JP5465803B2 - Method for adjusting magnetizing device of object to be inspected - Google Patents

Description

  The present invention relates to a method for adjusting a magnetizing apparatus that magnetizes an object to be inspected in a magnetic particle flaw detector.

  As an example of a non-destructive inspection method, a test object is magnetized with a magnetizing device, magnetic powder is dispersed on the magnetized test object, and the damage or cracking of the test object is determined from the distribution state of the magnetic powder adhered to the test object. There are known magnetic particle flaw detection methods for detecting. When magnetizing an object to be inspected with a magnetizing apparatus in such a magnetic particle flaw detection method, the accuracy of detection of the scratch or crack is determined by the angle between the direction of the scratch or crack generated in the object to be inspected and the direction of the magnetic field lines of the magnetic field. Come different. Specifically, in the state where the magnetic lines of force are perpendicular to the longitudinal direction of the scratches and cracks, the leakage magnetic flux generated by the scratches and cracks is the largest, so the magnetic powder pattern formed by the magnetic powders attached to the scratches and cracks is the clearest Can be identified.

  However, it is usually difficult to predict the direction of scratches and cracks occurring in the object to be inspected. Therefore, by magnetizing the object to be inspected using a magnetizing device that generates a multi-directional magnetic field, the object to be inspected is magnetized in a state in which the magnetic lines of force are perpendicular to the scratches and cracks regardless of the direction of the scratches or cracks. It has been conventionally performed to improve the detection accuracy of body scratches and cracks.

For example, by providing an X-axis excitation coil and a Y-axis excitation coil for the object to be inspected, and applying alternating voltages of different frequencies to each other, the combined vector of the X-axis and Y-axis magnetic field lines becomes a circular locus. A magnetizing device for magnetic particle flaw detection that is configured is known (see, for example, Patent Document 1). In addition, a pair of magnetizing coils facing in the X-axis direction, a pair of magnetizing coils facing in the Y-axis direction, and a pair of magnetizing coils facing in the Z-axis direction are provided on the object to be inspected. A magnetic particle flaw detector is known in which the frequency, the excitation frequency of the Y-axis magnetizing coil, and the excitation frequency of the Z-axis magnetizing coil are set to non-integer multiples (see, for example, Patent Document 2).
The X axis, the Y axis, and the Z axis are coordinate axes in the orthogonal coordinate system of the three-dimensional space, the X axis and the Y axis are orthogonal, and the Z axis is orthogonal to both the X axis and the Y axis. It is an axis to do.

JP-A-11-160283 JP 2007-298482 A

  Here, a plane along the X axis and the Y axis is referred to as an “XY plane”, a plane along the Y axis and the Z axis is referred to as a “YZ plane”, and a plane along the Z axis and the X axis is referred to as a “ZX plane”. The same shall apply hereinafter.

  The prior art disclosed in Patent Document 1 can generate a multidirectional magnetic field with respect to the XY plane. However, since the prior art disclosed in Patent Document 1 does not include a means for generating a Z-axis magnetic field, a multi-directional magnetic field can be generated for the YZ plane and the ZX plane. Can not. For this reason, in the conventional technique disclosed in Patent Document 1, there is a possibility that the magnetic particle flaw detection accuracy in the YZ plane and the ZX plane is significantly lowered with respect to a three-dimensional object to be inspected.

  Furthermore, the prior art disclosed in Patent Document 1 requires that a rectifier and an inverter corresponding to a plurality of exciting coils be individually provided between a commercial three-phase AC power source and a magnetizing device. There is a risk of cost increase.

  The prior art disclosed in Patent Document 2 can generate a multidirectional magnetic field in each of the XY plane, the YZ plane, and the ZX plane. However, the prior art disclosed in Patent Document 2 is the same as the prior art disclosed in Patent Document 1, and the three corresponding to each of a plurality of exciting coils between a commercial three-phase AC power source and a magnetizing device. Since it is necessary to provide a set of rectifiers and inverters separately, there is a risk of a significant increase in the cost of the magnetic particle flaw detector.

  Furthermore, since the conventional techniques disclosed in Patent Document 1 and Patent Document 2 are configured to generate a magnetic field only with an air-core exciting coil, in order to generate a magnetic field having a strength necessary for magnetization of an object to be inspected. It is necessary to pass a large current. Therefore, it is often necessary to provide a special power supply device between the commercial three-phase AC power supply and the magnetizing device, which may cause a significant increase in cost of the magnetic particle flaw detector.

  In view of such circumstances, the present invention has been made, and its purpose is to realize magnetic particle flaw detection that can obtain high magnetic particle flaw detection accuracy on the entire surface of the XY plane, the YZ plane, and the ZX plane at a low cost. There is to do.

<First Aspect of the Present Invention>
In the first aspect of the present invention, three magnetizing elements each having a wire wound around a yoke are arranged with a phase difference of 120 degrees from each other, and the wires of the three magnetizing elements are Δ-connected or Y-connected. A first magnetizer, a magnetizing element in which an electric wire is wound around a yoke, a second magnetizer facing the object to be inspected in a direction different from that of the first magnetizer, and a three-phase AC voltage applied to the first magnetizer. And a power supply device that applies an AC voltage to the second magnetizer while applying the AC voltage to the magnetizer.

  The first magnetizer is composed of three magnetizing elements arranged with a phase difference of 120 degrees from each other. Therefore, by applying a three-phase AC voltage to the first magnetizer, it is possible to form a rotating magnetic field in which the strength of the magnetic field is 360 degrees and becomes substantially uniform. Therefore, for example, when the surface facing the first magnetizer is an XY plane, a rotating magnetic field having a magnetic field strength of 360 degrees and substantially uniform can be formed on the XY plane. The second magnetizer faces the object to be inspected in a direction different from that of the first magnetizer to form a magnetic field. Therefore, a rotating magnetic field is also formed in the YZ plane and the ZX plane by a combined vector of the magnetic field formed by the second magnetizer and the rotating magnetic field formed by the first magnetizer in the XY plane. Become. That is, the magnetizing apparatus for an object to be inspected according to the present invention can form an effective rotating magnetic field (a magnetic field in which the direction of the line of magnetic force changes by 360 degrees) on each of the XY plane, the YZ plane, and the ZX plane. Therefore, high magnetic particle flaw detection accuracy can be obtained on the entire surface of the XY plane, the YZ plane, and the ZX plane.

  In addition, since both the first magnetizer and the second magnetizer are configured using a magnetizing element in which an electric wire is wound around a yoke (yoke), the magnetizer is more than a conventional magnetizing element consisting only of an air-core exciting coil. A magnetic field having a desired strength can be formed with a significantly smaller current. Therefore, a commercial three-phase AC power source can be used as it is for the first magnetizer. Further, since the first magnetizer can form a rotating magnetic field alone, it is not necessary to provide a phase difference between the three-phase AC voltage applied to the first magnetizer and the AC voltage applied to the second magnetizer. Therefore, as the AC voltage applied to the second magnetizer, a commercial three-phase AC power source can be used as it is, or a line voltage of any one of the commercial three-phase AC power sources can be used as it is. In other words, the magnetizing apparatus for a device to be inspected according to the present invention can use a commercial three-phase AC power source as it is, so that it is not necessary to provide a rectifier or an inverter as in the prior art, and a special power source for obtaining a large current. It is not necessary to provide a device or the like, and can be realized at an extremely low cost.

  Thus, according to the first aspect of the present invention, a magnetic particle flaw detector capable of obtaining high magnetic particle flaw detection accuracy on the entire surface of the XY plane, the YZ plane, and the ZX plane can be realized with a simple configuration at low cost. The effect is obtained.

<Second Aspect of the Present Invention>
According to a second aspect of the present invention, in the first aspect of the present invention described above, the first magnetizer is characterized in that the three magnetization elements are arranged concentrically. It is a magnetizing device.
According to such a feature, the strength of the magnetic field with respect to the rotational direction of the rotating magnetic field (the rotating magnetic field in the XY plane) formed by the first magnetizer can be made more uniform. The effect of obtaining flaw detection accuracy is obtained.

<Third Aspect of the Present Invention>
According to a third aspect of the present invention, in the first aspect or the second aspect of the present invention described above, the power supply device includes a frequency of a three-phase AC voltage applied to the first magnetizer and the second magnetizer. A magnetizing device for an object to be inspected, characterized in that the frequency of the alternating voltage applied to is different.
According to such a feature, a phase shift occurs according to the frequency ratio between the three-phase AC voltage applied to the first magnetizer and the AC voltage applied to the second magnetizer. Thereby, in the rotating magnetic field (rotating magnetic field in the YZ plane and the ZX plane) by the combined vector of the rotating magnetic field formed by the first magnetizer and the magnetic field formed by the second magnetizer, the magnetic field of the Z-axis direction component Strength can be increased. Therefore, the effect of obtaining higher magnetic particle flaw detection accuracy can be obtained.

<Fourth aspect of the present invention>
According to a fourth aspect of the present invention, in the third aspect of the present invention described above, the power supply device has a frequency of a three-phase AC voltage applied to the first magnetizer and an AC voltage applied to the second magnetizer. This is a magnetizing apparatus for an object to be inspected, which is set to have a non-multiplied frequency.
According to such a feature, an irregular phase shift occurs between the three-phase AC voltage applied to the first magnetizer and the AC voltage applied to the second magnetizer. Thereby, in the rotating magnetic field (rotating magnetic field in the YZ plane and the ZX plane) by the combined vector of the rotating magnetic field formed by the first magnetizer and the magnetic field formed by the second magnetizer, the magnetic field of the Z-axis direction component The strength can be further increased. Therefore, the effect of obtaining higher magnetic particle flaw detection accuracy can be obtained.

<Fifth aspect of the present invention>
According to a fifth aspect of the present invention, in any one of the first to fourth aspects of the present invention described above, the second magnetizer is configured such that three magnetized elements each having a wire wound around a yoke are 120 degrees to each other. The three magnetized elements are arranged in a phase difference of Δ, Y-connected, and the power supply device applies a three-phase AC voltage to the second magnetizer. It is a body magnetizing device.
According to such a feature, in addition to the rotating magnetic field generated by the first magnetizer, a rotating magnetic field different from the rotating magnetic field generated by the first magnetizer is formed by the second magnetizer. Thereby, in the rotating magnetic field (rotating magnetic field of the YZ plane and the ZX plane) of the combined vector of the rotating magnetic field formed by the first magnetizer and the rotating magnetic field formed by the second magnetizer, the Z-axis direction component The magnetic field strength can be further increased. Therefore, the effect of obtaining higher magnetic particle flaw detection accuracy can be obtained.

<Sixth aspect of the present invention>
According to a sixth aspect of the present invention, in the inspected object according to the fifth aspect of the present invention, the second magnetizer includes the three magnetized elements arranged concentrically. It is a magnetizing device.
According to such a feature, the strength of the magnetic field with respect to the rotation direction of the rotating magnetic field formed by the second magnetizer can be made more uniform, so that the effect of obtaining a more stable high magnetic particle flaw detection accuracy can be obtained. can get.

<Seventh aspect of the present invention>
According to a seventh aspect of the present invention, in any one of the first to sixth aspects of the present invention described above, the second magnetizer is disposed so as to face the first magnetizer. This is a magnetizing apparatus for the object to be inspected.
According to such a feature, the combined vector of the rotating magnetic field formed by the first magnetizer and the magnetic field formed by the second magnetizer has more components in the facing direction (Z-axis direction component). Thereby, the magnetic field strength of the Z-axis direction component can be effectively increased in the rotating magnetic field (rotating magnetic field in the YZ plane and ZX plane) by the combined vector. Therefore, the effect of obtaining higher magnetic particle flaw detection accuracy can be obtained.

<Eighth aspect of the present invention>
According to an eighth aspect of the present invention, the device under test is characterized in that, in the seventh aspect of the present invention described above, the first magnetizer and the second magnetizer are arranged at an opposing angle. It is a magnetizing device.
According to such a feature, the magnetic field distribution between the first magnetizer and the second magnetizer is biased. Thereby, in the rotating magnetic field (rotating magnetic field in the YZ plane and the ZX plane) by the combined vector of the rotating magnetic field formed by the first magnetizer and the magnetic field formed by the second magnetizer, the magnetic field of the Z-axis direction component The strength can be further increased. Therefore, the effect of obtaining higher magnetic particle flaw detection accuracy can be obtained.

<Ninth aspect of the present invention>
According to a ninth aspect of the present invention, in the seventh aspect or the eighth aspect of the present invention described above, the first magnetizer and the second magnetizer include the magnetic field center of the first magnetizer and the first magnetizer. A magnetizing apparatus for an object to be inspected, wherein the magnetizing apparatus is arranged so that the magnetic field center of the two magnetizers is shifted in a direction crossing the opposing direction.
According to such a feature, a gradient is generated in the magnetic field distribution between the rotating magnetic field formed by the first magnetizer and the magnetic field formed by the second magnetizer. Thereby, in the rotating magnetic field (rotating magnetic field in the YZ plane and the ZX plane) by the combined vector of the rotating magnetic field formed by the first magnetizer and the magnetic field formed by the second magnetizer, the magnetic field of the Z-axis direction component The strength can be further increased. Therefore, the effect of obtaining higher magnetic particle flaw detection accuracy can be obtained.

<Tenth aspect of the present invention>
According to a tenth aspect of the present invention, in the fifth or sixth aspect described above, the first magnetizer and the second magnetizer include three magnetization elements of the first magnetizer and the second magnetizer. A magnetizing apparatus for an object to be inspected, characterized in that the three magnetizing elements of the magnetizer are arranged to face each other with a phase difference in the rotational direction.
According to such a feature, a phase shift occurs between the rotating magnetic field formed by the first magnetizer and the rotating magnetic field formed by the second magnetizer. Thereby, in the rotating magnetic field (rotating magnetic field of the YZ plane and the ZX plane) of the combined vector of the rotating magnetic field formed by the first magnetizer and the rotating magnetic field formed by the second magnetizer, the Z-axis direction component The magnetic field strength can be further increased. Therefore, an effect of obtaining higher magnetic particle flaw detection accuracy can be obtained.

<Eleventh aspect of the present invention>
According to an eleventh aspect of the present invention, in any one of the first to sixth aspects of the present invention described above, the second magnetizer faces the object to be inspected in a direction different from the first magnetizer by 90 degrees. This is a magnetizing apparatus for an object to be inspected.
According to such a feature, a magnetic field in the Z-axis direction can be directly formed on the ZX plane or the YZ plane by the second magnetizer. Thereby, in the rotating magnetic field (rotating magnetic field in the YZ plane and the ZX plane) by the combined vector of the rotating magnetic field formed by the first magnetizer and the magnetic field formed by the second magnetizer, the magnetic field of the Z-axis direction component The strength can be further increased. Therefore, the effect of obtaining higher magnetic particle flaw detection accuracy can be obtained.

<Twelfth aspect of the present invention>
A twelfth aspect of the present invention is a magnetic particle flaw detector comprising the magnetizing apparatus for an object to be inspected according to any one of the first to eleventh aspects of the present invention described above.
According to the twelfth aspect of the present invention, in the magnetic particle flaw detector, the operational effects of the invention according to any one of the first to eleventh aspects of the present invention described above can be obtained.

<13th aspect of this invention>
In a thirteenth aspect of the present invention, three magnetizing elements each having a wire wound around a yoke are arranged with a phase difference of 120 degrees from each other, and the wires of the three magnetizing elements are Δ-connected or Y-connected. A first magnetizer, a magnetizing element in which a wire is wound around a yoke, a second magnetizer that faces the object to be inspected in a different direction from the first magnetizer, and a three-phase AC voltage to the first magnetizer And a power supply device that applies an AC voltage to the second magnetizer, and a method for adjusting the magnetization device of the device to be inspected, wherein the X axis, the Y axis, and the Z axis in a region where the device to be inspected is installed A first Lissajous waveform based on the strength of the magnetic field on the X axis and the strength of the magnetic field on the Y axis, and the first based on the strength of the magnetic field on the Y axis and the strength of the magnetic field on the Z axis. 2 Lissajous waveform, third resurge due to Z-axis magnetic field strength and X-axis magnetic field strength Any one or more of the waveforms are observed with a waveform observer connected to the magnetometer, and the first magnetizer or the second magnetization is adjusted so that the aspect ratio value of the Lissajous waveform being observed approaches 1. Adjusting the position or orientation of the magnet, and the frequency ratio between the three-phase AC voltage applied to the first magnetizer and the AC voltage applied to the second magnetizer; Is the method.

  From the first Lissajous waveform, a change in the strength of the magnetic field in the rotating direction of the rotating magnetic field in the XY plane can be visually grasped in real time. From the second Lissajous waveform, a change in the strength of the magnetic field in the rotation direction of the rotating magnetic field in the YZ plane can be visually grasped in real time. From the third Lissajous waveform, a change in magnetic field strength in the rotation direction of the rotating magnetic field in the ZX plane can be visually grasped in real time. Then, the closer the aspect ratio value of the Lissajous waveform is to 1 (for example, the closer the Lissajous waveform is to a perfect circle), the more uniform the magnetic field strength is in the rotating direction of the rotating magnetic field. That is, the closer the value of the aspect ratio of the Lissajous waveform is to 1, the higher the magnetic particle flaw detection accuracy by the rotating magnetic field. Therefore, while observing the Lissajous waveform with a magnetometer, the position or orientation of the first magnetizer or the second magnetizer and the three phases applied to the first magnetizer so that the aspect ratio value of the Lissajous waveform approaches 1 By adjusting the frequency ratio between the AC voltage and the AC voltage applied to the second magnetizer, it is possible to adjust the magnetizing device of the object to be inspected so that good magnetic particle flaw detection accuracy can be obtained.

  Thus, according to the thirteenth aspect of the present invention, in the magnetizing apparatus for an object to be inspected as described above, the operation for adjusting to a state in which good magnetic particle flaw detection accuracy is obtained (a good magnetic powder pattern is obtained) is simple and high. The effect of being able to carry out with accuracy is obtained.

  According to the present invention, it is possible to obtain an effect that a magnetic particle flaw detector capable of obtaining high magnetic particle flaw detection accuracy on the entire surface of the XY plane, the YZ plane, and the ZX plane can be realized at a low cost with a simple configuration.

The perspective view of a three pole yoke type | mold magnetizer. The front view of a three pole yoke type magnetizer. Structure and connection diagram of a three-pole yoke type magnetizer. FIG. 6 is a structural diagram and a connection diagram of a modified example of a three-pole yoke magnetizer. The perspective view and structural drawing of a two-pole yoke type magnetizer. The block diagram which illustrated the structure of the magnetization apparatus of the to-be-inspected object of 1st Example. The connection diagram of the magnetization apparatus of the to-be-inspected object of 1st Example. The Lissajous waveform of the magnetic field in the magnetizing apparatus of the device under test of the first embodiment. The connection diagram of the magnetization apparatus of the to-be-inspected object of 2nd Example. The Lissajous waveform of the magnetic field in the magnetizing apparatus of the device under test of the second embodiment. The block diagram which illustrated the structure of the magnetization apparatus of the to-be-inspected object of 3rd Example. The connection diagram of the magnetization apparatus of the to-be-inspected object of 3rd Example. The connection diagram of the magnetization apparatus of the to-be-inspected object of 4th Example. The block diagram which illustrated the structure of the magnetization apparatus of the to-be-inspected object of 5th Example. The connection diagram of the magnetization apparatus of the to-be-inspected object of 5th Example. The connection diagram of the magnetization apparatus of the to-be-inspected object of 6th Example. The front view of the three pole yoke type | mold magnetizer in the magnetizing apparatus of the to-be-inspected object of 7th Example. The block diagram which illustrated the structure of the magnetization apparatus of the to-be-inspected object of 8th Example. The block diagram which illustrated the structure of the magnetization apparatus of the to-be-inspected object of 9th Example.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

<Configuration of three-pole yoke magnetizer>
The configuration of the three-pole yoke magnetizer 10 will be described with reference to FIGS.
FIG. 1 is a perspective view of a three-pole yoke magnetizer 10. FIG. 2 is a front view of the three-pole yoke magnetizer 10. 3 illustrates the configuration of the three-pole yoke magnetizer 10, FIG. 3 (a) is a structural diagram of the three-pole yoke magnetizer 10, and FIG. 3 (b) is a three-pole yoke magnetizer 10. FIG.

  The three-pole yoke magnetizer 10 includes a first magnetizing element 11, a second magnetizing element 12, a third magnetizing element 13, a base 14, and a three-pole yoke 15. The first magnetizing element 11, the second magnetizing element 12, and the third magnetizing element 13 are arranged and fixed on the base 14 with a phase difference of 120 degrees from each other.

The three-pole yoke 15 is a yoke formed by laminating silicon steel plates, and has a first magnetic pole 151, a second magnetic pole 152, and a third magnetic pole 153. An electric wire is wound around the first magnetic pole 151 to constitute a coil L11, and the first magnetic element 151 is constituted by the first magnetic pole 151 and the coil L11. An electric wire is wound around the second magnetic pole 152 to constitute a coil L12, and the second magnetic element 152 and the coil L12 constitute the second magnetizing element 12. An electric wire is wound around the third magnetic pole 153 to constitute a coil L13, and the third magnetic element 153 is constituted by the third magnetic pole 153 and the coil L13.
In order to form a stronger and more uniform magnetic field, it is desirable that the number of turns of the coil L11, the coil L12, and the coil L13 is larger.

  The coil L11, the coil L12, and the coil L13 are Δ-connected. More specifically, the connection point between the coil L11 and the coil L13 is connected to the terminal A1, the connection point between the coil L11 and the coil L12 is connected to the terminal A2, and the connection point between the coil L12 and the coil L13 is the terminal A3. It is connected to the.

  The three-pole yoke magnetizer 10 including the first magnetizing element 11, the second magnetizing element 12, and the third magnetizing element 13 arranged with a phase difference of 120 degrees in this way is connected to the terminals A1 to A3 with a three-phase alternating current. By applying a voltage, it is possible to form a rotating magnetic field in which the strength of the magnetic field is 360 degrees and becomes substantially uniform. The first magnetizing element 11, the second magnetizing element 12, and the third magnetizing element 13 are not essential elements of the present invention, but are preferably arranged on concentric circles. Thereby, when a three-phase AC voltage is applied to the three-pole yoke type magnetizer 10, the magnetic field strength with respect to the rotation direction of the rotating magnetic field formed by the three-pole yoke type magnetizer 10 can be made more uniform.

FIG. 4 illustrates a modification of the three-pole yoke type magnetizer 10. FIG. 4 (a) is a structural diagram of the three-pole yoke type magnetizer 10, and FIG. 4 (b) is a three-pole yoke type magnetizer 10. FIG.
The modification of the three-pole yoke magnetizer 10 has the same configuration as that of the three-pole yoke magnetizer 10 shown in FIGS. 1 to 3 except that the coils L11 to L13 are connected differently. In the modification of the three-pole yoke magnetizer 10, the coil L11, the coil L12, and the coil L13 are Y-connected. More specifically, one end of each of the coil L11, the coil L12, and the coil L13 is connected to a common connection point. The other end of the coil L11 is connected to the terminal A1, the other end of the coil L12 is connected to the terminal A2, and the other end of the coil L13 is connected to the terminal A3.

<Configuration of two-pole yoke magnetizer>
The configuration of the two-pole yoke magnetizer 20 will be described with reference to FIG.
FIG. 5 illustrates the configuration of the two-pole yoke magnetizer 20, FIG. 5 (a) is a perspective view of the two-pole yoke magnetizer 20, and FIG. 5 (b) is the two-pole yoke magnetizer 20. FIG.

  The dipole yoke type magnetizer 20 includes a first magnetizing element 21, a second magnetizing element 22, a base 23 and a dipole yoke 24. The first magnetization element 21 and the second magnetization element 22 are provided at both ends of the base portion 23.

  The bipolar yoke 24 is a yoke formed by laminating silicon steel plates, and has a first magnetic pole 241 and a second magnetic pole 242. An electric wire is wound around the first magnetic pole 241 to constitute a coil L21. The first magnetic element 241 is constituted by the first magnetic pole 241 and the coil L21. An electric wire is wound around the second magnetic pole 242 to constitute a coil L22, and the second magnetic element 242 and the coil L22 constitute the second magnetizing element 22. One end of the coil L21 and the coil L22 is connected to a common connection point. The other end of the coil L21 is connected to the terminal B1, and the other end of the coil L22 is connected to the terminal B2.

<First Example of Magnetizing Device for Inspected Object>
A first embodiment of a magnetizing apparatus for an object to be inspected according to the present invention will be described with reference to FIGS.
FIG. 6 is a configuration diagram illustrating the configuration of the magnetizing apparatus for the device under test according to the first embodiment. FIG. 7 is a connection diagram of the magnetizing apparatus for the device under test according to the first embodiment.

  The magnetizing device for the inspected object of the first embodiment includes a three-pole yoke magnetizer 10 as a “first magnetizer”, a two-pole yoke magnetizer 20 as a “second magnetizer”, and a power supply device 100. It consists of and.

  The three-pole yoke type magnetizer 10 is arranged such that the tips of the first magnetizing element 11, the second magnetizing element 12, and the third magnetizing element 13 face the magnetized region 1 in which the device under test is arranged. More specifically, the three-pole yoke type magnetizer 10 is configured so that the tips of the first magnetization element 11, the second magnetization element 12, and the third magnetization element 13 face the XY plane of the magnetization region 1 (X Arranged so as to face in the axial direction).

  The two-pole yoke type magnetizer 20 is arranged so that the tips of the first magnetizing element 21 and the second magnetizing element 22 face the magnetized region 1 in a direction different from the three-pole yoke type magnetizer 10 by 90 degrees. More specifically, the dipole yoke magnetizer 20 is disposed so that the tips of the first magnetization element 21 and the second magnetization element 22 face the YZ plane of the magnetization region 1.

  The power supply device 100 according to the first embodiment applies a three-phase AC voltage to the three-pole yoke magnetizer 10. More specifically, the power supply device 100 according to the first embodiment connects the R phase of the commercial three-phase AC power source and the terminal A1 of the three-pole yoke magnetizer 10, and the S-phase and the three-pole yoke magnetizer 10. The terminal A2 is connected, and the T phase and the terminal A3 of the three-pole yoke magnetizer 10 are connected. Further, the power supply apparatus 100 according to the first embodiment applies a single-phase AC voltage to the two-pole yoke magnetizer 20. More specifically, the power supply apparatus 100 according to the first embodiment connects the R phase of the commercial three-phase AC power source and the terminal B1 of the two-pole yoke magnetizer 20, and the T-phase and the two-pole yoke magnetizer 20 Connect to terminal B2.

  FIG. 8 schematically shows a Lissajous waveform of a magnetic field generated in the magnetized region 1 in the magnetizing apparatus for an object to be inspected according to the first embodiment. FIG. 8A shows a Lissajous waveform when the three-pole yoke magnetizer 10 is operated alone. FIG. 8B shows the three-pole yoke magnetizer 10 and the two-pole yoke magnetizer 20. It is a Lissajous waveform when operated.

  In the magnetizing apparatus for an object to be inspected in the first embodiment, a three-dimensional probe 51 in which the magnetic flux densities of the X axis, the Y axis, and the Z axis in the magnetization region 1 where the object to be inspected is connected to a teslameter 52 (magnetometer) The Lissajous waveform was observed with an oscilloscope 53 (waveform observation device) that was detected by the (magnetic field detection element) and connected to the teslameter 52. In FIG. 8, the Lissajous waveform in the XY plane is a Lissajous waveform based on the X-axis magnetic flux density and the Y-axis magnetic flux density (first Lissajous waveform). A Lissajous waveform in the YZ plane is a Lissajous waveform based on the Y-axis magnetic flux density and the Z-axis magnetic flux density (second Lissajous waveform). The Lissajous waveform in the Z-X plane is a Lissajous waveform based on the Z-axis magnetic flux density and the X-axis magnetic flux density (third Lissajous waveform).

  First, for comparison with the magnetizing apparatus of the object to be inspected according to the present invention, the Lissajous waveform of the magnetic field when the three-pole yoke type magnetizer 10 was operated alone was observed (FIG. 8A).

  The three-pole yoke-type magnetizer 10 can form a rotating magnetic field in which the strength of the magnetic field is 360 degrees and substantially uniform by applying a three-phase AC voltage. Therefore, in the XY plane, the three-pole yoke magnetizer 10 generates a rotating magnetic field C (FIG. 6) in which the magnetic field strength is approximately 360 degrees and becomes substantially uniform. However, the three-pole yoke magnetizer 10 alone hardly generates a magnetic field of the Z-axis direction component. Therefore, only the magnetic field of the Y-axis direction component is generated on the YZ plane, and only the magnetic field of the X-axis direction component is generated on the ZX plane.

  Next, a Lissajous waveform of the magnetic field was observed in the magnetizing apparatus for the device under test according to the present invention in which the three-pole yoke magnetizer 10 and the two-pole yoke magnetizer 20 were operated (FIG. 8B).

  In the XY plane, the three-pole yoke magnetizer 10 generates a rotating magnetic field C (FIG. 6) having a magnetic field strength of 360 degrees and substantially uniform. Further, the two-pole yoke type magnetizer 20 has a first magnetizing element 21 and a second magnetizing element 22 with the tips of the magnet to be inspected in a direction that is 90 degrees different from the direction in which the three-pole yoke type magnetizer 10 faces the object to be inspected. It is arranged to face each other. Therefore, the YZ plane and the Z− plane are determined by the combined vector of the rotating magnetic field C formed by the three-pole yoke magnetizer 10 in the XY plane and the magnetic field D in the Z-axis direction formed by the two-pole yoke magnetizer 20. A rotating magnetic field is also formed in the X plane. In other words, the magnetizing apparatus for an object to be inspected according to the present invention can form effective rotating magnetic fields on the XY plane, the YZ plane, and the ZX plane, respectively. High magnetic particle flaw detection accuracy can be obtained on the entire plane and the Z-X plane.

  Furthermore, each Lissajous waveform has a more uniform magnetic field strength in the rotating direction of the rotating magnetic field as the aspect ratio value is closer to 1 (for example, the Lissajous waveform is closer to a perfect circle). Therefore, while observing the first to third Lissajous waveforms with the oscilloscope 53, the position or orientation of the three-pole yoke magnetizer 10 or the two-pole yoke magnetizer 20 so that the aspect ratio value of the Lissajous waveform approaches 1 respectively. Can be adjusted. As a result, the magnetizing device of the object to be inspected can be adjusted so that better magnetic particle flaw detection accuracy can be obtained.

  Further, since the three-pole yoke magnetizer 10 and the two-pole yoke magnetizer 20 are both configured using a magnetizing element in which an electric wire is wound around a yoke (yoke), only a conventional air-core exciting coil is used. Thus, a magnetic field having a desired strength can be formed with a much smaller current than that of the magnetized element. Therefore, a commercial three-phase AC power source can be used as it is for the three-pole yoke type magnetizer 10 as in this embodiment.

  Further, since the three-pole yoke magnetizer 10 can form a rotating magnetic field alone, there is a potential between the three-phase AC voltage applied to the three-pole yoke magnetizer 10 and the AC voltage applied to the two-pole yoke magnetizer 20. There is no need to provide a phase difference. Therefore, as the AC voltage applied to the two-pole yoke magnetizer 20, any line voltage of a commercial three-phase AC power source can be used as it is, as in this embodiment. In other words, the magnetizing apparatus for a device to be inspected according to the present invention can use a commercial three-phase AC power source as it is, so that it is not necessary to provide a rectifier or an inverter as in the prior art, and a special power source for obtaining a large current. There is no need to provide a device or the like.

  As described above, according to the present invention, a magnetic particle flaw detector capable of obtaining high magnetic particle flaw detection accuracy in a three-dimensional solid surface of the XY plane, the YZ plane, and the ZX plane is realized at a low cost with a simple configuration. can do.

  In the magnetizing apparatus for the object to be inspected of the first embodiment, the two-pole yoke type magnetizer 20 has the tips of the first magnetizing element 21 and the second magnetizing element 22 and the three-pole yoke type magnetizer 10 serves as the object to be inspected. It arrange | positions so that it may face to-be-inspected object in the direction 90 degree | times different from the direction which faces. Therefore, the magnetic field D (FIG. 6) in the Z-axis direction can be directly formed on the ZX plane or the YZ plane by the two-pole yoke type magnetizer 20. Thereby, a rotating magnetic field (YZ plane and Y-Z plane) by a combined vector of the rotating magnetic field C (FIG. 6) formed by the three-pole yoke magnetizer 10 and the magnetic field D in the Z-axis direction formed by the two-pole yoke magnetizer 20. (Z-X plane rotating magnetic field), the magnetic field strength of the Z-axis direction component can be further increased.

<Second Embodiment of Magnetizing Device for Inspected Object>
A second embodiment of the magnetizing apparatus for an object to be inspected according to the present invention will be described with reference to FIGS.
FIG. 9 is a connection diagram of a magnetizing apparatus for an object to be inspected according to the second embodiment.

In addition to the first embodiment, the magnetizing apparatus for an object to be inspected of the second embodiment includes a rectifier 31, a single-phase inverter circuit 32, and a switching control device 33 as components of the power supply device 100. The rectifier 31 rectifies and smoothes the three-phase AC voltage and outputs a DC voltage. The single phase inverter circuit 32 converts the DC voltage output from the rectifier 31 into a single phase AC voltage. The switching control device 33 performs on / off control of a plurality of switching elements of the single-phase inverter circuit 32 so that a single-phase AC voltage having a predetermined frequency is output from the single-phase inverter circuit 32.
Since the remaining configuration is the same as that of the first embodiment, detailed description thereof is omitted.

  FIG. 10 schematically shows a Lissajous waveform of a magnetic field generated in the magnetization region 1 in the magnetizing apparatus for an object to be inspected according to the second embodiment. FIG. 10A shows a Lissajous waveform when the frequency of the single-phase AC voltage applied to the two-pole yoke magnetizer 20 is 25 Hz, and FIG. 10B shows the application to the two-pole yoke magnetizer 20. It is a Lissajous waveform when the frequency of the single-phase alternating current voltage to be set to 29 Hz.

  Thus, in addition to the first embodiment, a device (rectifier 31, single-phase inverter circuit 32, and switching control device 33) that converts the frequency of the single-phase AC voltage applied to the two-pole yoke magnetizer 20 is further provided. The frequency of the three-phase AC voltage applied to the three-pole yoke magnetizer 10 is preferably different from the frequency of the single-phase AC voltage applied to the two-pole yoke magnetizer 20. This is because a phase shift corresponding to the frequency ratio between the three-phase AC voltage applied to the first magnetizer and the AC voltage applied to the second magnetizer occurs.

  For example, the frequency of the single-phase AC voltage applied to the two-pole yoke magnetizer 20 is set to 25 Hz with respect to the frequency of the three-phase AC voltage applied to the three-pole yoke magnetizer 10 of 50 Hz. In other words, the relationship is set such that the frequency of the three-phase AC voltage applied to the three-pole yoke magnetizer 10 and the frequency of the single-phase AC voltage applied to the two-pole yoke magnetizer 20 are multiplied (FIG. 10A). . Further, for example, the frequency of the single-phase AC voltage applied to the two-pole yoke magnetizer 20 is set to 29 Hz with respect to the frequency of 50 Hz of the three-phase AC voltage applied to the three-pole yoke magnetizer 10. That is, the relationship is set such that the frequency of the three-phase AC voltage applied to the three-pole yoke magnetizer 10 and the frequency of the single-phase AC voltage applied to the two-pole yoke magnetizer 20 are not multiplied (FIG. 10B). ).

  The frequency of the three-phase AC voltage applied to the three-pole yoke magnetizer 10 and the frequency of the single-phase AC voltage applied to the two-pole yoke magnetizer 20 are made different from each other, so that the three-pole yoke magnetizer 10 is applied. There is a phase shift between the three-phase AC voltage and the single-phase AC voltage applied to the two-pole yoke magnetizer 20 according to the frequency ratio between the two. As a result, as shown in FIG. 10, a rotating magnetic field (YZ plane and Z) by a combined vector of the rotating magnetic field C formed by the three-pole yoke magnetizer 10 and the magnetic field D formed by the two-pole yoke magnetizer 20 is used. −X plane rotating magnetic field), the magnetic field strength of the Z-axis direction component can be increased.

  In particular, it is more effective if the frequency of the three-phase AC voltage applied to the three-pole yoke magnetizer 10 and the frequency of the single-phase AC voltage applied to the two-pole yoke magnetizer 20 are set to be non-multiplied. preferable. This is because an irregular phase shift occurs between the three-phase AC voltage applied to the first magnetizer and the AC voltage applied to the second magnetizer. The frequency of the single-phase AC voltage applied to the two-pole yoke magnetizer 20 is such that the lower the frequency, the easier the magnetic force penetrates to the deep part of the object to be inspected.

  Further, while observing the first to third Lissajous waveforms with the oscilloscope 53, the position or orientation of the three-pole yoke magnetizer 10 or the two-pole yoke magnetizer 20 so that the aspect ratio value of the Lissajous waveform approaches 1 respectively. The frequency of the alternating voltage applied to the two-pole yoke magnetizer 20 is adjusted. Thereby, better magnetic particle flaw detection accuracy can be obtained.

<Third Example of Magnetizing Device for Inspected Object>
A third embodiment of the magnetizing apparatus for an object to be inspected according to the present invention will be described with reference to FIGS.
FIG. 11 is a configuration diagram illustrating the configuration of a magnetizing apparatus for an object to be inspected according to the third embodiment. FIG. 12 is a connection diagram of a magnetizing apparatus for an object to be inspected according to the third embodiment.

  The magnetizing device for the inspected object of the third embodiment includes two three-pole yoke magnetizers 10a and 10b as “first magnetizer” and “second magnetizer”, and a power supply device 100. .

The three-pole yoke type magnetizer 10a as the “first magnetizer” is such that the tips of the first magnetizing element 11, the second magnetizing element 12, and the third magnetizing element 13 face the XY plane of the magnetized region 1. Is arranged. On the other hand, the three-pole yoke magnetizer 10b as the “second magnetizer” is magnetized at the tips of the first magnetizing element 11, the second magnetizing element 12 and the third magnetizing element 13, and the three-pole yoke magnetizer 10a. They are arranged so as to face the XY plane of the magnetization region 1 from the direction facing the direction facing the region 1.
The three-pole yoke magnetizers 10a and 10b have the same configuration as the three-pole yoke magnetizer 10 illustrated and described with reference to FIGS.

  The power supply apparatus 100 according to the third embodiment applies a three-phase AC voltage to the three-pole yoke magnetizer 10a. More specifically, the power supply device 100 of the third embodiment connects the R phase of the commercial three-phase AC power source and the terminal A1 of the three-pole yoke magnetizer 10a, and the S-phase and the three-pole yoke magnetizer 10a. The terminal A2 is connected, and the T phase and the terminal A3 of the three-pole yoke magnetizer 10a are connected. Further, the power supply apparatus 100 of the third embodiment applies a single-phase AC voltage to the three-pole yoke magnetizer 10b. More specifically, the power supply device 100 of the third embodiment connects the R phase of the commercial three-phase AC power source and the terminal A1 of the three-pole yoke magnetizer 10b, and the T-phase and the three-pole yoke magnetizer 10b. Connect to terminal A3.

  In the XY plane, a rotating magnetic field C having a magnetic field strength of 360 degrees and substantially uniform is generated by the three-pole yoke magnetizer 10a. A magnetic field E is generated by the three-pole yoke magnetizer 10b on the opposite XY plane across the magnetized region 1. Therefore, a magnetic field D in the Z-axis direction is formed by a combined vector of the rotating magnetic field C formed by the three-pole yoke type magnetizer 10a and the magnetic field E formed by the three-pole yoke type magnetizer 10b. A rotating magnetic field is also formed in the ZX plane. Further, the combined vector of the rotating magnetic field C formed by the three-pole yoke magnetizer 10a and the magnetic field E formed by the three-pole yoke magnetizer 10b has more components in the opposing direction (Z-axis direction component). Thereby, the magnetic field strength of the Z-axis direction component can be effectively increased in the rotating magnetic field (rotating magnetic field in the YZ plane and ZX plane) by the combined vector.

<Fourth Example of Magnetizing Device for Inspected Object>
A fourth embodiment of the magnetizing apparatus for an object to be inspected according to the present invention will be described with reference to FIG.
FIG. 13 is a connection diagram of a magnetizing apparatus for an object to be inspected according to the fourth embodiment.

In addition to the third embodiment, the magnetizing device for a device to be inspected of the fourth embodiment includes a rectifier 31, a single-phase inverter circuit 32, and a switching control device 33 as components of the power supply device 100.
Since the remaining configuration is the same as that of the third embodiment, detailed description thereof is omitted. Further, the configurations of the rectifier 31, the single-phase inverter circuit 32, and the switching control device 33 are the same as those in the second embodiment, and thus detailed description thereof is omitted.

  Thus, in addition to the third embodiment, a device for converting the frequency of the single-phase AC voltage applied to the three-pole yoke magnetizer 10b (rectifier 31, single-phase inverter circuit 32, and switching control device 33) is further provided. It is preferable that the frequency of the three-phase AC voltage applied to the three-pole yoke magnetizer 10a is different from the frequency of the single-phase AC voltage applied to the three-pole yoke magnetizer 10b.

  The frequency of the three-phase AC voltage applied to the three-pole yoke magnetizer 10a is made different from the frequency of the single-phase AC voltage applied to the three-pole yoke magnetizer 10b, so that the three-pole yoke magnetizer 10a is applied. There is a phase shift between the three-phase AC voltage and the single-phase AC voltage applied to the three-pole yoke magnetizer 10b according to the frequency ratio between the two. Thereby, in a rotating magnetic field (rotating magnetic field of YZ plane and ZX plane) by a combined vector of the rotating magnetic field C formed by the three-pole yoke magnetizer 10a and the magnetic field E formed by the three-pole yoke magnetizer 10b. The magnetic field strength of the Z-axis direction component can be increased. In particular, it is more effective if the relationship is set such that the frequency of the three-phase AC voltage applied to the three-pole yoke magnetizer 10a and the frequency of the single-phase AC voltage applied to the three-pole yoke magnetizer 10b are not multiplied. preferable.

<Fifth Example of Magnetizing Device for Inspected Object>
A fifth embodiment of the magnetizing apparatus for an object to be inspected according to the present invention will be described with reference to FIGS.
FIG. 14 is a configuration diagram illustrating the configuration of a magnetizing apparatus for an object to be inspected according to the fifth embodiment. FIG. 15 is a connection diagram of a magnetizing apparatus for an object to be inspected according to the fifth embodiment.

  The magnetizing apparatus for an object to be inspected of the fifth embodiment has the same configuration as that of the third embodiment except that a three-phase AC voltage is applied to a three-pole yoke magnetizer 10b as a “second magnetizer”. More specifically, the power supply device 100 of the fifth embodiment connects the R phase of the commercial three-phase AC power source and the terminal A1 of the three-pole yoke magnetizer 10b, and the S-phase and the three-pole yoke magnetizer 10b. The terminal A2 is connected, and the T phase and the terminal A3 of the three-pole yoke magnetizer 10b are connected.

  In the magnetizing apparatus for an object to be inspected having such a configuration, a rotating magnetic field C1 is formed on an XY plane by a three-pole yoke magnetizer 10a as a “first magnetizer”. Furthermore, a rotating magnetic field C2 is formed on the XY plane on the opposite side across the magnetization region 1 by a three-pole yoke magnetizer 10b as a “second magnetizer”. Therefore, a magnetic field D in the Z-axis direction is formed by a combined vector of the rotating magnetic field C1 formed by the three-pole yoke type magnetizer 10a and the rotating magnetic field C2 formed by the three-pole yoke type magnetizer 10b, and thereby the YZ plane. A rotating magnetic field is also formed in the ZX plane. Further, the combined vector of the rotating magnetic field C1 formed by the three-pole yoke magnetizer 10a and the rotating magnetic field C2 formed by the three-pole yoke magnetizer 10b has a larger magnetic field of the component in the opposite direction (Z-axis direction component). . Thereby, the magnetic field strength of the Z-axis direction component can be effectively increased in the rotating magnetic field (rotating magnetic field in the YZ plane and ZX plane) by the combined vector.

<Sixth Example of Magnetizing Device for Inspected Object>
A sixth embodiment of the magnetizing apparatus for an object to be inspected according to the present invention will be described with reference to FIG.
FIG. 16 is a connection diagram of a magnetizing apparatus for an object to be inspected according to the sixth embodiment.

  In addition to the fifth embodiment, the magnetizing apparatus for a device to be inspected of the sixth embodiment includes a rectifier 31, a three-phase inverter circuit 34, and a switching control device 35 as components of the power supply device 100. The rectifier 31 rectifies and smoothes the three-phase AC voltage and outputs a DC voltage. The three-phase inverter circuit 34 converts the DC voltage output from the rectifier 31 into a three-phase AC voltage. The switching control device 35 performs on / off control of a plurality of switching elements of the three-phase inverter circuit 34 so that a three-phase AC voltage having a predetermined frequency is output from the three-phase inverter circuit 34.

  Since the remaining configuration is the same as that of the sixth embodiment, detailed description thereof is omitted.

  Thus, in addition to the fifth embodiment, a device (rectifier 31, three-phase inverter circuit 34 and switching control device 35) for converting the frequency of the three-phase AC voltage applied to the three-pole yoke magnetizer 10b is further provided. The frequency of the three-phase AC voltage applied to the three-pole yoke magnetizer 10a as the “first magnetizer” and the frequency of the three-phase AC voltage applied to the three-pole yoke magnetizer 10b as the “second magnetizer” Are preferably different.

  The frequency of the three-phase AC voltage applied to the three-pole yoke magnetizer 10a is made different from the frequency of the three-phase AC voltage applied to the three-pole yoke magnetizer 10b, thereby applying the three-pole yoke magnetizer 10a. There is a phase shift between the three-phase AC voltage and the three-phase AC voltage applied to the three-pole yoke magnetizer 10b in accordance with the frequency ratio between them. As a result, a rotating magnetic field (rotating magnetic fields in the YZ plane and the ZX plane) by a combined vector of the rotating magnetic field C1 formed by the three-pole yoke magnetizer 10a and the rotating magnetic field C2 formed by the three-pole yoke magnetizer 10b. ), The magnetic field strength of the Z-axis direction component can be increased. In particular, if the relationship between the frequency of the three-phase AC voltage applied to the three-pole yoke magnetizer 10a and the frequency of the three-phase AC voltage applied to the three-pole yoke magnetizer 10b is set to be non-multiplied, the first magnetizer Since an irregular phase shift occurs between the three-phase AC voltage applied to and the AC voltage applied to the second magnetizer, it is more effective and preferable.

<Seventh Embodiment of Magnetizing Device for Inspected Object>
A seventh embodiment of the magnetizing apparatus for an object to be inspected according to the present invention will be described with reference to FIG.
FIG. 17 illustrates a three-pole yoke type magnetizer 10a and a three-pole yoke type magnetizer 10b in the magnetizing apparatus for an object to be inspected in the seventh embodiment, and FIG. 17 (a) shows a three-pole yoke type magnetizer. FIG. 17B is a front view of the three-pole yoke magnetizer 10b.

  The magnetizing apparatus for an object to be inspected according to the seventh embodiment has a relative position between a three-pole yoke magnetizer 10a as a “first magnetizer” and a three-pole yoke magnetizer 10b as a “second magnetizer”. The configuration is the same as that of the fifth or sixth embodiment except that the relationship is different. More specifically, the three-pole yoke magnetizer 10a and the three-pole yoke magnetizer 10b have three magnetizing elements (first magnetizing element 11, second magnetizing element 12, and third magnetizing element 13) having X−. They are arranged so as to face each other with a phase difference by an angle F in the rotational direction along the Y plane.

  With such an arrangement, a phase shift occurs between the rotating magnetic field C1 formed by the three-pole yoke magnetizer 10a and the rotating magnetic field C2 formed by the three-pole yoke magnetizer 10b. As a result, a rotating magnetic field (rotating magnetic fields in the YZ plane and the ZX plane) by a combined vector of the rotating magnetic field C1 formed by the three-pole yoke magnetizer 10a and the rotating magnetic field C2 formed by the three-pole yoke magnetizer 10b. ), The magnetic field strength of the Z-axis direction component can be further increased.

<Eighth Example of Magnetizing Device for Inspected Object>
An eighth embodiment of the magnetizing apparatus for an object to be inspected according to the present invention will be described with reference to FIG.
FIG. 18 is a configuration diagram illustrating the configuration of the magnetizing device for an inspected object according to the eighth embodiment.

  The magnetizing apparatus for an object to be inspected of the eighth embodiment has a relative position between a three-pole yoke magnetizer 10a as a “first magnetizer” and a three-pole yoke magnetizer 10b as a “second magnetizer”. The configuration is the same as that of the third to sixth embodiments except that the relationship is different. More specifically, the three-pole yoke magnetizer 10a and the three-pole yoke magnetizer 10b are arranged with an opposing angle G. This opposing angle G is set to an angle of 20 to 35 degrees in particular in order to bring the rotating magnetic fields of the YZ plane and the ZX plane close to a rotating magnetic field with a magnetic field strength of 360 degrees and almost uniform. Is preferred.

  With such an arrangement, between the rotating magnetic field C (or rotating magnetic field C1) formed by the three-pole yoke magnetizer 10a and the magnetic field E (or rotating magnetic field C2) formed by the three-pole yoke magnetizer 10b. The magnetic field distribution is biased. Thus, in a rotating magnetic field (rotating magnetic field in the YZ plane and the ZX plane) by a combined vector of the magnetic field formed by the three-pole yoke magnetizer 10a and the magnetic field formed by the three-pole yoke magnetizer 10b, Z The magnetic field strength of the axial component can be further increased.

<Ninth Embodiment of Magnetizing Device for Inspected Object>
A ninth embodiment of the magnetizing apparatus for an object to be inspected according to the present invention will be described with reference to FIG.
FIG. 19 is a configuration diagram illustrating the configuration of a magnetizing apparatus for an object to be inspected according to the ninth embodiment.

  The magnetizing apparatus for the inspected object of the ninth embodiment has a relative position between the three-pole yoke magnetizer 10a as the “first magnetizer” and the three-pole yoke magnetizer 10b as the “second magnetizer”. The configuration is the same as that of the third to sixth embodiments except that the relationship is different. More specifically, the three-pole yoke magnetizer 10a and the three-pole yoke magnetizer 10b are the magnetic field centers of the three-pole yoke magnetizer 10a (the first magnetizing element 11, the second magnetizing element 12, and the third magnetizing magnet). The center of the element 13) and the magnetic field center of the three-pole yoke magnetizer 10 b are arranged so as to be shifted by a distance H in a direction (direction along the XY plane) intersecting the facing direction (Z-axis direction).

  With such an arrangement, between the rotating magnetic field C (or rotating magnetic field C1) formed by the three-pole yoke magnetizer 10a and the magnetic field E (or rotating magnetic field C2) formed by the three-pole yoke magnetizer 10b. A gradient occurs in the magnetic field distribution. Thus, in a rotating magnetic field (rotating magnetic field in the YZ plane and the ZX plane) by a combined vector of the magnetic field formed by the three-pole yoke magnetizer 10a and the magnetic field formed by the three-pole yoke magnetizer 10b, Z The magnetic field strength of the axial component can be further increased.

<Other embodiments and modifications>
The present invention is not particularly limited to the embodiments described above, and it goes without saying that various modifications are possible within the scope of the invention described in the claims.

DESCRIPTION OF SYMBOLS 1 Magnetization area 10, 10a, 10b Three pole yoke type magnetizer, 20 Two pole yoke type magnetizer,
31 Rectifier, 32 Single-phase inverter circuit, 34 Three-phase inverter circuit,
33, 35 Switching control device, 51 Three-dimensional probe, 52 Teslameter,
53 Oscilloscope, 100 power supply

Claims (1)

A first magnetizer in which three magnetizing elements each having a wire wound around a yoke are arranged with a phase difference of 120 degrees from each other, and the wires of the three magnetizing elements are Δ-connected or Y-connected; A second magnetizer that faces the object to be inspected in a direction different from that of the first magnetizer, a three-phase AC voltage is applied to the first magnetizer, and an AC voltage is applied to the first magnetizer. A method of adjusting a magnetizing device of an object to be inspected, comprising: a power supply device applied to two magnetizers;
Detect the magnetic field strength of the X-axis, Y-axis, and Z-axis in the area where the object to be inspected is installed with a magnetic field detector connected to the magnetometer ,
First Lissajous waveform based on X-axis magnetic field strength and Y-axis magnetic field strength, second Lissajous waveform based on Y-axis magnetic field strength and Z-axis magnetic field strength, Z-axis magnetic field strength and X-axis magnetic field any one or two or more third Lissajous waveform by the strength of the magnetic field observed by the waveform observer connected to the magnetic measuring device,
The position or orientation of the first magnetizer or the second magnetizer, the three-phase AC voltage applied to the first magnetizer, and the first so that the value of the aspect ratio of the Lissajous waveform being observed approaches 1. A method for adjusting a magnetizing apparatus for an object to be inspected, characterized in that a frequency ratio with an alternating voltage applied to a two magnetizer is adjusted.

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