JP6852616B2 - Magnetizing device for magnetic particle flaw detection of long materials - Google Patents

Magnetizing device for magnetic particle flaw detection of long materials Download PDF

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JP6852616B2
JP6852616B2 JP2017150828A JP2017150828A JP6852616B2 JP 6852616 B2 JP6852616 B2 JP 6852616B2 JP 2017150828 A JP2017150828 A JP 2017150828A JP 2017150828 A JP2017150828 A JP 2017150828A JP 6852616 B2 JP6852616 B2 JP 6852616B2
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electrode portion
shaped electrode
axle
magnetic flux
long
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JP2019028026A (en
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祐輝 臼谷
祐輝 臼谷
久登 加藤
久登 加藤
倫生 嶋村
倫生 嶋村
宗男 石田
宗男 石田
伸悟 浅海
伸悟 浅海
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Nippon Steel Corp
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Description

本発明は、鉄道車両用の車軸など、長尺材の磁粉探傷用磁化装置に関する。特に、本発明は、長尺材を磁化した場合の長尺材表面近傍の空間における磁束の磁束密度を過不足無く確保することが可能な磁粉探傷用磁化装置に関する。 The present invention relates to a magnetizing device for magnetic particle flaw detection of a long material such as an axle for a railway vehicle. In particular, the present invention relates to a magnetic particle flaw detection magnetizing device capable of ensuring the magnetic flux density of magnetic flux in a space near the surface of a long material when the long material is magnetized without excess or deficiency.

従来、鉄道車両用の車軸の品質保証技術として、磁粉探傷法が広く適用されている。磁粉探傷法では、車軸等の被探傷材を磁化し、蛍光特性を有する磁粉を分散させた磁粉液を被探傷材に散布するのが一般的である。そして、被探傷材に存在する欠陥から外部に漏れ出る漏洩磁束によって凝集した磁粉に紫外線を照射して蛍光発光させ、得られた磁粉模様を目視又は撮像手段で観察することで欠陥を検出する。 Conventionally, the magnetic particle inspection method has been widely applied as a quality assurance technique for axles for railway vehicles. In the magnetic particle inspection method, it is common to magnetize a material to be inspected such as an axle and spray a magnetic powder liquid in which magnetic powder having a fluorescent characteristic is dispersed on the material to be inspected. Then, the magnetic powder aggregated by the leakage magnetic flux leaking from the defect existing in the scratched material is irradiated with ultraviolet rays to emit fluorescence, and the obtained magnetic powder pattern is visually observed or observed by an imaging means to detect the defect.

被探傷材が車軸等の長尺材である場合の磁化方法としては、長尺材の長手方向端部に一対の電極を圧接し、これら一対の電極を介して長尺材の長手方向(軸方向)に直接電流を通電する軸通電法(例えば、特許文献1、2参照)が知られている。軸通電法によれば、長尺材の長手方向周り(周方向)に延びる磁束が形成される。このため、軸通電法は、形成される磁束に直交する方向に延びる欠陥、すなわち、長尺材の長手方向に延びる欠陥の検出に有効である。
また、被探傷材が車軸等の長尺材である場合の磁化方法として、長尺材をコイルに挿通し、該コイルに電流を通電するコイル法も知られている。コイル法によれば、長尺材の長手方向に延びる磁束が形成される。このため、コイル法は、形成される磁束に直交する方向に延びる欠陥、すなわち、長尺材の周方向に延びる欠陥の検出に有効である。
さらに、長尺材の長手方向に延びる欠陥及び周方向に延びる欠陥の双方を検出するため、軸通電法及びコイル法の双方を適用する場合もある(例えば、特許文献3参照)。
なお、磁化方法として軸通電法やコイル法を適用する場合において、検出対象が長尺材の表面近傍の欠陥である場合には、表皮効果が得られるように、通電する電流としては交流電流が用いられる。
When the material to be detected is a long material such as an axle, a pair of electrodes are pressed against the longitudinal end of the long material, and the long material is longitudinally (axis) through the pair of electrodes. A shaft energization method (see, for example, Patent Documents 1 and 2) in which a current is directly energized in a direction) is known. According to the axial energization method, a magnetic flux extending in the longitudinal direction (circumferential direction) of the long member is formed. Therefore, the axial energization method is effective in detecting defects extending in the direction orthogonal to the formed magnetic flux, that is, defects extending in the longitudinal direction of the long member.
Further, as a magnetization method when the material to be detected is a long material such as an axle, a coil method is also known in which a long material is inserted into a coil and an electric current is applied to the coil. According to the coil method, a magnetic flux extending in the longitudinal direction of the long member is formed. Therefore, the coil method is effective in detecting defects extending in the direction orthogonal to the formed magnetic flux, that is, defects extending in the circumferential direction of the long member.
Further, in order to detect both a defect extending in the longitudinal direction and a defect extending in the circumferential direction of the long material, both the axial energization method and the coil method may be applied (see, for example, Patent Document 3).
When the axial energization method or the coil method is applied as the magnetization method, if the detection target is a defect near the surface of a long material, an alternating current is used as the energizing current so that the skin effect can be obtained. Used.

従来、交流電流を用いた軸通電法及びコイル法の双方を適用して車軸を磁化し、磁粉探傷する場合、JISで規定されているA型標準試験片(A1円形)を用いた評価では、明瞭な磁粉模様を観察可能であることが分かっている。換言すれば、従来の磁化方法を用いた磁粉探傷であっても、国内の規格を満足することができ、探傷性能の点で特に問題はないと考えられる。 Conventionally, when the axle is magnetized by applying both the shaft energization method using alternating current and the coil method to detect magnetic particles, the evaluation using the A type standard test piece (A1 circle) specified by JIS is performed. It is known that a clear magnetic particle pattern can be observed. In other words, even magnetic particle flaw detection using the conventional magnetization method can satisfy domestic standards, and it is considered that there is no particular problem in terms of flaw detection performance.

しかしながら、欧州においては、鉄道車両用の車軸の製造規格として、BN918277や、EN13261などが存在する。BN918277においては、磁化中の車軸の表面近傍の空間における磁束密度が2.5mT〜8.2mTの範囲内であることが要求されている。また、EN13261においては、磁化中の車軸の表面近傍の空間における磁束密度が4.0mT以上であることが要求されている。これら欧州の規格は、実際に明瞭な磁粉模様を観察可能であるか否かを重要視する国内規格とは考え方を相違するものである。
本発明者らが検討したところ、従来の磁化方法では、磁化中の車軸の表面近傍の空間における磁束密度が、上記の欧州の規格の上限値・下限値をそれぞれ超える部位が存在し、従来の磁化装置のパラメータ(磁化電流等)を調整するだけでは、上記の欧州の規格を満足し難いことが分かった。
However, in Europe, there are BN918277, EN13261, and the like as manufacturing standards for axles for railway vehicles. In BN918277, the magnetic flux density in the space near the surface of the axle during magnetization is required to be in the range of 2.5 mT to 8.2 mT. Further, in EN 13261, the magnetic flux density in the space near the surface of the axle during magnetization is required to be 4.0 mT or more. These European standards are different from the domestic standards, which emphasize whether or not a clear magnetic particle pattern can actually be observed.
As a result of the examination by the present inventors, in the conventional magnetization method, there are parts where the magnetic flux density in the space near the surface of the axle during magnetization exceeds the upper limit value and the lower limit value of the above European standard, respectively, and there is a conventional part. It was found that it is difficult to satisfy the above European standards simply by adjusting the parameters of the magnetization device (magnetization current, etc.).

実開昭59−180668号公報Jikkai Sho 59-180668 実開昭60−54956号公報Jitsukaisho 60-54956 Gazette 特開平5−164744号公報Japanese Unexamined Patent Publication No. 5-164744

本発明は、上記のような従来技術の問題点を解決するためになされたものであり、鉄道車両用の車軸など、長尺材を磁化した場合の長尺材表面近傍の空間における磁束の磁束密度を過不足無く確保することが可能な磁粉探傷用磁化装置を提供することを課題とする。 The present invention has been made to solve the above-mentioned problems of the prior art, and is a magnetic flux of magnetic flux in a space near the surface of a long material when a long material is magnetized, such as an axle for a railroad vehicle. An object of the present invention is to provide a magnetizing device for magnetic flux flaw detection, which can secure the density in just proportion.

前記課題を解決するため、本発明者らは鋭意検討した結果、従来の交流電流を用いた軸通電法及びコイル法の双方を適用する磁化装置において、前述した欧州の規格を満足しない(下限値を下回る)のは、軸通電法に用いる電極の影響によって、コイル法で形成される磁束の磁束密度が長尺材の端部で低下することが主たる原因であることを見出した。
そして、本発明者らは更に鋭意検討した結果、軸通電法に用いる電極の構造を改良することで、コイル法で形成される磁束の磁束密度の長尺材の端部での低下を抑制できることを見出した。
本発明は、上記の本発明者らの新しい知見に基づき完成したものである。
As a result of diligent studies in order to solve the above-mentioned problems, the present inventors do not satisfy the above-mentioned European standard in the magnetization device to which both the conventional shaft energization method using alternating current and the coil method are applied (lower limit value). It was found that the main reason for this is that the magnetic flux density of the magnetic flux formed by the coil method decreases at the end of the long material due to the influence of the electrodes used in the axial energization method.
As a result of further diligent studies, the present inventors can suppress a decrease in the magnetic flux density of the magnetic flux formed by the coil method at the end of the long material by improving the structure of the electrode used in the axial energization method. I found.
The present invention has been completed based on the above-mentioned new findings of the present inventors.

すなわち、前記課題を解決するため、本発明は、長尺材の長手方向端部にそれぞれ圧接し、前記長尺材の長手方向に交流電流を通電する一対の電極と、前記長尺材を挿通し、交流電流が通電されるコイルと、前記一対の各電極に対して前記長尺材の長手方向端部と反対側にそれぞれ配置された一対の継鉄部材とを備え、前記一対の各電極には、前記長尺材の長手方向に沿って貫通する切欠き部が設けられている、ことを特徴とする長尺材の磁粉探傷用磁化装置を提供する。 That is, in order to solve the above-mentioned problems, in the present invention, a pair of electrodes that are pressure-welded to the longitudinal end portions of the long member and apply an alternating current in the longitudinal direction of the long member and the long member are inserted. A coil to which an alternating current is applied and a pair of joint iron members arranged on the opposite sides of the long member in the longitudinal direction with respect to the pair of electrodes are provided, and the pair of electrodes are provided. Provided is a magnetizing device for magnetic powder flaw detection of a long material, which is provided with a notch portion penetrating along the longitudinal direction of the long material.

本発明によれば、長手方向端部にそれぞれ圧接する一対の電極から長尺材の長手方向に交流電流を通電することで軸通電法が実行され、長尺材を挿通するコイルに交流電流を通電することでコイル法が実行されることになる。
そして、本発明によれば、一対の各電極に対して長尺材の長手方向端部と反対側にそれぞれ配置された一対の継鉄部材を備えるため、コイル法で形成される磁束の磁路を継鉄部材に向けることができる。換言すれば、長尺材の長手方向端部であっても、コイル法で形成される磁束の磁路を長尺材の長手方向に延ばすことができる。
また、本発明によれば、一対の各電極には、長尺材の長手方向に沿って貫通する切欠き部が設けられている。軸通電法を実行するための電極は、一般的に、銅等の導電性材料から形成される。この導電性材料からなる電極にコイル法で形成される磁束(交流磁束)が作用すると、電極に渦電流(長尺材の周方向に流れる渦電流)が生成され、この渦電流によってコイル法で形成される磁束をシールドする効果が生じてしまう。本発明によれば、上記のように各電極に切欠き部が設けられているため、渦電流の経路が妨げられることで、渦電流によるシールド効果が低減すると考えられる。この結果、長尺材の長手方向端部であっても、コイル法で形成される磁束の磁束密度の低下を抑制可能である。
以上のように、本発明によれば、長尺材をコイル法で磁化した場合に形成される磁束の磁束密度の低下を抑制可能であり、その結果、長尺材表面近傍の空間における磁束の磁束密度を過不足無く確保することが可能である。
According to the present invention, the axial energization method is executed by energizing an alternating current in the longitudinal direction of a long material from a pair of electrodes that are in pressure contact with each end in the longitudinal direction, and an alternating current is applied to a coil through which the long material is inserted. The coil method is executed by energizing.
Further, according to the present invention, since each pair of electrodes is provided with a pair of joint iron members arranged on the opposite side of the long member in the longitudinal direction, the magnetic path of the magnetic flux formed by the coil method is provided. Can be directed to the joint iron member. In other words, even at the longitudinal end of the long member, the magnetic path of the magnetic flux formed by the coil method can be extended in the longitudinal direction of the long member.
Further, according to the present invention, each pair of electrodes is provided with a notch portion penetrating along the longitudinal direction of the long member. Electrodes for performing the axial conduction method are generally formed of a conductive material such as copper. When a magnetic flux (AC magnetic flux) formed by the coil method acts on an electrode made of this conductive material, an eddy current (eddy current flowing in the circumferential direction of a long material) is generated on the electrode, and this eddy current causes the coil method. The effect of shielding the formed magnetic flux occurs. According to the present invention, since each electrode is provided with a notch as described above, it is considered that the shielding effect due to the eddy current is reduced by obstructing the path of the eddy current. As a result, it is possible to suppress a decrease in the magnetic flux density of the magnetic flux formed by the coil method even at the end portion in the longitudinal direction of the long material.
As described above, according to the present invention, it is possible to suppress a decrease in the magnetic flux density of the magnetic flux formed when the long material is magnetized by the coil method, and as a result, the magnetic flux in the space near the surface of the long material can be suppressed. It is possible to secure the magnetic flux density in just proportion.

好ましくは、前記一対の各電極は、前記長尺材の長手方向端部に圧接する可撓性電極部と、前記可撓性電極部に対して前記長尺材の長手方向端部と反対側において、前記可撓性電極部に接続された板状電極部と、前記板状電極部に対して前記長尺材の長手方向端部と反対側において、前記板状電極部の略中心に接続され、前記長尺材の長手方向に沿って延びる棒状電極部とを具備し、前記長尺材の長手方向に直交する方向の断面において、前記棒状電極部の寸法は、前記板状電極部の寸法よりも小さく、前記切欠き部は、前記可撓性電極部及び前記板状電極部の双方を貫通する。 Preferably, each of the pair of electrodes has a flexible electrode portion that is in pressure contact with the longitudinal end portion of the long material and a side opposite to the longitudinal end portion of the long material with respect to the flexible electrode portion. In the above, the plate-shaped electrode portion connected to the flexible electrode portion and the plate-shaped electrode portion connected to the substantially center of the plate-shaped electrode portion on the side opposite to the longitudinal end portion of the long member. The rod-shaped electrode portion is provided with a rod-shaped electrode portion extending along the longitudinal direction of the long member, and the dimension of the rod-shaped electrode portion is the dimension of the plate-shaped electrode portion in a cross section in a direction orthogonal to the longitudinal direction of the long member. Smaller than the size, the notch penetrates both the flexible electrode portion and the plate-shaped electrode portion.

上記の好ましい構成によれば、各電極が具備する板状電極部の中心と長尺材の長手方向端部の中心とを略一致させた状態で可撓性電極部を長尺材の長手方向端部に圧接することにより、棒状電極部が長尺材の長手方向端部の略中心に位置することになる。この状態で、棒状電極部から、板状電極部及び可撓性電極部を順に介して長尺材に交流電流を通電することで、長尺材の長手方向端部において周方向に比較的均一な(長手方向端部の中心に対して軸対称に分布する)交流電流が通電されることが期待できる。
また、各電極が具備する棒状電極部の寸法が板状電極部の寸法よりも小さい(棒状電極部の曲げ剛性が板状電極部の曲げ剛性よりも小さい)ため、各電極を長尺材の長手方向端部に圧接する際に、棒状電極部が長尺材の長手方向端部の端面形状や向きに応じて曲げ変形することで、可撓性電極部が長尺材の端部の端面全体に均一に圧接することが期待できる。
以上の結果、上記の好ましい構成によれば、軸通電法によって形成される長尺材の周方向に延びる磁束の磁束密度の大きさを、長尺材の周方向の各部位において比較的均一にすることが可能である。
According to the above preferred configuration, the flexible electrode portion is placed in the longitudinal direction of the long member in a state where the center of the plate-shaped electrode portion included in each electrode and the center of the end portion in the longitudinal direction of the long member are substantially aligned with each other. By pressure contacting the end portion, the rod-shaped electrode portion is located substantially at the center of the longitudinal end portion of the long member. In this state, by applying an alternating current from the rod-shaped electrode portion to the long material through the plate-shaped electrode portion and the flexible electrode portion in order, the long material is relatively uniform in the circumferential direction at the longitudinal end portion. It can be expected that an alternating current (distributed axially symmetrically with respect to the center of the end in the longitudinal direction) is energized.
Further, since the size of the rod-shaped electrode portion provided by each electrode is smaller than the size of the plate-shaped electrode portion (the bending rigidity of the rod-shaped electrode portion is smaller than the bending rigidity of the plate-shaped electrode portion), each electrode is made of a long material. When the rod-shaped electrode portion is pressed against the longitudinal end portion, the rod-shaped electrode portion is bent and deformed according to the end face shape and orientation of the longitudinal end portion of the long material, so that the flexible electrode portion is the end face of the end portion of the long material. It can be expected that the entire surface will be pressed evenly.
As a result of the above, according to the above-mentioned preferable configuration, the magnitude of the magnetic flux density of the magnetic flux extending in the circumferential direction of the long member formed by the axial energization method is relatively uniform in each part in the circumferential direction of the long member. It is possible to do.

本発明によれば、長尺材を磁化した場合の長尺材表面近傍の空間における磁束の磁束密度を過不足無く確保することが可能である。このため、例えば、鉄道車両用の車軸に適用した場合には、欧州における規格であるBN918277やEN13261を満足させることが可能となる。 According to the present invention, it is possible to secure the magnetic flux density of the magnetic flux in the space near the surface of the long material without excess or deficiency when the long material is magnetized. Therefore, for example, when applied to an axle for a railway vehicle, it is possible to satisfy the European standards BN918277 and EN13261.

本発明の一実施形態に係る磁粉探傷用磁化装置を用いて車軸を磁化している状態を概略的に示す平面図である。It is a top view which shows roughly the state which magnetized the axle by using the magnetizing apparatus for magnetic particle flaw detection which concerns on one Embodiment of this invention. 図1に示す一方の電極の具体的な構成を示す図である。It is a figure which shows the specific structure of one electrode shown in FIG. 図1に示す磁化装置を用いた評価試験の結果を示すグラフである。It is a graph which shows the result of the evaluation test using the magnetization device shown in FIG.

以下、添付図面を参照しつつ、本発明の一実施形態について、長尺材が鉄道車両用の車軸である場合を例に挙げて説明する。
図1は、本発明の一実施形態に係る磁粉探傷用磁化装置を用いて車軸を磁化している状態を概略的に示す平面図である。図2は、図1に示す一方の電極の具体的な構成を示す図であり、図2(a)は平面図を、図2(b)は図2(a)の矢符Aの方向から見た図を、図2(c)は図2(a)の矢符Bの方向から見た図を示す。なお、図1では、一対の継鉄部材の図示を省略している。また、図2では、一方の電極1aについて図示しているが、他方の電極1bも同様の構成である。
図1又は図2に示すように、本実施形態に係る磁粉探傷用磁化装置(以下、適宜、単に「磁化装置」ともいう)100は、一対の電極1(1a,1b)と、コイル2(2a,2b,2c,2d,2e)と、一対の継鉄部材3とを備えている。また、本実施形態に係る磁化装置100は、電極1に接続された電源装置4と、コイル2に接続された電源装置5(5a,5b,5c)とを更に備えている。
Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings, taking as an example a case where the long material is an axle for a railway vehicle.
FIG. 1 is a plan view schematically showing a state in which an axle is magnetized using the magnetic particle flaw detection magnetizing device according to the embodiment of the present invention. 2A and 2B are views showing a specific configuration of one of the electrodes shown in FIG. 1, FIG. 2A is a plan view, and FIG. 2B is from the direction of the arrow A in FIG. 2A. 2 (c) shows a view seen from the direction of the arrow B in FIG. 2 (a). In FIG. 1, the illustration of the pair of joint iron members is omitted. Further, although FIG. 2 shows one electrode 1a, the other electrode 1b has the same configuration.
As shown in FIG. 1 or 2, the magnetic particle flaw detection magnetizing device (hereinafter, also appropriately simply referred to as “magnetizing device”) 100 according to the present embodiment includes a pair of electrodes 1 (1a, 1b) and a coil 2 (hereinafter, appropriately referred to as “magnetizing device”). 2a, 2b, 2c, 2d, 2e) and a pair of joint iron members 3. Further, the magnetization device 100 according to the present embodiment further includes a power supply device 4 connected to the electrode 1 and a power supply device 5 (5a, 5b, 5c) connected to the coil 2.

図1に示すように、一対の電極1は、車軸Sの長手方向(軸方向)端部にそれぞれ圧接し、車軸Sの長手方向に交流電流を通電する。具体的には、電極1aは車軸Sの一方の端部の端面に圧接し、電極1bは車軸Sの他方の端部の端面に圧接する。電極1a,1bは、電源装置4に接続されており、電源装置4から交流電流が供給されることで、電極1a,1bを介して車軸Sの長手方向に交流電流が通電する。これにより、磁化方法として軸通電法が実行され、車軸Sの周方向に延びる磁束が形成される。 As shown in FIG. 1, the pair of electrodes 1 are in pressure contact with each end of the axle S in the longitudinal direction (axial direction), and an alternating current is applied in the longitudinal direction of the axle S. Specifically, the electrode 1a is in pressure contact with the end face of one end of the axle S, and the electrode 1b is in pressure contact with the end face of the other end of the axle S. The electrodes 1a and 1b are connected to the power supply device 4, and when the alternating current is supplied from the power supply device 4, the alternating current is energized in the longitudinal direction of the axle S via the electrodes 1a and 1b. As a result, the axial energization method is executed as the magnetization method, and a magnetic flux extending in the circumferential direction of the axle S is formed.

図2に示すように、各電極1a,1b(図2では、前述のように電極1aのみを図示)は、車軸Sの長手方向端部に圧接する可撓性電極部11と、可撓性電極部11に対して車軸Sの長手方向端部と反対側(図2(a)の左側)において、可撓性電極部11に接続された板状電極部12と、板状電極部12に対して車軸Sの長手方向端部と反対側において、板状電極部12の略中心に接続され、車軸Sの長手方向に沿って延びる棒状電極部13とを具備する。
可撓性電極部11としては、例えば断面矩形の銅網電極が用いられる。板状電極部12としては、例えば断面矩形の銅板が用いられる。棒状電極部13としては、例えば断面円形の銅棒が用いられる。車軸Sの長手方向に直交する方向の断面において(図2(c)に示すように、車軸Sの長手方向から見て)、棒状電極部13の寸法(外径)は、板状電極部12の寸法(縦横の長さ)よりも小さくなっている。
なお、本実施形態の各電極1a,1bは、棒状電極部13に接続された銅製等の電極部材14と、電極部材14及び電源装置4に接続された銅製等の電極部材15とを更に具備する。
As shown in FIG. 2, the electrodes 1a and 1b (in FIG. 2, only the electrode 1a is shown as described above) are flexible with the flexible electrode portion 11 that is in pressure contact with the longitudinal end portion of the axle S. On the side opposite to the longitudinal end of the axle S (left side in FIG. 2A) with respect to the electrode portion 11, the plate-shaped electrode portion 12 connected to the flexible electrode portion 11 and the plate-shaped electrode portion 12 On the other hand, on the side opposite to the longitudinal end portion of the axle S, a rod-shaped electrode portion 13 connected to substantially the center of the plate-shaped electrode portion 12 and extending along the longitudinal direction of the axle S is provided.
As the flexible electrode portion 11, for example, a copper mesh electrode having a rectangular cross section is used. As the plate-shaped electrode portion 12, for example, a copper plate having a rectangular cross section is used. As the rod-shaped electrode portion 13, for example, a copper rod having a circular cross section is used. In the cross section in the direction orthogonal to the longitudinal direction of the axle S (as shown in FIG. 2C, when viewed from the longitudinal direction of the axle S), the dimension (outer diameter) of the rod-shaped electrode portion 13 is the plate-shaped electrode portion 12. It is smaller than the dimensions (length and width) of.
Each of the electrodes 1a and 1b of the present embodiment further includes an electrode member 14 made of copper or the like connected to the rod-shaped electrode portion 13, and an electrode member 15 made of copper or the like connected to the electrode member 14 and the power supply device 4. To do.

各電極1a,1bには、車軸Sの長手方向に沿って貫通する切欠き部4が設けられている。具体的には、可撓性電極部11及び板状電極部12の双方を貫通する切欠き部4が設けられている。より具体的には、本実施形態では、板状電極部12に上下方向に延びるスリット状の切欠き部41が4箇所設けられており、各切欠き部41によって区画される3箇所の領域に3分割された可撓性電極部11がそれぞれねじ留め等によって取り付けられている。以上の構成により、可撓性電極部11及び板状電極部12の双方を貫通する切欠き部4が4箇所形成されている。 Each of the electrodes 1a and 1b is provided with a notch 4 penetrating along the longitudinal direction of the axle S. Specifically, a notch portion 4 penetrating both the flexible electrode portion 11 and the plate-shaped electrode portion 12 is provided. More specifically, in the present embodiment, the plate-shaped electrode portion 12 is provided with four slit-shaped notch portions 41 extending in the vertical direction, and the plate-shaped electrode portion 12 is provided with three regions defined by the notch portions 41. The flexible electrode portions 11 divided into three are attached by screwing or the like. With the above configuration, four notches 4 penetrating both the flexible electrode portion 11 and the plate-shaped electrode portion 12 are formed.

図1に示すように、コイル2は、車軸Sを挿通し、交流電流が通電される。具体的には、本実施形態のコイル2としては、車軸Sの一方の端部側に配置されたコイル2a,2bと、車軸Sの中央に配置されたコイル2cと、車軸Sの他方の端部側に配置されたコイル2d,2eとが設けられている。コイル2a,2bは、互いに直列接続され、電源装置5aに接続されている。コイル2cは、電源装置5bに接続されている。コイル2d,2eは、互いに直列接続され、電源装置5cに接続されている。各電源装置5から各コイル2に交流電流が供給されることで、磁化方法としてコイル法が実行され、車軸Sの長手方向に延びる磁束が形成される。 As shown in FIG. 1, the coil 2 is passed through the axle S, and an alternating current is applied. Specifically, as the coil 2 of the present embodiment, the coils 2a and 2b arranged on one end side of the axle S, the coil 2c arranged in the center of the axle S, and the other end of the axle S Coil 2d and 2e arranged on the part side are provided. The coils 2a and 2b are connected in series with each other and are connected to the power supply device 5a. The coil 2c is connected to the power supply device 5b. The coils 2d and 2e are connected in series with each other and are connected to the power supply device 5c. By supplying an alternating current from each power supply device 5 to each coil 2, the coil method is executed as a magnetization method, and a magnetic flux extending in the longitudinal direction of the axle S is formed.

図2に示すように、一対の継鉄部材3(図2では、一方の継鉄部材3のみを図示)は、各電極1a,1bに対して車軸Sの長手方向端部と反対側(図2(a)の左側)にそれぞれ配置されている。具体的には、各継鉄部材3は、各電極1a,1bの板状電極部12から車軸Sの長手方向に一定の間隔を隔てて配置されている。図2(c)に示すように、本実施形態の継鉄部材3は、2分割された継鉄部材片3a,3bから形成されている。継鉄部材片3a,3bは、棒状電極部12(及び電極部材14)を挟んで上下に配置されている。 As shown in FIG. 2, the pair of joint iron members 3 (in FIG. 2, only one joint iron member 3 is shown) is opposite to the longitudinal end of the axle S with respect to the electrodes 1a and 1b (FIG. 2). It is arranged on the left side of 2 (a)). Specifically, the joint iron members 3 are arranged at regular intervals in the longitudinal direction of the axle S from the plate-shaped electrode portions 12 of the electrodes 1a and 1b. As shown in FIG. 2C, the joint iron member 3 of the present embodiment is formed of two divided iron joint member pieces 3a and 3b. The joint iron member pieces 3a and 3b are arranged vertically with the rod-shaped electrode portion 12 (and the electrode member 14) interposed therebetween.

以上に説明した本実施形態に係る磁化装置100によれば、一対の各電極1a,1bに対して車軸Sの長手方向端部と反対側にそれぞれ配置された一対の継鉄部材3を備えるため、コイル法で形成される磁束の磁路を継鉄部材3に向けることができる。換言すれば、車軸Sの長手方向端部であっても、コイル法で形成される磁束の磁路を車軸Sの長手方向に延ばすことができる。
また、本実施形態に係る磁化装置100によれば、一対の各電極1a,1bには、車軸Sの長手方向に沿って可撓性電極部11及び板状電極部12の双方を貫通する切欠き部4が設けられている。このため、各電極1a,1bの可撓性電極部11及び板状電極部12に生成される渦電流の経路が妨げられることで、渦電流によるコイル法で形成される磁束のシールド効果が低減すると考えられる。この結果、車軸Sの長手方向端部であっても、コイル法で形成される磁束の磁束密度の低下を抑制可能である。
以上のように、本実施形態に係る磁化装置100によれば、車軸Sをコイル法で磁化した場合に形成される磁束の磁束密度の低下を抑制可能であり、その結果、車軸Sの表面近傍の空間における磁束の磁束密度を過不足無く確保することが可能である。
According to the magnetizing device 100 according to the present embodiment described above, the pair of joint iron members 3 are provided on the opposite sides of the axle S from the longitudinal end portion to each of the pair of electrodes 1a and 1b. , The magnetic path of the magnetic flux formed by the coil method can be directed to the joint iron member 3. In other words, even at the longitudinal end of the axle S, the magnetic path of the magnetic flux formed by the coil method can be extended in the longitudinal direction of the axle S.
Further, according to the magnetization device 100 according to the present embodiment, the pair of electrodes 1a and 1b are cut so as to penetrate both the flexible electrode portion 11 and the plate-shaped electrode portion 12 along the longitudinal direction of the axle S. A notch 4 is provided. Therefore, the path of the eddy current generated in the flexible electrode portion 11 and the plate-shaped electrode portion 12 of each of the electrodes 1a and 1b is obstructed, so that the shielding effect of the magnetic flux formed by the coil method by the eddy current is reduced. It is thought that. As a result, it is possible to suppress a decrease in the magnetic flux density of the magnetic flux formed by the coil method even at the longitudinal end of the axle S.
As described above, according to the magnetization device 100 according to the present embodiment, it is possible to suppress a decrease in the magnetic flux density of the magnetic flux formed when the axle S is magnetized by the coil method, and as a result, near the surface of the axle S. It is possible to secure the magnetic flux density of the magnetic flux in the space of the above without excess or deficiency.

また、本実施形態に係る磁化装置100によれば、各電極1a,1bが具備する棒状電極部13が板状電極部12の略中心に接続されているため、板状電極部12の中心と車軸Sの長手方向端部の中心とを略一致させた状態で可撓性電極部11を車軸Sの長手方向端部に圧接することにより、棒状電極部13が車軸Sの長手方向端部の略中心に位置することになる。この状態で、電源装置4から、電極部材15、電極部材14、棒状電極部13、板状電極部12及び可撓性電極部11を順に介して車軸Sに交流電流を通電することで、車軸Sの長手方向端部において周方向に比較的均一な(長手方向端部の中心に対して軸対称に分布する)交流電流が通電されることが期待できる。
また、各電極1a,1bが具備する棒状電極部13の寸法が板状電極部12の寸法よりも小さい(棒状電極部13の曲げ剛性が板状電極部12の曲げ剛性よりも小さい)ため、各電極1a,1bを車軸Sの長手方向端部に圧接する際に、棒状電極部13が車軸Sの長手方向端部の端面形状や向きに応じて、例えば図2(a)の矢符Cで示す方向に曲げ変形することで、可撓性電極部11が車軸Sの端部の端面全体に均一に圧接することが期待できる。
以上の結果、本実施形態に係る磁化装置100によれば、軸通電法によって形成される車軸Sの周方向に延びる磁束の磁束密度の大きさを、車軸Sの周方向の各部位において比較的均一にすることが可能である。
Further, according to the magnetizing device 100 according to the present embodiment, since the rod-shaped electrode portion 13 included in each of the electrodes 1a and 1b is connected to the substantially center of the plate-shaped electrode portion 12, it is connected to the center of the plate-shaped electrode portion 12. By pressing the flexible electrode portion 11 against the longitudinal end portion of the axle S in a state where the center of the longitudinal end portion of the axle S is substantially aligned, the rod-shaped electrode portion 13 is brought into contact with the longitudinal end portion of the axle S. It will be located in the center. In this state, an alternating current is applied to the axle S from the power supply device 4 in this order via the electrode member 15, the electrode member 14, the rod-shaped electrode portion 13, the plate-shaped electrode portion 12, and the flexible electrode portion 11, thereby conducting an alternating current on the axle. It can be expected that an alternating current (distributed axially symmetrically with respect to the center of the longitudinal end) is energized at the longitudinal end of S, which is relatively uniform in the circumferential direction.
Further, since the size of the rod-shaped electrode portion 13 included in each of the electrodes 1a and 1b is smaller than the size of the plate-shaped electrode portion 12 (the bending rigidity of the rod-shaped electrode portion 13 is smaller than the bending rigidity of the plate-shaped electrode portion 12). When the electrodes 1a and 1b are pressed against the longitudinal end of the axle S, the rod-shaped electrode portion 13 corresponds to the end face shape and orientation of the longitudinal end of the axle S, for example, the arrow C in FIG. 2A. It can be expected that the flexible electrode portion 11 is uniformly pressed against the entire end surface of the end portion of the axle S by bending and deforming in the direction indicated by.
As a result of the above, according to the magnetization device 100 according to the present embodiment, the magnitude of the magnetic flux density of the magnetic flux extending in the circumferential direction of the axle S formed by the axial energization method is relatively large in each portion of the axle S in the circumferential direction. It can be made uniform.

なお、本実施形態では、長尺材が鉄道車両用の車軸Sである場合を例に挙げて説明したが、本発明はこれに限るものではなく、例えば鋼管やビレットなど、磁性体から形成されている限りにおいて種々の長尺材に適用可能である。 In the present embodiment, the case where the long material is the axle S for a railroad vehicle has been described as an example, but the present invention is not limited to this, and is formed from a magnetic material such as a steel pipe or a billet. As long as it is applicable to various long materials.

以下、本実施形態に係る磁化装置100を用いて、車軸Sに対して軸通電法及びコイル法を同時に実行し、磁化中の車軸Sの表面近傍の空間における磁束の磁束密度を評価した試験結果の一例について説明する。
図1に示すように、一対の電極1a,1bを車軸Sの各端部の端面にそれぞれ圧接し、電源装置4から2900Aの交流電流を供給した。また、車軸Sをコイル2a〜2eに挿通し、電源装置5aからコイル2a,2bに800Aの交流電流を供給し、電源装置5bからコイル2cに500Aの交流電流を供給し、電源装置5cからコイル2d,2eに800Aの交流電流を供給した。コイル2a,2bの合計ターン数は10ターン、コイル2cのターン数は5ターン、コイル2d,2eの合計ターン数は10ターンとした。
以上の条件で車軸Sを磁化し、磁化中の車軸Sの表面近傍の空間における磁束の磁束密度をKARL DEUTSCH社製のドイトロメータを用いて測定した。磁束密度の測定は、車軸Sの長手方向については、図1に示す車軸Sの各長手方向測定位置(a)〜(o)において実施した。車軸Sの周方向については、上部、上部から周方向に90°離れた奥側側面部、−90°離れた手前側側面部の3箇所において磁束密度を測定した。ドイトロメータの向きを直交させて測定することで、車軸Sの周方向に延びる磁束の磁束密度と、車軸Sの長手方向に延びる磁束の磁束密度との双方を測定した。
Hereinafter, using the magnetization device 100 according to the present embodiment, the axial energization method and the coil method are simultaneously executed on the axle S, and the test result of evaluating the magnetic flux density of the magnetic flux in the space near the surface of the axle S during magnetization is evaluated. An example will be described.
As shown in FIG. 1, a pair of electrodes 1a and 1b were pressure-welded to the end faces of each end of the axle S, and an alternating current of 2900 A was supplied from the power supply device 4. Further, the axle S is inserted into the coils 2a to 2e, an alternating current of 800 A is supplied from the power supply device 5a to the coils 2a and 2b, an alternating current of 500 A is supplied from the power supply device 5b to the coil 2c, and the coil is supplied from the power supply device 5c. An alternating current of 800 A was supplied to 2d and 2e. The total number of turns of the coils 2a and 2b was 10, the number of turns of the coil 2c was 5, and the total number of turns of the coils 2d and 2e was 10.
The axle S was magnetized under the above conditions, and the magnetic flux density of the magnetic flux in the space near the surface of the magnetized axle S was measured using a doitrometer manufactured by KARL DEUTSCH. The measurement of the magnetic flux density was carried out in the longitudinal direction of the axle S at the respective longitudinal direction measurement positions (a) to (o) of the axle S shown in FIG. Regarding the circumferential direction of the axle S, the magnetic flux densities were measured at three points: the upper part, the back side surface portion 90 ° away from the upper part in the circumferential direction, and the front side side surface portion −90 ° away. By measuring with the directions of the dytrometer orthogonal to each other, both the magnetic flux density of the magnetic flux extending in the circumferential direction of the axle S and the magnetic flux density of the magnetic flux extending in the longitudinal direction of the axle S were measured.

図3は、上記の評価試験の結果を示すグラフである。図3に示すように、磁化中の車軸Sの表面近傍の空間における磁束の磁束密度は、最大で8.18mTであり、最小で4.07mTであった。すなわち、BN918277の2.5mT〜8.2mT、EN13261の4.0mT以上の何れの規格も満足する結果を得ることが可能であった。
なお、詳細な説明は省略するが、上記の評価試験の条件で、JISで規定されているA型標準試験片を用いた評価も実施したところ、明瞭な磁粉模様を観察可能であった。すなわち、国内の規格も満足することを確認した。
FIG. 3 is a graph showing the results of the above evaluation test. As shown in FIG. 3, the magnetic flux density of the magnetic flux in the space near the surface of the axle S during magnetization was 8.18 mT at the maximum and 4.07 mT at the minimum. That is, it was possible to obtain results satisfying any of the standards of BN918277 of 2.5 mT to 8.2 mT and EN13261 of 4.0 mT or more.
Although detailed description is omitted, when the evaluation using the A type standard test piece specified by JIS was also carried out under the above evaluation test conditions, a clear magnetic particle pattern could be observed. That is, it was confirmed that the domestic standards were also satisfied.

1,1a,1b・・・電極
2,2a,2b,2c,2d,2e・・・コイル
3・・・継鉄部材
4,5,5a,5b,5c・・・電源装置
100・・・磁粉探傷用磁化装置
S・・・車軸(長尺部材)
1,1a, 1b ... Electrodes 2,2a, 2b, 2c, 2d, 2e ... Coil 3 ... Joint iron members 4, 5, 5a, 5b, 5c ... Power supply device 100 ... Magnetic powder Magnetizing device for flaw detection S ... Axle (long member)

Claims (2)

長尺材の長手方向端部にそれぞれ圧接し、前記長尺材の長手方向に交流電流を通電する一対の電極と、
前記長尺材を挿通し、交流電流が通電されるコイルと、
前記一対の各電極に対して前記長尺材の長手方向端部と反対側にそれぞれ配置された一対の継鉄部材とを備え、
前記一対の各電極には、前記長尺材の長手方向に沿って貫通する切欠き部が設けられている、
ことを特徴とする長尺材の磁粉探傷用磁化装置。
A pair of electrodes that are pressure-welded to the longitudinal ends of the long material and apply alternating current in the longitudinal direction of the long material.
A coil through which the long material is inserted and an alternating current is applied,
Each of the pair of electrodes is provided with a pair of joint iron members arranged on the opposite side of the long member in the longitudinal direction.
Each of the pair of electrodes is provided with a notch that penetrates along the longitudinal direction of the long member.
A magnetizing device for magnetic particle flaw detection of long materials.
前記一対の各電極は、
前記長尺材の長手方向端部に圧接する可撓性電極部と、
前記可撓性電極部に対して前記長尺材の長手方向端部と反対側において、前記可撓性電極部に接続された板状電極部と、
前記板状電極部に対して前記長尺材の長手方向端部と反対側において、前記板状電極部の略中心に接続され、前記長尺材の長手方向に沿って延びる棒状電極部とを具備し、
前記長尺材の長手方向に直交する方向の断面において、前記棒状電極部の寸法は、前記板状電極部の寸法よりも小さく、
前記切欠き部は、前記可撓性電極部及び前記板状電極部の双方を貫通する、
ことを特徴とする請求項1に記載の長尺材の磁粉探傷用磁化装置。
Each of the pair of electrodes
A flexible electrode portion that is in pressure contact with the longitudinal end portion of the long material, and a flexible electrode portion.
A plate-shaped electrode portion connected to the flexible electrode portion and a plate-shaped electrode portion connected to the flexible electrode portion on the side opposite to the longitudinal end portion of the long material with respect to the flexible electrode portion.
On the side opposite to the longitudinal end portion of the long member with respect to the plate-shaped electrode portion, a rod-shaped electrode portion connected to substantially the center of the plate-shaped electrode portion and extending along the longitudinal direction of the long member is provided. Equipped with
In the cross section in the direction orthogonal to the longitudinal direction of the long member, the dimension of the rod-shaped electrode portion is smaller than the dimension of the plate-shaped electrode portion.
The notch portion penetrates both the flexible electrode portion and the plate-shaped electrode portion.
The magnetizing device for magnetic particle flaw detection of a long material according to claim 1.
JP2017150828A 2017-08-03 2017-08-03 Magnetizing device for magnetic particle flaw detection of long materials Active JP6852616B2 (en)

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