JP2019203782A - Magnetic substance inspection apparatus - Google Patents

Abstract

To provide a magnetic substance inspection apparatus capable of also detecting abnormality other than disconnection in addition to abnormality of the disconnection of a magnetic substance inspection apparatus.SOLUTION: A magnetic substance inspection apparatus 100 comprises: a differential coil 10 detecting variations of a magnetic field of a wire rope W and transmitting a detection signal; an excitation coil 13 for exciting a magnetization state of the wire rope W; an abnormality determination coil 14 varying a magnetic field applied to the differential coil 10; and a control unit 21 that determines presence/absence of abnormality of the magnetic substance inspection apparatus 100 based on a variation of the magnetic field, applied to the differential coil 10 by the abnormality determination coil 14, and a detection signal.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a magnetic substance inspection apparatus, and more particularly to a magnetic substance inspection apparatus including a coil.

  Conventionally, an apparatus provided with a coil is known (for example, refer to patent documents 1).

  In Patent Document 1, a differential transformer that includes a coil and outputs a differential signal, a transmitter that applies an excitation voltage to the primary side of the differential transformer, and a differential signal of the differential transformer are amplified. And a differential amplifier for detecting the output of the differential transformer. The fault detection device of the differential transformer of Patent Document 1 adjusts the reference point of the output of the differential amplifier so that the output of the differential amplifier when the differential transformer is disconnected and the differential transformer The output of the differential amplifier when it is not disconnected is made different. And it is comprised so that the failure by the disconnection of a differential transformer may be detected with the output of a differential amplifier.

Japanese Utility Model Publication No. 53-42727

  However, although the fault detection device for the differential transformer described in Patent Document 1 can detect the disconnection of the differential transformer, it is difficult to detect an abnormality of the differential transformer other than the disconnection. There is a problem.

  The present invention has been made to solve the above-described problems, and one object of the present invention is to provide a magnetism capable of detecting an abnormality other than the disconnection in addition to the disconnection abnormality of the magnetic substance inspection apparatus. It is to provide a physical examination device.

  In order to achieve the above object, a magnetic substance inspection apparatus according to an aspect of the present invention is a magnetic substance inspection apparatus for inspecting a magnetic substance, and includes an abnormality determination coil, a change in magnetic field of the magnetic substance, and an abnormality determination coil. A detection coil that detects a magnetic field and transmits a detection signal, and a control unit that inputs a predetermined current to the abnormality determination coil and determines the presence or absence of abnormality of the magnetic substance inspection apparatus based on the detection signal.

  In the magnetic substance inspection apparatus according to one aspect of the present invention, by configuring as described above, it is possible to give a change in the magnetic field to the detection coil by inputting a predetermined current to the abnormality determination coil. By acquiring a normal state of the change of the detection signal based on the change of the magnetic field in advance and comparing it with the actual change of the detection signal, it is possible to detect the abnormality of the magnetic substance inspection apparatus. Further, it is possible to detect an abnormality other than the disconnection of the detection coil. Thereby, abnormalities other than the disconnection of a magnetic substance inspection apparatus can be detected. Further, disconnection abnormality of the magnetic substance inspection apparatus can be detected from the degree of change of the detection signal. As a result, in addition to the disconnection abnormality of the magnetic substance inspection apparatus, it is possible to detect an abnormality other than the disconnection.

  The magnetic body inspection apparatus according to the above aspect preferably further includes an excitation coil for exciting the magnetization state of the magnetic body, and the control unit applies AC power synchronized with the excitation coil to the abnormality determination coil. It is configured to perform control to supply or control to supply DC power. If comprised in this way, since the change of the detection signal resulting from the change of the magnetic field by an abnormality determination coil can be made into a simple waveform, abnormality detection processing can be performed easily.

  In the magnetic substance inspection apparatus according to the above aspect, the detection coil preferably includes a pair of reception coils, includes a differential coil that transmits a differential signal, and the abnormality determination coil is provided in each of the pair of reception coils. On the other hand, a magnetic field is input. If comprised in this way, the change of the magnetic field by an abnormality determination coil can be output as a differential signal by a differential coil.

  In this case, preferably, the abnormality determination coil is arranged with a distance different from each other with respect to each of the pair of reception coils. If comprised in this way, the magnitude | size of the magnetic field input with respect to each receiving coil of a differential coil can mutually differ.

  In the magnetic substance inspection apparatus according to the above aspect, preferably, the control unit determines the presence / absence of abnormality of the magnetic substance inspection apparatus based on a change in the magnetic field with respect to the detection coil by the abnormality determination coil and a change amount of the detection signal. Is configured to do. If comprised in this way, since abnormality can be determined quantitatively based on the variation | change_quantity of a detection signal, the presence or absence of abnormality of a magnetic body test | inspection apparatus can be determined easily.

  In this case, preferably, the control unit obtains in advance a normal range of the change amount of the detection signal based on the change of the magnetic field with respect to the detection coil by the abnormality determination coil, and compares it with the change of the actual detection signal, It is configured to determine whether there is an abnormality in the magnetic substance inspection apparatus. If comprised in this way, the presence or absence of abnormality of a magnetic body test | inspection apparatus can be easily determined by determining whether the change of the detection signal resulting from the change of the magnetic field by an abnormality determination coil is in a normal range. it can.

  According to the present invention, as described above, in addition to the disconnection abnormality of the magnetic substance inspection apparatus, an abnormality other than the disconnection can be detected.

It is the schematic which shows the structure of the magnetic body test | inspection apparatus by one Embodiment. It is a block diagram which shows the control structure of the magnetic body test | inspection apparatus by one Embodiment. It is a figure for demonstrating the structure of the magnetic field application part and detection part of the magnetic body test | inspection apparatus by one Embodiment. It is the figure which showed an example of the detection signal in the case of abnormality determination of the magnetic body test | inspection apparatus by one Embodiment. It is a figure for demonstrating the structure of the magnetic field application part and detection part of the magnetic body test | inspection apparatus by the modification of one Embodiment.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments embodying the present invention will be described below with reference to the drawings.

  With reference to FIGS. 1-4, the structure of the magnetic body test | inspection apparatus 100 by this embodiment is demonstrated.

(Configuration of magnetic substance inspection device)
As shown in FIG. 1, the magnetic substance inspection apparatus 100 is configured to inspect a wire rope W that is an inspection object. The wire rope W is used for cranes, elevators, suspension bridges, robots, and the like. The magnetic body inspection device 100 is configured to inspect the wire rope W periodically. The magnetic body inspection apparatus 100 is configured to inspect the wire rope W for damage. The magnetic substance inspection apparatus 100 inspects the wire rope W while relatively moving along the surface of the wire rope W that is an inspection object. For example, when the wire rope W moves like a crane or an elevator, the inspection is performed with the movement of the wire rope W while the magnetic substance inspection device 100 is fixed. When the wire rope W does not move like a suspension bridge, the inspection is performed while moving the magnetic substance inspection device 100 along the wire rope W. The wire rope W is disposed so as to extend in the X direction at the position of the magnetic substance inspection apparatus 100. The wire rope W is an example of the “magnetic body” in the claims.

  As shown in FIG. 2, the magnetic substance inspection apparatus 100 includes a detection unit 1 and an electronic circuit unit 2. The detection unit 1 includes a differential coil 10 having a pair of receiving coils 11 and 12, an excitation coil 13, and an abnormality determination coil 14. The electronic circuit unit 2 includes a control unit 21, a reception I / F 22, an excitation I / F 23, an abnormality determination I / F 24, a power supply circuit 25, and a communication unit 26. The magnetic substance inspection apparatus 100 includes a magnetic field application unit 3 (see FIG. 3). The differential coil 10 is an example of the “detection coil” in the claims.

  An external device 200 is connected to the magnetic substance inspection device 100 via the communication unit 26. The external device 200 includes a communication unit 201, an analysis unit 202, and a display unit 203. The external device 200 is configured to receive measurement data of the wire rope W by the magnetic substance inspection device 100 via the communication unit 201. In addition, the external device 200 is configured to analyze the type of damage such as wire breakage and cross-sectional area change by the analysis unit 202 based on the received measurement data of the wire rope W. The external device 200 is configured to display the analysis result on the display unit 203.

  Specifically, the external device 200 is configured by a personal computer. The external device 200 is configured to instruct the generation of an abnormality determination signal by the abnormality determination coil 14 of the magnetic substance inspection device 100. In addition, the external device 200 is configured to receive a differential signal based on the abnormality determination signal and determine an operation state according to the magnitude of the received differential signal. The external device 200 is configured to output the determination result and display the result on the display unit 203.

  The wire rope W is formed by knitting (for example, strand knitting) a wire material having magnetism. The wire rope W is formed by a plurality of strands being combined. The wire rope W is a magnetic body made of a long material extending in the X direction. The wire rope W is monitored for state (presence or absence of scratches or the like) in order to prevent cutting due to deterioration. Then, the wire rope W whose deterioration has progressed from a predetermined amount is replaced.

  As shown in FIG. 3, the magnetic body inspection apparatus 100 is configured to detect a change in the magnetic field (magnetic flux) of the wire rope W.

  The magnetic field application unit 3 is configured to apply a magnetic field in the Y direction in advance to the wire rope W that is an inspection object to adjust the magnitude and direction of the magnetization of the magnetic material. The magnetic field application unit 3 includes a first magnetic field application unit including the magnets 31 and 32 and a second magnetic field application unit including the magnets 33 and 34. The first magnetic field application unit (magnets 31 and 32) is disposed on one side (X1 direction side) in the direction in which the wire rope W extends with respect to the detection unit 1. The second magnetic field application unit (magnets 33 and 34) is disposed on the other side (X2 direction side) in the direction in which the wire rope W extends with respect to the detection unit 1.

  As shown in FIG. 3, the differential coil 10 (receiving coils 11 and 12), the excitation coil 13, and the abnormality determination coil 14 are centered on the extending direction of the wire rope W that is a magnetic material made of a long material. As described above, each of the wires is wound a plurality of times along the longitudinal direction. The differential coil 10, the excitation coil 13, and the abnormality determination coil 14 are coils including a conductor portion that is formed to be cylindrical along the X direction (longitudinal direction) in which the wire rope W extends. Therefore, the surfaces formed by the conductive wire portions wound around the differential coil 10, the excitation coil 13, and the abnormality determination coil 14 are substantially orthogonal to the longitudinal direction. The wire rope W passes through the differential coil 10, the excitation coil 13, and the abnormality determination coil 14. The differential coil 10 is provided inside the excitation coil 13. The abnormality determination coil 14 is provided inside the excitation coil 13. In addition, arrangement | positioning of the differential coil 10, the excitation coil 13, and the abnormality determination coil 14 is not restricted to this. The receiving coil 11 of the differential coil 10 is disposed on the X1 direction side. The receiving coil 12 of the differential coil 10 is disposed on the X2 direction side.

  The abnormality determination coil 14 is arranged with a distance different from each other with respect to each of the pair of reception coils 11 and 12. Specifically, the abnormality determination coil 14 is disposed on the X1 direction side of the reception coil 11. That is, the abnormality determination coil 14 is disposed at a position closer to the receiving coil 11 among the receiving coils 11 and 12. The abnormality determination coil 14 and the reception coil 11 are spaced apart by a distance D1. In addition, the abnormality determination coil 14 and the reception coil 12 are spaced apart by a distance D2. However, D1 <D2. Further, the abnormality determination coil 14 is arranged so as to generate a magnetic field in the X direction. That is, the center axis of the abnormality determination coil 14 is arranged to be in the same direction as the center axes of the receiving coils 11 and 12.

  The excitation coil 13 excites the magnetization state of the wire rope W. Specifically, a configuration is such that a magnetic field generated based on the excitation AC current is applied along the X direction inside the excitation coil 13 when an excitation AC current is passed through the excitation coil 13.

  The differential coil 10 is configured to transmit a differential signal (detection signal) of the pair of receiving coils 11 and 12. Specifically, the differential coil 10 is configured to detect a change in the magnetic field of the wire rope W and transmit a differential signal. The differential coil 10 is configured to detect a change in the magnetic field in the X direction of the wire rope W that is an inspection target and output a detection signal (voltage). The differential coil 10 is configured to output a differential signal (voltage) based on the detected change in the magnetic field in the X direction of the wire rope W. Further, the differential coil 10 is arranged so that substantially all of the magnetic field generated by the excitation coil 13 can be detected (input). The differential coil 10 is configured to detect a magnetic field generated by the abnormality determination coil 14 and transmit a differential signal (detection signal).

  The abnormality determination coil 14 is configured to change the magnetic field with respect to the differential coil 10. Specifically, the abnormality determination coil 14 is configured to change the magnetic field input to the differential coil 10 when electric power is supplied when performing abnormality determination. Further, the abnormality determination coil 14 is configured to input magnetic fields having different sizes from each other to each of the pair of reception coils 11 and 12.

  When a defect (scratch or the like) exists in the wire rope W, the total magnetic flux (a value obtained by multiplying the magnetic field by the magnetic permeability and the area) becomes small in a portion having the defect (scratch or the like). As a result, for example, when the receiving coil 11 is located at a place where there is a defect (such as a scratch), the amount of magnetic flux passing through the receiving coil 12 changes as compared with the receiving coil 11, so that the detection voltage of the differential coil 10 The absolute value of the difference (differential signal) increases. On the other hand, the differential signal in a portion free from defects (such as scratches) is substantially zero. Thus, a clear signal (signal with a good S / N ratio) representing the presence of a defect (such as a scratch) is detected in the differential coil 10. Thereby, the electronic circuit unit 2 can detect the presence of a defect (such as a scratch) in the wire rope W based on the value of the differential signal.

  The control unit 21 of the electronic circuit unit 2 is configured to control each unit of the magnetic substance inspection apparatus 100. Specifically, the control unit 21 includes a processor such as a CPU (Central Processing Unit), a memory, an AD converter, and the like. The control unit 21 is configured to receive a differential signal from the differential coil 10 and detect the state of the wire rope W. The control unit 21 is configured to perform control for exciting the excitation coil 13. The control unit 21 is configured to supply power to the abnormality determination coil 14 to generate a magnetic field. The control unit 21 is configured to transmit the detection result of the state of the wire rope W to the external device 200 via the communication unit 26. The control unit 21 is configured to receive a differential signal via the reception I / F 22, perform A / D conversion, and acquire a signal by synchronous detection or a synchronous detection method.

  The reception I / F 22 is configured to receive the differential signal from the differential coil 10 and transmit it to the control unit 21. Specifically, the reception I / F 22 includes an amplifier. The reception I / F 22 is configured to amplify the differential signal of the differential coil 10 and transmit the amplified signal to the control unit 21.

  The excitation I / F 23 is configured to receive a signal from the control unit 21 and control the supply of power to the excitation coil 13. Specifically, the excitation I / F 23 controls the supply of power from the power supply circuit 25 to the excitation coil 13 based on a control signal from the control unit 21.

  The abnormality determination I / F 24 is configured to receive a signal from the control unit 21 and control power supply to the abnormality determination coil 14. Specifically, the abnormality determination I / F 24 controls power supply from the power supply circuit 25 to the abnormality determination coil 14 based on a control signal from the control unit 21.

  Here, in the present embodiment, the control unit 21 is configured to determine whether there is an abnormality in the magnetic body inspection apparatus 100 based on the change in the magnetic field applied to the differential coil 10 by the abnormality determination coil 14 and the detection signal. Has been. Specifically, the control unit 21 is configured to input a predetermined current to the abnormality determination coil 14 and determine the presence / absence of abnormality of the magnetic substance inspection apparatus 100 based on the detection signal. The control unit 21 is configured to determine whether there is an abnormality in the magnetic substance inspection apparatus 100 based on the change in the magnetic field applied to the differential coil 10 by the abnormality determination coil 14 and the amount of change in the detection signal. Moreover, the control part 21 is comprised so that the presence or absence of abnormality of the magnetic body test | inspection apparatus 100 may be determined based on whether the variation | change_quantity of a detection signal is in a predetermined range. Specifically, the control unit 21 acquires a normal range of the change amount of the detection signal based on the change of the magnetic field with respect to the differential coil 10 by the abnormality determination coil 14 in advance and compares it with the actual change of the detection signal. Thus, the magnetic substance inspection apparatus 100 is configured to determine whether or not there is an abnormality.

  As shown in FIG. 4, when performing the abnormality determination, the control unit 21 changes the power (current) supplied to the abnormality determination coil 14 from I0 to I1 at time t1. As a result, the magnetic field input to the receiving coil 11 and the receiving coil 12 of the differential coil 10 changes. As a result, at time t1, the differential signal changes from B0 to B1. When power is supplied to the abnormality determination coil 14, if the differential signal is B11 or more and B12 or less, it is determined that the state is normal. B11 and B12 are threshold values set with a predetermined width in consideration of noise. When power is supplied to the abnormality determination coil 14, if the differential signal is less than B11 or greater than B12, it is determined that an abnormal state has occurred. As the abnormality, there are circuit system failures such as disconnection or short circuit of the differential coil 10, disconnection or short circuit of the excitation coil 13. Also, an abnormality other than disconnection of the differential coil 10 or the like is detected. For example, an abnormality including the accuracy of the differential signal of the differential coil 10 is detected. Also, a failure of the electronic circuit is detected. Further, the control unit 21 is configured to determine whether or not the magnetic substance inspection apparatus 100 is operating normally from the magnitude of the change amount of the differential signal.

  In the present embodiment, the control unit 21 is configured to perform control for supplying AC power synchronized with the excitation coil 13 or control for supplying DC power to the abnormality determination coil 14. When supplying AC power synchronized with the excitation coil 13, the control unit 21 supplies power to the abnormality determination coil 14 by synchronizing the period of the excitation coil 13 and AC power.

  The abnormality determination is performed at the time of starting the magnetic substance inspection apparatus 100, before the inspection, or at regular intervals.

(Effect of this embodiment)
In the present embodiment, the following effects can be obtained.

  In the present embodiment, as described above, the abnormality determination coil 14 can change the magnetic field with respect to the differential coil 10, so that the normal state of the detection signal change based on the change of the magnetic field is acquired in advance. In addition, an abnormality of the magnetic substance inspection apparatus 100 can be detected by comparing with an actual change in the detection signal. Further, an abnormality other than the disconnection of the differential coil 10 can be detected. Thereby, abnormalities other than the disconnection of the magnetic substance inspection apparatus 100 can be detected. Further, disconnection abnormality of the magnetic body inspection apparatus 100 can be detected from the degree of change of the detection signal. As a result, in addition to the disconnection abnormality of the magnetic substance inspection apparatus 100, an abnormality other than the disconnection can be detected.

  In the present embodiment, as described above, the abnormality determination coil 14 is configured to input a magnetic field to each of the pair of reception coils 11 and 12. Thereby, the differential coil 10 can output the change in the magnetic field caused by the abnormality determination coil 14 as a differential signal.

  In the present embodiment, as described above, the control unit 21 performs control for supplying AC power synchronized with the excitation coil 13 or control for supplying DC power to the abnormality determination coil 14. Constitute. Thereby, since the change of the detection signal resulting from the change of the magnetic field by the abnormality determination coil 14 can be made into a simple waveform, the abnormality determination process can be easily performed.

  Further, in the present embodiment, as described above, the control unit 21 controls the abnormality of the magnetic substance inspection apparatus 100 based on the change of the magnetic field with respect to the differential coil 10 by the abnormality determination coil 14 and the change amount of the detection signal. It is configured to determine the presence or absence. Thereby, since abnormality can be determined quantitatively based on the variation | change_quantity of a detection signal, the presence or absence of abnormality of the magnetic body test | inspection apparatus 100 can be determined easily.

  In the present embodiment, as described above, the control unit 21 acquires in advance a normal range of the change amount of the detection signal based on the change in the magnetic field with respect to the differential coil 10 by the abnormality determination coil 14, By comparing with the change of the detection signal, it is configured to determine whether or not the magnetic body inspection apparatus 100 is abnormal. Thereby, the presence or absence of abnormality of the magnetic substance inspection apparatus 100 can be easily determined by determining whether or not the change of the detection signal caused by the change of the magnetic field by the abnormality determination coil 14 is within a normal range.

(Modification)
The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description of the embodiment but by the scope of claims, and further includes meanings equivalent to the scope of claims and all modifications (variants) within the scope.

  For example, in the above-described embodiment, the example in which the magnetic body to be inspected by the magnetic body inspection apparatus is a wire rope is shown, but the present invention is not limited to this. In the present invention, the magnetic body to be inspected by the magnetic body inspection apparatus may be a magnetic body other than the wire rope.

  In the above embodiment, the wire rope to be inspected is used for a crane, an elevator, a suspension bridge, a robot, and the like, but the present invention is not limited to this. In the present invention, the wire rope (magnetic body) to be inspected may be used other than a crane, an elevator, a suspension bridge, and a robot.

  Moreover, in the said one Embodiment, although the example of the structure by which the abnormality determination coil is arrange | positioned on one outer side of a pair of receiving coil was shown, this invention is not limited to this. In the present invention, as in the modification of the embodiment shown in FIG. 5, the abnormality determination coil may be provided between the pair of reception coils.

  Moreover, in the said one Embodiment, although the example of a structure with which a magnetic body test | inspection apparatus is provided with an excitation coil was shown, this invention is not limited to this. In the present invention, the magnetic substance inspection apparatus may not include the excitation coil.

  Moreover, in the said one Embodiment, although the magnetic substance inspection apparatus showed the example of a structure provided with a magnetic field application part, this invention is not limited to this. In the present invention, the magnetic substance inspection apparatus may not include the magnetic field application unit.

  Moreover, in the said one Embodiment, although the example of the structure to which the magnetic body test | inspection apparatus was connected to the external device was shown, this invention is not limited to this. In the present invention, the magnetic substance inspection device may be used independently without being connected to an external device.

  Moreover, in the said one Embodiment, although the example which comprises a detection coil by a differential coil was shown, this invention is not limited to this. In the present invention, the detection coil may be other than the differential coil.

10 Differential coil (detection coil)
DESCRIPTION OF SYMBOLS 11, 12 Reception coil 13 Excitation coil 14 Abnormality determination coil 21 Control part 100 Magnetic body inspection apparatus W Wire rope (magnetic body)

Claims (6)

A magnetic material inspection apparatus for inspecting a magnetic material,
An abnormality determination coil;
A detection coil that detects a change in the magnetic field of the magnetic material and a magnetic field generated by the abnormality determination coil and transmits a detection signal;
A magnetic substance inspection apparatus comprising: a control unit that inputs a predetermined current to the abnormality determination coil and determines whether or not the magnetic substance inspection apparatus is abnormal based on the detection signal. An excitation coil for exciting the magnetization state of the magnetic body;
2. The magnetism according to claim 1, wherein the control unit is configured to perform control for supplying AC power synchronized with the excitation coil or control for supplying DC power to the abnormality determination coil. Physical examination device. The detection coil has a pair of reception coils and includes a differential coil that transmits a differential signal;
The magnetic substance inspection apparatus according to claim 1, wherein the abnormality determination coil is configured to input a magnetic field to each of the pair of reception coils.   The said abnormality determination coil is a magnetic substance test | inspection apparatus of Claim 3 spaced apart by mutually different distance with respect to each of a pair of said receiving coils.   The said control part is comprised so that the presence or absence of abnormality of the said magnetic body test | inspection apparatus may be determined based on the change of the magnetic field with respect to the said detection coil by the said abnormality determination coil, and the variation | change_quantity of the said detection signal, Item 5. The magnetic substance inspection apparatus according to any one of Items 1 to 4.   The control unit acquires in advance a normal range of the change amount of the detection signal based on a change in the magnetic field with respect to the detection coil by the abnormality determination coil, and compares it with the actual change in the detection signal, The magnetic substance inspection apparatus according to claim 5, wherein the magnetic substance inspection apparatus is configured to determine whether there is an abnormality in the magnetic substance inspection apparatus.

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