JP2010117340A - Magnetizer and magnetic particle testing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To detect decline of a magnetomotive force of a magnetizer by a simple constitution, and to improve reliability and workability of measurement. <P>SOLUTION: The magnetizer 1 and a magnetic particle testing device 20 include: an excitation coil 4 wound around a magnetic core 2 positioned close to an inspection object 10, for generating a magnetic path in the magnetic core 2; a first winding coil 6 wound around the magnetic core 2; and a first light emitting part 12 connected to the first winding coil 6, for emitting a visible ray when the magnetomotive force of the excitation coil 4 is stronger than a prescribed value. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a magnetizer (hand magna) and a magnetic particle flaw detection device used when magnetic particle flaw detection is performed on a defect of an inspection object such as a steel material or a steel part.

  In a wide range of technical fields such as shipbuilding, aviation, railways, and nuclear power, the magnetic particle testing method is used as a nondestructive inspection method for inspecting inspected objects such as steel materials and steel parts. The magnetic particle testing method is to magnetize the object to be inspected, spray the magnetic powder liquid onto the area where the leakage magnetic flux of the defect occurs, and observe the magnetic powder pattern by irradiating with ultraviolet rays. It has characteristics.

Recently, a portable battery-operated AC interpole magnetic particle flaw detector has been developed. The AC interpole type magnetic particle flaw detector does not require wiring of a power cable, so that the operator can perform a magnetic particle flaw detection test in a short time with little effort without being restricted by a place.
Patent Document 1 discloses an example of an AC interpole type magnetic particle flaw detector.

  FIG. 8 is a diagram showing a configuration of a conventional magnetic particle flaw detector 40. The magnetic particle flaw detector 40 includes a battery power source 42, an inverter circuit 44 connected to the battery power source 42, and a magnetizer 46 that is connected to the inverter circuit 44 and detects a defect of the inspection object 50. Further, the magnetic particle flaw detector 40 includes a power supply voltage detection circuit 48 that detects a decrease in the voltage of the battery power supply 42 and notifies the battery replacement time.

FIG. 9 shows an example of the power supply voltage detection circuit 48 provided in the magnetic particle flaw detector 40.
The power supply voltage detection circuit 48 includes a comparator, a logic circuit, an alarm circuit, a light emitting diode circuit, and the like. A conventional magnetic particle flaw detector includes an ultraviolet light emitting diode (LED) that irradiates magnetic powder with ultraviolet light, and a dedicated power source (not shown) for causing the ultraviolet light emitting diode to emit light.

JP 2007-33043 A

In general, the magnetic particle flaw detector 40 does not include means for detecting a decrease in magnetomotive force due to a decrease in the voltage of the battery power source 42. For this reason, the magnetic particle flaw detection test may be performed in a state where the magnetomotive force of the magnetizer 46 is lowered, and the measurement accuracy and measurement reliability may be lowered.
In some cases, the magnetizer 46 is provided with a dedicated external circuit for measuring the magnetomotive force. However, if a dedicated external circuit is provided in the magnetizer 46, the magnetic particle flaw detector 40 becomes complicated and large.

  An object of the present invention is to provide a magnetizer and a magnetic particle flaw detector capable of detecting a decrease in magnetomotive force with a simple configuration and improving measurement reliability and workability.

  In order to achieve the above object, a magnetizer according to the present invention is wound around a magnetic core close to an object to be inspected, an excitation coil for generating a magnetic path in the magnetic core, and a first coil wound around the magnetic core. 1 winding coil, and a first light emitting unit that is connected to the first winding coil and emits visible light when the magnetomotive force of the exciting coil is equal to or greater than a predetermined value.

  The magnetic particle flaw detector according to the present invention includes an inverter circuit that converts DC power supplied from a power source into AC power, and is wound around a magnetic core that is connected to the inverter circuit and is close to an object to be inspected. An excitation coil that generates a magnetic path, a first winding coil wound around a magnetic core, and a first winding coil connected to the first winding coil, and the magnetomotive force of the excitation coil is a predetermined value or more, A first light emitting unit that emits visible light.

  According to the present invention, by connecting the first light-emitting unit that emits visible light to the first winding coil, it is possible to reliably detect the battery replacement time with a simple configuration, It has the effect of improving measurement reliability and workability.

It is an appearance perspective view showing an example of composition of a magnetizer concerning a 1st embodiment of the present invention. It is a block diagram which shows the example of an internal structure of the magnetic particle testing apparatus which concerns on the 1st Embodiment of this invention. It is explanatory drawing which shows the usage example in case an operator carries the magnetic particle testing apparatus which concerns on the 1st Embodiment of this invention. It is a figure which shows the example of the 4 pole alternating current pole magnetizer which concerns on the 1st Embodiment of this invention. It is a figure which shows the example of the 4 pole alternating current pole magnetizer which concerns on the 1st Embodiment of this invention. It is an external appearance perspective view which shows the structural example of the magnetic particle testing apparatus which concerns on the 2nd Embodiment of this invention. It is a block diagram which shows the example of an internal structure of the magnetic particle testing apparatus which concerns on the 2nd Embodiment of this invention. It is a figure which shows the structural example of the conventional magnetic particle flaw detector. It is a figure which shows an example of the power supply voltage detection circuit with which the conventional magnetic particle testing apparatus is provided.

  A first embodiment of the present invention will be described with reference to FIGS. In addition, the same referential mark is attached | subjected to the same component and description is abbreviate | omitted.

FIG. 1 is a diagram illustrating an example of a magnetizer 1 according to the first embodiment of the present invention.
The magnetizer 1 is wound around a U-shaped magnetic core 2 close to the object to be inspected 10, an excitation coil 4 that generates a magnetic path in the magnetic core 2, and a first wound around the magnetic core 2. A winding coil 6 and a first light emitting unit 12 that emits visible light when the magnetomotive force of the exciting coil 4 is greater than or equal to a predetermined value are connected to the first winding coil 6. In addition, the magnetizer 1 includes a second winding coil 8 that is wound around the magnetic core 2.

The 1st light emission part 12 displays to a worker whether a magnetomotive force (power supply voltage) is more than predetermined value by light-emitting visible light. A second light emitting unit 16 that emits ultraviolet rays is connected to the second winding coil 8.
In this example, a visible light emitting diode is used as the first light emitting unit 12, and an ultraviolet light emitting light emitting diode is used as the second light emitting unit 16.

  The magnetic core 2 forms a magnetic loop between the magnetic core 2 and the inspection object 10 by bringing the base portion close to or in contact with the inspection object 10. The magnetic core 2 is formed with a size and weight that can be carried by an operator. The magnetic core 2 may be constituted by a cut core formed of a 3% silicon steel plate. The operator can detect the defect of the inspection object 10 by immersing the surface of the defect portion of the inspection object 10 with the magnetic powder liquid.

  FIG. 2 is a block diagram illustrating an internal configuration example of the magnetic particle flaw detector 20 including the magnetizer 1.

  The magnetic particle flaw detector 20 includes a battery power source 22, an inverter circuit 24 connected to the battery power source 22, and a magnetizer 1 connected to the inverter circuit 24 and detecting a defect of the inspection object 10.

  The DC power of the battery power source 22 is converted into AC power by an inverter circuit, and the current frequency and current magnitude are controlled. Since the frequency and magnitude of the current can be made variable, both the magnetization and demagnetization of the inspection object 10 can be performed by the magnetizer 1 and the magnetic particle flaw detector 20 using the magnetizer 1.

  Lead-acid batteries have the disadvantages of being unsuitable for environmental impacts and repeated charge / discharge. For this reason, for example, a nickel metal hydride battery is used as the battery power source 22. For example, as the battery power source 22, a 24 V nickel-metal hydride battery is boosted and the inverter circuit 24 is driven at 64 V, and an AC magnetizing current of 10 to 50 Hz is supplied to the exciting coil 4. As a result, a magnetic path is generated in the magnetic core 2, and the object to be inspected 10 adjacent to both ends of the magnetic core 2 is magnetized.

  Since the magnetic particle flaw detector 20 uses an alternating current having a frequency lower than the commercial frequency, the impedance can be kept low, and a magnetic particle flaw inspection can be performed at a low voltage. In addition, since an alternating current having a frequency lower than the commercial frequency is used, the voltage waveform is not a complete sine wave but a voltage waveform including a harmonic component.

  Here, the number of windings of the first winding coil 6 is determined according to the following conditions. In this example, when the magnetomotive force of the magnetic core 2 is greater than or equal to a predetermined value required for magnetic particle inspection, the first light emitting unit 12 is turned on.

  For example, the number of turns for turning on the first light emitting unit 12 is dΦ / dt × N = 1.5 (Wb / m 2) × 0.02 × 0.02 / 0.008 × N = 1V Therefore, it is required that N = 13 turns.

  On the other hand, the operator can inspect the defect of the inspection object 10 by irradiating the magnetic powder blown to the defect part of the inspection object 10 with the ultraviolet light emitted from the second light emitting unit 16. The 2nd light emission part 16 is accommodated in the storage container not shown.

  For example, the number of turns for turning on the second light emitting unit 16 is dΦ / dt × N = 1.5 (Wb / m 2) × 0.02 × 0.02 / 0.008 × N = 5V. From this, N = 67 turns. By setting the number of turns of the second winding coil 8 to, for example, about N = 100 turns, the second light emitting unit 16 can receive power from the magnetizer 1.

  The magnetic core 2 is composed of a cut core formed of a 3% silicon steel plate. The magnetic core 2 formed of 3% silicon steel sheet can increase the magnetic permeability compared to the magnetic core formed by laminating silicon steel sheets, and reduce the excitation current for a certain voltage. Can do.

  Thereby, the cross-sectional area of the magnetic core 2 and the winding diameter of the exciting coil 4 can be reduced, and the magnetizer 1 and the magnetic particle flaw detector 20 can be reduced in size and weight. In addition, when the battery power source 22 is used, since the time that can be used by one charge becomes long, the operator can expand the inspection range.

  FIG. 3 shows an example of use when the operator carries the magnetic particle flaw detectors 20 and 20 ′.

FIG. 3A shows a usage example of the magnetic particle flaw detector 20 connected to the battery power source 22.
The worker wears the battery power source 22 and the inverter circuit 24 stored in the storage container 25 using the belt strap 27 or the shoulder strap 28. Then, the worker carries the magnetizer 1 connected to the battery power source 22 and the inverter circuit 24 via the connection cable 26.

  In the magnetic particle flaw detector 20, since a power cable connected to a commercial AC power supply is not required, workability is greatly improved in operations such as gas tanks and ship bottoms. Further, since the magnetic particle flaw detector 20 can be attached by the belt strap 27 or the shoulder strap 28, the workability and safety when the worker moves up and down the ladder or works in a high place or a narrow place are improved. It can be greatly improved.

FIG. 3B shows a usage example of the magnetic particle flaw detector 20 ′ that takes in electric power from a commercial power source.
The magnetic particle flaw detector 20 ′ is different from the magnetic particle flaw detector 20 in that it includes a power plug 29 that supplies AC power from a commercial power source instead of the battery power source 22.
If the magnetic particle flaw detector 20 'is configured in this way, the magnetic particle flaw detector 20' can be reduced in weight by the amount of the battery power source 22.

4A to 4E, FIG. 5A, and FIG. 5B show an example in which two electromagnets of a two-pole AC interpole magnetizer are combined to form a four-pole AC interpole magnetizer.
4A to 4E, 5A, and 5B show examples of the arrangement relationship of the magnetizer 1, the magnetic core 2, and the exciting coil 4, respectively. That is, as a form of combining magnets, for example, the X type shown in FIG. 4A, the H type shown in FIG. 4B, the HL type shown in FIG. 4C, the D type shown in FIG. 4D, the C type shown in FIG. Alternatively, the R type shown in FIGS. 5A and 5B is used.

  Such a 4-pole AC interpole magnetizer is configured such that adjacent magnetic poles are different. In order to generate a rotating magnetic field, a phase difference of 60 to 120 degrees is generated between two sets of magnetizing currents. This rotating magnetic field makes it possible to perform a magnetic particle flaw detection on the inspection object 10 regardless of the installation direction of the magnetizer 1.

  According to the magnetizer 1 and the magnetic particle flaw detector 20 according to the first embodiment described above, a decrease in magnetomotive force is displayed by connecting the first light emitting unit 12 to the first winding coil 6. Therefore, it is possible to detect a decrease in magnetomotive force of the magnetic core 2 without separately providing a dedicated circuit. Thereby, the operator who uses the magnetizer 1 or the magnetic particle flaw detector 20 can know when to replace the battery power source 22. Further, the magnetic particle flaw detector 20 can be reduced in size and price as compared with a magnetic particle flaw detector provided with a dedicated circuit for displaying a magnetomotive force decrease.

  In addition, since the second light emitting unit 16 is mounted on the magnetic core 2, it is not necessary to work with the second light emitting unit 16 in hand, thereby improving the workability of the operator. In addition, the magnetizer 1 and the second light emitting unit 16 can be operated while carrying the battery power source 22. This eliminates the need for an AC power cable for connection to a commercial AC power supply, thereby improving workability.

  In addition, the electric power necessary for the second light emitting unit 16 is supplied from the battery power source 22 via the second winding coil 8 and the excitation coil 4. This eliminates the need for a separate power source for causing the second light emitting unit 16 to emit light, and has the effect of reducing the weight of the magnetizer 1 and the magnetic particle flaw detector 20.

  Next, a magnetizer 30 and a magnetic particle flaw detector 36 according to a second embodiment of the present invention will be described. In the following description, parts corresponding to those in FIGS. 1 and 2 already described in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

FIG. 6 is an external perspective view showing an external configuration example of the magnetizer 30.
The magnetizer 30 includes a storage member 31 attached to one end of the magnetic core 2, an excitation coil 4 stored in the storage member 31, a second winding coil 8, and a rectifier 32. The storage member 31 can be removed from the magnetic core 2 as appropriate, and is configured to be easily maintained by an operator. The rectifier 32 incorporates an electronic component such as a capacitor and is connected to the second light emitting unit 16. For this reason, the second light emitting unit 16 is supplied with the DC power obtained by converting the AC power by the rectifier 32.

  The storage member 31 includes a support portion 33 for arbitrarily changing the irradiation direction of the second light emitting portion 16. Since the rotating shaft of the second light emitting unit 16 is supported by the support unit 33, it is possible to irradiate ultraviolet rays to any place of the inspection object 10.

  Further, a switch 34 is mounted on the lower surface of the magnetic core 2 to switch on / off when the operator magnetizes the object 10 to be inspected. A claw portion 35 is attached. The claw portion 35 can be attached to and detached from the magnetic core 2 and can be bent at an arbitrary angle according to the shape of the inspection object 10 so that the inspection object 10 can be surely magnetized.

  In this example, the excitation coil 4 is arranged in the lower layer of the storage member 31 and the second winding coil 8 is arranged in the upper layer. Since the second winding coil 8 is wound on the insulating coating exciting coil 4, the exciting coil 4 and the second winding coil 8 are not short-circuited. In addition, the first winding coil 6 and the first light emitting unit 12 are embedded in the magnetic core 2 and are not shown in FIG. It can be confirmed whether the light emitting unit 12 is turned on or off.

FIG. 7 is a block diagram showing an example of the internal configuration of the magnetic particle inspection device 36.
The magnetic particle inspection device 36 includes a magnetizer 30 and the basic configuration is the same as that of the magnetic particle inspection device 20 described above.

  According to the magnetizer 30 and the magnetic particle flaw detector 36 according to the second embodiment described above, the rectifier 32 is provided between the second winding coil 8 and the second light emitting unit 16. Thereby, the 2nd light emission part 16 can irradiate the test | inspection site | part of the to-be-inspected object 10 with an ultraviolet-ray, maintaining predetermined light intensity. For this reason, there is an effect that the light intensity of ultraviolet rays is stabilized and the accuracy of inspection can be increased.

  DESCRIPTION OF SYMBOLS 1 ... Magnetizer, 2 ... Magnetic core, 4 ... Excitation coil, 6 ... 1st winding coil, 8 ... 2nd winding coil, 10 ... Test object, 12 ... 1st light emission part, 16 ... 1st 2 light emitting units, 20 ... magnetic particle flaw detector, 20 '... magnetic particle flaw detector, 22 ... battery power supply, 24 ... inverter circuit, 25 ... storage container, 26 ... connection cable, 27 ... belt strap, 28 ... shoulder strap, 29 ... Power plug, 30 ... Magnetizer, 31 ... Storage member, 32 ... Rectifier, 33 ... Supporting part, 34 ... Switch, 35 ... Claw part, 36 ... Magnetic particle flaw detector

Claims (6)

An exciting coil that is wound around a magnetic core close to the object to be inspected and generates a magnetic path in the magnetic core;
A first winding coil wound around the magnetic core;
A first light emitting unit that is connected to the first winding coil and emits visible light when the magnetomotive force of the exciting coil is equal to or greater than a predetermined value. A second winding coil wound around the magnetic core;
The magnetizer according to claim 1, further comprising: a second light emitting unit that is connected to the second coil and emits ultraviolet light. 3. The magnetizer according to claim 2, further comprising a rectifier that converts AC power supplied to the second light emitting unit into DC power between the second winding coil and the second light emitting unit. The magnetizer according to any one of claims 1 to 3, wherein the magnetic core is constituted by a cut core. The magnetizer according to any one of claims 1 to 4, wherein a rotating magnetic field is formed by the magnetic core and the exciting coil. An inverter circuit for converting DC power supplied from a power source into AC power;
An excitation coil connected to the inverter circuit, wound around a magnetic core close to the object to be inspected, and generating a magnetic path in the magnetic core;
A first winding coil wound around the magnetic core;
A magnetic particle flaw detector comprising: a first light-emitting unit that is connected to the first winding coil and emits visible light when the magnetomotive force of the excitation coil is equal to or greater than a predetermined value.

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