS. 1 and 4 are denoted by the same reference numerals, and description thereof will be omitted as appropriate.

  As shown in FIG. 7A, the noise countermeasure component includes cases 21 and 22 and a magnetic member 10 accommodated in the cases 21 and 22. The magnetic member 10 includes a magnetic core 11 and a flexible magnetic body 12 disposed in the groove of the magnetic core 11. In the cases 21 and 22, gaps 26 for allowing deformation of the flexible magnetic body 12 are provided at both ends in the longitudinal direction.

  Then, the signal line 30 is brought into contact with the flexible magnetic body 12 so that the openings of the cases 21 and 22 are aligned with each other, and the engagement claws 24 are inserted into the engagement claw insertion openings 25 to fix the two cases 21 and 22. . As a result, the noise countermeasure component can be attached to the signal line 30 as shown in FIG.

  By providing the gaps 26 in the cases 21 and 22, the flexible magnetic body 12 is easily deformed more flexibly and can be attached to the signal wires 30 having various wire diameters.

  The shape of the gap 30 shown in FIG. 7 is an example, and it is sufficient that the gap 30 is formed in a position and shape that allows deformation of the flexible magnetic body 12.

  Next, a noise countermeasure component according to a fourth embodiment of the present invention will be described. FIG. 8 is a perspective view showing a noise countermeasure component according to the fourth embodiment of the present invention. In FIG. 8, parts that are the same as or correspond to those in FIGS. 1, 4, and 7 are given the same reference numerals, and descriptions thereof will be omitted as appropriate.

  As shown in FIG. 8A, the noise countermeasure component includes two magnetic members 10 and an adhesive tape 27 as an engaging structure for engaging the two magnetic members 10. The magnetic member 10 includes a magnetic core 11 and a flexible magnetic body 12 disposed in the groove of the magnetic core 11. The magnetic core 11 has a semi-cylindrical shape, and a groove is formed along the longitudinal direction substantially at the center.

  The magnetic core 11 is closely attached and fixed so that the surfaces on which the grooves are formed face each other. Here, as shown in FIG. 8B, the two magnetic members 10 are engaged by the adhesive tape 27, but the means for fixing the magnetic member 10 is not limited to the adhesive tape 27. Further, the signal line 30 and the noise countermeasure component are fixed by the elasticity of the flexible magnetic body 12.

  In this way, the noise countermeasure component can be configured without providing a case as in the first to third embodiments.

It is a perspective view which shows the noise countermeasure component which concerns on 1st Example of this invention. It is sectional drawing which shows the noise countermeasure component which concerns on 1st Example of this invention, and the noise countermeasure component of a comparative example. It is a graph which shows the frequency characteristic of the impedance of the noise countermeasure component which concerns on 1st Example of this invention, and the noise countermeasure component of a comparative example. It is a perspective view which shows the noise countermeasure component which concerns on 2nd Example of this invention. It is sectional drawing which shows the noise countermeasure components which concern on 2nd Example of this invention. It is a graph which shows the frequency characteristic of the impedance of the noise countermeasure component which concerns on the 2nd Example of this invention, and the noise countermeasure component of a comparative example. It is a perspective view which shows the noise countermeasure components which concern on the 3rd Example of this invention. It is a perspective view which shows the noise countermeasure components which concern on the 4th Example of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Magnetic member 11, 13 Magnetic body core 12 Flexible magnetic body 21, 22 Case 23 Connection part 24 Engagement claw 25 Engagement claw insertion port 26 Gap 27 Adhesive tape 30 Signal line

Claims (5)

A substantially columnar noise countermeasure part formed by engaging two substantially half-columnar magnetic members by an engaging means,
A noise countermeasure component, wherein at least a part of surfaces facing each other of the magnetic member is made of a flexible magnetic material.   The magnetic member includes a magnetic core having a substantially semi-columnar shape and grooves formed on surfaces facing each other, and a flexible magnetic body disposed in the groove of the magnetic core. Item 1. Noise suppression part according to item 1.   The noise countermeasure component according to claim 1 or 2, wherein the two magnetic members are housed in a substantially semi-cylindrical case, and the case is the engaging means.   The noise countermeasure component according to claim 3, wherein a gap for allowing deformation of the flexible magnetic body is provided inside the case. A noise countermeasure component mounting structure for mounting the noise countermeasure component according to any one of claims 1 to 4 to a signal line,
A noise countermeasure component, wherein a signal line is disposed so as to contact the flexible magnetic body of the magnetic member, and the noise countermeasure component is fixed to the signal line by the elasticity of the flexible magnetic body. Mounting structure.

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