JP4349481B2 - Magnetic shield structure and magnetic shield method - Google Patents

Description

【００１８】
＜ロ＞磁気シールド材を配置した際の磁場の分布
磁気シールド材２をレール１１から離間して縦方向に配置した合成磁場の強度分布を図４に示す。図４の磁気シールド材２は、部材幅１０ｃｍ、厚さ０．３５ｍｍの珪素鋼板を５０枚重ね合わせたものである。図４の磁気シールド材２は、図５に示すように８０ｃｍの所定間隙（隣接する磁気シールド材の端部間の距離）で６本縦方向に配置され、レールから２ｍ離間してレールに沿って配置されている。磁気シールド材の上下の中心より少し下方位置にレールの水平面が対応している。図４の磁場は、６本の磁気シールド材の左右両端中間位置で、線路に直交する平面上のデータである。図４の磁場強度は、図３と同一の条件で得られたものである。
【００１９】
磁気シールド材２を配置することにより、図４の磁場の強度分布は、図３の磁場の強度分布に比較して、効率よく低減していることが分かる。磁気シールド材２の配置前では、レール１１から３ｍ離れ、高さ１ｍ〜３ｍ付近の磁場の強度は、Ｌ_７の範囲であったが、磁気シールド材２を配置すると、磁場はＬ_３となり、極めて有効に低減していることを示している。また、レール１１から５ｍ付近まで離れた位置で磁場Ｌ_６〜Ｌ_３が磁場Ｌ_３〜Ｌ_２に低減していることを示している。
【００２０】
＜ハ＞間隙を開けて配置した場合の磁場の影響
図５（Ａ）は、図４の左側の線路図を図面の右方から見た磁気シールド材２の配置図である。図５（Ｂ）は、磁場（磁気）の低減率を示したものであり、横軸は、線路に沿った方向（６本の磁気シールド材の配置方向）であり、縦軸は、磁気シールド材２の無い場合に対する低減率（磁場の低減量／磁気シールド材を配置しないときの磁力×１００％）を示している。なお、磁場の低減量＝（磁気シールド材を配置しないときの磁力−磁気シールド材を配置したときの磁力）である。磁気シールド材２は、レールから２ｍ離れ、磁場の測定位置は、レールの水平位置（磁気シールド材２の下端から３２８ｃｍの位置）であり、レールから５ｍ離れた位置である。
【００２１】
図５（Ｂ）のグラフの値は、センター（中心）で低減率１６．７６％、中心から４５ｃｍで１７．２８％、中心から９０ｃｍで１５．９８％、中心から１３５ｃｍで１５．２６％、中心から１８０ｃｍで１３．３１％、中心から２２５ｃｍで１２．０３％、中心から２７０ｃｍで１１．１６％、中心から３１５ｃｍで１０．１７％、中心から３６０ｃｍで７．７６％である。
【００２２】
６本の磁気シールド材の左右両端の中央付近（横軸が０付近）から磁気シールド材２が存在する付近の低減率は１７％〜１２％付近であり、磁気シールド材２から外れても（横軸が２２５ｃｍ以上）、徐々に低減率が低下している。このように、磁気シールド材２の間隙８０ｃｍが、シールド材の部材幅１０ｃｍより８倍も大きく、磁気シールド材２が存在していない場所でも、磁場の低減率が大きいことを示している。この測定結果は、線路の脇を全面に面状の磁気シールド材で覆わなくても、磁場を十分に低減することができることを示している。
【００２３】
＜ニ＞同じ総横幅に磁気シールド材の本数を変化させた場合の磁場の低減率の変化
同じ総横幅（左右両端間の距離）に磁気シールド材の本数を変化させた場合の磁場の低減率の変化を図６に示す。図６は、シールド構造の総横幅が４６０ｃｍの間に磁気シールド材を２〜１６本と変化して配置した際の低減率の変化を示している。測定点は、レールの高さで、レールから５００ｃｍ離れ、磁気シールド材の設置個所の中心である。磁気シールド材の重ね合わせ枚数は５枚で、部材幅は１０ｃｍである。図７は、図６において、磁場の低減に寄与した１本当たりの低減率を示している。図８は、シールド構造の総横幅が４６０ｃｍの間に磁気シールド材の本数を変えて、磁気シールド材の部材間距離（部材中心から部材中心までの中心間距離）に対する低減率の変化を示している。
【００２４】
図６は、同じ総横幅の場合、磁気シールド材の本数が増加するに対応して磁場低減率が増加することを示している。磁気シールド材の本数が６本を越えるとグラフの傾きが緩やかになることを示している。グラフの傾きは磁気シールド材が１本増えることによる磁場低減率の増加分を表しているため、６本を超えると磁気シールド材の本数を増やしても低減率に大きな改善効果が期待できないことが分かる。図７は、磁気シールド材１本当たりが寄与しているその減少率をグラフに示したものであり、磁気シールド材が２〜４本の場合にピークとなり、本数が増加するに従って、低減率が減少していることを示している。図８は、磁気シールド材の設置間隔が狭くなることにより、設置本数が増加するため、設置間隔が狭くなるにつれて、磁場低減率も増加していることが分かる。この実験から、部材幅の２〜９倍の幅で磁気シールド材を配置することにより、２０％程度の磁場低減率が得られることが分かる。
【００２５】
磁場の低減をどの程度にするかは、設置場所の条件など現場のニーズも考慮する必要がある。しかし、図６〜図８の結果からすると、磁気シールド材の設置間隔では、部材幅の２〜９倍の設置間隔において効果的に磁場が低減されているため、この範囲に磁気シールド材を設置することが好ましい。また、１０％程度の低い磁場低減率で十分な設置場所では、磁気シールド材料の費用対効果の最も高い設置個所を条件に応じて設計することができる。
【００２６】
＜ホ＞線路への適用の効果
このように磁気シールド材２の間隙を開けて配置することにより、採光、通風、眺望などの環境を悪化させることなく、しかも、磁場を効率よく低減できる。なお、線路とは、レール１１、き電線１２、トロリ線１３など、車輌を運行するものを言い、主に磁場を発生するものとしては、き電線１２とレール１１がある。
【００２７】
【発明の効果】
本発明は、次のような効果を得ることができる。
＜イ＞本発明は、導電材に流れる電流による磁場を低減することができる。
＜ロ＞また、本発明は、従来のように空間を遮断して採光、通風、眺望などを悪化させることなく、磁場を低減することができる。
＜ハ＞また、本発明は、鉄道沿線に棒状の磁気シールド材を適切に配置して、沿線の磁場を効果的に低減することができる。
【図面の簡単な説明】
【図１】導電材とその周辺に配置した磁気シールド材の配置図
【図２】レールとき電線に流れる電流によって発生する磁場の方向を示す図
【図３】レールとき電線に流れる電流によって発生する磁場の強度を示す図
【図４】間隙を開けて配置された磁気シールド材による磁場の強度を示す図
【図５】磁気シールド材の配置の説明図
【図６】磁気シールド材の本数当たりの磁場低減率を示すグラフの図
【図７】磁気シールド材の１本数当たりの磁場低減率を示すグラフの図
【図８】磁気シールド材の設置間隔当たりの磁場低減率を示すグラフの図
【符号の説明】
１・・・導電材
１１・・レール
１２・・き電線
１３・・トロリ線
２・・・磁気シールド材
３・・・磁場の方向
４・・・柱[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a shield structure that reduces a magnetic field generated by a current flowing through a conductive material such as an electric wire, and more particularly, a shield structure that reduces a magnetic field generated by a current flowing through a power transmission line, a railroad rail, a feeder line, or the like. It is about.
[0002]
[Prior art]
Recently, an external magnetic field has caused the TV to become larger and more susceptible to the effects of color misalignment of the TV and distortion of the screen, and there has been a problem of deterioration in measurement accuracy of electron microscopes and measuring instruments.
[0003]
Cited Document 1 shows that a ferromagnetic layer is provided over the entire surface of the panel to reduce the magnetic field of the line.
[0004]
[Patent Document 1]
Japanese Patent Laid-Open No. 2001-90031
[Problems to be solved by the invention]
<A> The present invention is to reduce a magnetic field caused by a current flowing in a conductive material.
<B> Further, the present invention is to reduce the magnetic field without blocking the space and deteriorating the lighting, ventilation, view and the like as in the prior art.
<C> Further, the present invention is to appropriately dispose a magnetic field along the railway by appropriately arranging a rod-shaped magnetic shield material along the railway.
[0006]
[Means for Solving the Problems]
In order to solve the above problems, the magnetic shield structure of the present invention is a magnetic shield structure that reduces a magnetic field generated by a current flowing in a conductive material. along the conductive material and spaced apart, the magnetic shield material has a member width in the direction along the conductive material, the gap between adjacent magnetic shield material is twice to 9 times of the member width It is characterized by this .
The magnetic shielding method of the present invention is a magnetic shielding method for reducing a magnetic field generated by a current flowing through a conductive material, and a plurality of rod-shaped magnetic shielding materials are spaced from adjacent magnetic shielding materials in the vicinity of reducing the magnetic field. The magnetic shield material has a member width in a direction along the conductive material, and a gap between adjacent magnetic shield materials is 2 to 9 times the member width. .
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below.
[0008]
<A> Magnetic shield structure The magnetic shield structure has a structure in which the magnetic field generated by the current flowing through the conductive material 1 is reduced by the rod-shaped magnetic shield material 2. The magnetic shield structure reduces the magnetic field by arranging a plurality of bar-shaped magnetic shield materials 2 with a gap in the vicinity where the magnetic field is desired to be reduced. In the magnetic shield structure, for example, as shown in FIG. 1, a plurality of rod-shaped magnetic shield materials 2 are installed along the conductive material 1 with gaps (that is, an I-shaped magnetic shield material is attached to the conductive material). They are perpendicular to each other, and a plurality of wires are arranged along the conductive material with a gap between them, and the magnetic field in the vicinity thereof is reduced. By arranging the magnetic shield material 2 with a gap in this way, the magnetic field can be efficiently reduced without blocking the space and deteriorating the environment such as daylighting, ventilation, and view. The conductive material 1 may be any material as long as a current flows and generates a magnetic field around it. The current can be applied as a direct current or an alternating current.
[0009]
<B> Magnetic shield material The magnetic shield material 2 is magnetized by the magnetic field generated by the current flowing in the conductive material 1, and at least reduces the magnetic field by the magnetization. As the magnetic shield material 2, a magnetic material such as a silicon steel plate or permalloy can be used as a material having a high magnetic field reduction effect. The magnetic shield material 2 uses a rod-shaped material. The rod-shaped magnetic shield material 2 is used, for example, by superposing silicon steel plates having a predetermined member width. The bar shape is a member whose width is narrower and longer than the length, and includes a columnar shape and a belt shape, and the cross-sectional shape includes a rectangle, a square, a triangle, a polygon, an ellipse, a circle, and the like. The magnetic shield material 2 can be used in a linear shape or a curved shape as required. The magnetic shield material 2 is covered, surrounded, or supported by a protective material having weather resistance, corrosion resistance, high strength, or the like as necessary.
[0010]
<C> Installation of magnetic shield material The bar-shaped magnetic shield material 2 is arranged with a gap in the vicinity of the magnetic material around the conductive material 1 to reduce the magnetic field. For example, when the rod-shaped magnetic shield material 2 is arranged so as to intersect the conductive material 1 and a plurality of the magnetic shield materials 2 are arranged along the conductive material 1 with a gap therebetween, the magnetic field in a wide area can be efficiently reduced. If the magnetic shield material 2 is disposed at a position where it is easily magnetized, the magnetic field can be further reduced. The magnetic shield material 2 is preferably arranged along the direction of the magnetic force line as much as possible.
[0011]
When the magnetic shield material 2 is a straight line, the magnetic shield material 2 is preferably arranged so as to be in contact with the magnetic field lines where the magnetic field is to be reduced. Further, when the entire magnetic field around the conductive material 1 is reduced, the magnetic shield material 2 may be disposed so as to surround the conductive material 1. For example, the magnetic shield material 2 is disposed along the magnetic force line direction to form a closed loop. Further, when a current flows through the plurality of conductive materials 1 and the combined magnetic field is reduced, the combined magnetic field may be handled in the same manner. For example, when the magnetic shield material 2 is disposed along the direction of the magnetic field lines of the synthesized magnetic field, the reduction effect is enhanced.
[0012]
By incorporating the magnetic shield material 2 into at least a part of the net or lattice and arranging it so as to form the net or lattice, the magnetic shield material 2 can be easily handled and installed. In that case, the magnetic shield material 2 is preferably arranged at a position along the direction of the magnetic field as much as possible.
[0013]
Hereinafter, an embodiment in which the magnetic shield structure is applied to the side of a railway track will be described.
[0014]
<A> Line structure and magnetic field distribution line are provided with rail 11, feeder 12, trolley wire 13 and the like, and FIGS. 2 to 4 show 1/10 scale models. The magnetic field data of the model is shown on the right side of FIGS. The numerical value of the distance described in the drawing is 10 times that of the model and is represented by a value close to the actual value.
[0015]
FIG. 2 shows only the direction 3 of the magnetic field generated near the line when the magnetic shield material 2 is not disposed. FIG. 3 shows the magnetic field of FIG. 2 by intensity distribution, and is a case where the magnetic shielding material 2 is not disposed. The diagram on the right side of FIG. 2 mainly shows a combined magnetic field generated by a direct current that flows in the opposite direction to the electric wire 12 at the same time as the rail 11. FIG. 3 shows the intensity distribution of the synthetic magnetic field. L _{0 to} L ₉ indicate the intensity range of the magnetic field. L ₀ is weak and L ₉ is a strong magnetic field. In FIG. 3, the intensity distribution in the vertical direction at the measurement position 3 m away from the rail 11 in the horizontal direction is strong near the feeder line 12 and becomes weaker as it goes downward. The reason is considered to be that the feeder 12 is closer to the measurement position than the rail 11.
[0016]
In this model, a current of 30 A is passed through the two rails 11 and a current of 24 A is passed through the feeder line 12. However, in an actual line, a current of approximately 2500 A flows through the rail and a current of approximately 2000 A flows through the feeder, so the current is 83 times that of the model. Since the scale of the model is 1/10, the strength of the magnetic field is 8.3 times that of the model. Therefore, the strength of the magnetic field is a value obtained by multiplying the value of the model by 8.3 times and is shown in Table 1.
[0017]
[Table 1]

[0018]
<B> Magnetic Field Distribution When Magnetic Shielding Material is Arranged FIG. 4 shows the intensity distribution of the combined magnetic field in which the magnetic shielding material 2 is spaced apart from the rail 11 and arranged in the vertical direction. The magnetic shield material 2 in FIG. 4 is a stack of 50 silicon steel plates having a member width of 10 cm and a thickness of 0.35 mm. As shown in FIG. 5, six magnetic shield members 2 in FIG. 4 are arranged in the vertical direction with a predetermined gap of 80 cm (distance between the ends of adjacent magnetic shield members), and are separated from the rail by 2 m along the rail. Are arranged. The horizontal plane of the rail corresponds to a position slightly below the center of the top and bottom of the magnetic shield material. The magnetic field in FIG. 4 is data on a plane perpendicular to the line at the middle positions of the left and right ends of the six magnetic shield materials. The magnetic field strength in FIG. 4 is obtained under the same conditions as in FIG.
[0019]
It can be seen that by arranging the magnetic shielding material 2, the magnetic field strength distribution of FIG. 4 is efficiently reduced as compared with the magnetic field strength distribution of FIG. 3. In previous arrangement of the magnetic shield member 2, 3m away from the rail 11, the strength of the magnetic field in the vicinity of the height 1m~3m is ranged of L _7, by placing a magnetic shield member 2, the magnetic field is L _3, and the It shows a very effective reduction. Also it shows that the magnetic field _L. 6 to _{L 3} are reduced to a magnetic field _L 3 ~L ₂ at a distance from the rail 11 to around 5 m.
[0020]
<C> Influence of Magnetic Field when Arranged with a Clearance FIG. 5A is an arrangement diagram of the magnetic shield material 2 when the line diagram on the left side of FIG. 4 is viewed from the right side of the drawing. FIG. 5B shows the reduction rate of the magnetic field (magnetism), the horizontal axis is the direction along the line (the arrangement direction of the six magnetic shield materials), and the vertical axis is the magnetic shield. The reduction rate (the amount of reduction of the magnetic field / the magnetic force when no magnetic shielding material is disposed) with respect to the case without the material 2 is shown. The amount of magnetic field reduction = (magnetic force when no magnetic shield material is arranged−magnetic force when a magnetic shield material is arranged). The magnetic shield material 2 is 2 m away from the rail, and the magnetic field measurement position is the horizontal position of the rail (position 328 cm from the lower end of the magnetic shield material 2), and is a position 5 m away from the rail.
[0021]
The values in the graph of FIG. 5B are 16.76% reduction at the center (center), 17.28% at 45 cm from the center, 15.98% at 90 cm from the center, 15.26% at 135 cm from the center, It is 13.31% at 180 cm from the center, 12.03% at 225 cm from the center, 11.16% at 270 cm from the center, 10.17% at 315 cm from the center, and 7.76% at 360 cm from the center.
[0022]
The reduction rate from the vicinity of the center of the left and right ends of the six magnetic shield materials (the horizontal axis is near 0) to the vicinity where the magnetic shield material 2 is present is about 17% to 12%, and even if it is separated from the magnetic shield material 2 ( The horizontal axis is 225 cm or more), and the reduction rate gradually decreases. Thus, the gap 80 cm of the magnetic shield material 2 is 8 times larger than the member width 10 cm of the shield material, indicating that the magnetic field reduction rate is large even in the place where the magnetic shield material 2 does not exist. This measurement result shows that the magnetic field can be sufficiently reduced without covering the entire side of the line with a planar magnetic shield material.
[0023]
<D> Change in magnetic field reduction rate when the number of magnetic shield materials is changed to the same total horizontal width Magnetic field reduction rate when the number of magnetic shield materials is changed to the same total horizontal width (distance between the left and right ends) FIG. 6 shows the change in the above. FIG. 6 shows a change in the reduction rate when the shield structure is arranged with 2 to 16 magnetic shield materials while the total width of the shield structure is 460 cm. The measurement point is the height of the rail, 500 cm away from the rail, and the center of the installation location of the magnetic shield material. The number of magnetic shield materials to be stacked is 5 and the member width is 10 cm. FIG. 7 shows the reduction rate per line that contributed to the reduction of the magnetic field in FIG. FIG. 8 shows the change in the reduction rate with respect to the distance between members of the magnetic shield material (distance between the centers of the members from the center of the member) by changing the number of magnetic shield materials while the total width of the shield structure is 460 cm. Yes.
[0024]
FIG. 6 shows that for the same total width, the magnetic field reduction rate increases as the number of magnetic shield materials increases. It shows that the slope of the graph becomes gentle when the number of magnetic shield materials exceeds six. Since the slope of the graph represents an increase in the magnetic field reduction rate due to the increase of one magnetic shield material, if the number exceeds 6, even if the number of magnetic shield materials is increased, a large improvement effect cannot be expected in the reduction rate. I understand. FIG. 7 is a graph showing the rate of decrease that one magnetic shield material contributes. When the number of magnetic shield materials is 2 to 4, the rate of decrease increases as the number increases. It shows that it is decreasing. It can be seen from FIG. 8 that the number of installations increases as the installation interval of the magnetic shield material is reduced, so that the magnetic field reduction rate increases as the installation interval is reduced. From this experiment, it is understood that a magnetic field reduction rate of about 20% can be obtained by arranging the magnetic shield material with a width 2 to 9 times the member width.
[0025]
To determine how much the magnetic field is reduced, it is necessary to consider on-site needs such as the conditions of the installation location. However, according to the results of FIGS. 6 to 8, the magnetic shielding material is installed in this range because the magnetic field is effectively reduced in the installation interval of 2 to 9 times the member width in the installation interval of the magnetic shielding material. It is preferable to do. In addition, in a place where a magnetic field reduction rate as low as about 10% is sufficient, the most cost-effective place of magnetic shield material can be designed according to conditions.
[0026]
<Effects of application to the track> Thus, by arranging the magnetic shield material 2 with the gap therebetween, the magnetic field can be efficiently reduced without deteriorating the environment such as daylighting, ventilation, and view. In addition, a track | line means what operates vehicles, such as the rail 11, the feeder 12, and the trolley wire 13, and there exist the feeder 12 and the rail 11 as what mainly generate | occur | produces a magnetic field.
[0027]
【The invention's effect】
The present invention can obtain the following effects.
<A> The present invention can reduce the magnetic field caused by the current flowing through the conductive material.
<B> Further, according to the present invention, the magnetic field can be reduced without blocking the space and deteriorating the daylighting, the ventilation, and the view as in the conventional case.
<C> Further, according to the present invention, it is possible to effectively reduce the magnetic field along the railroad by appropriately arranging a rod-shaped magnetic shield material along the railroad.
[Brief description of the drawings]
[Fig. 1] Arrangement diagram of conductive material and magnetic shield material arranged around it [Fig. 2] Diagram showing direction of magnetic field generated by current flowing in wire when rail [Fig. 3] Generated by current flowing in wire when rail Fig. 4 is a diagram showing the strength of the magnetic field. Fig. 4 is a diagram showing the strength of the magnetic field by the magnetic shield material arranged with a gap. Fig. 5 is an explanatory diagram of the arrangement of the magnetic shield material. Fig. 7 is a graph showing the magnetic field reduction rate. Fig. 7 is a graph showing the magnetic field reduction rate per magnetic shield material. Fig. 8 is a graph showing the magnetic field reduction rate per installation interval of the magnetic shield material. Explanation of]
DESCRIPTION OF SYMBOLS 1 ... Conductive material 11 ... Rail 12 ... Feed wire 13 ... Trolley wire 2 ... Magnetic shielding material 3 ... Magnetic field direction 4 ... Pillar

Claims (9)

In the magnetic shield structure that reduces the magnetic field generated by the current flowing through the conductive material,
A plurality of rod-shaped magnetic shield materials that reduce the magnetic field are arranged at intervals along the conductive material ,
This magnetic shield material has a member width in a direction along the conductive material,
The gap between adjacent magnetic shield materials is 2 to 9 times the width of the member,
Magnetic shield structure. The magnetic shield structure according to claim 1,
The magnetic shield structure is characterized in that the magnetic shield material constitutes at least a part of a net or a lattice. The magnetic shield structure according to claim 1,
The magnetic shield structure is characterized in that the magnetic shield material is disposed substantially orthogonal to the conductive material. The magnetic shield structure according to claim 1,
At least one end portion of the magnetic shield material is disposed in the vicinity where the magnetic shield material near the end portion and the direction of the magnetic field are substantially orthogonal to each other. The magnetic shield structure according to claim 1,
The magnetic shield material is covered with, surrounded by, or supported by a protective material. The magnetic shield structure according to claim 1,
When the conductive material is railroad rails or feeders,
A magnetic shield structure, wherein the magnetic shield material is disposed around the track with a gap along the track. The magnetic shield structure according to claim 1,
If the conductive material is a railroad rail,
A magnetic shield material, wherein the magnetic shield material is arranged in the vertical direction beside the track. The magnetic shield structure according to claim 7 ,
The upper end of the magnetic shield material
A magnetic shield structure, characterized in that the magnetic shield is arranged in the vicinity of a horizontal direction. In a magnetic shielding method for reducing a magnetic field generated by a current flowing in a conductive material,
In the vicinity of reducing the magnetic field, a plurality of rod-shaped magnetic shield materials are arranged with an interval between adjacent magnetic shield materials,
This magnetic shield material has a member width in a direction along the conductive material,
The gap between adjacent magnetic shield materials is 2 to 9 times the width of the member,
Magnetic shield method.

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