JP7172135B2 - Magnetic inspection device - Google Patents

Description

TECHNICAL FIELD The present invention relates to a magnetic material inspection apparatus, and more particularly to a magnetic material inspection apparatus having a coil.

Conventionally, a device provided with a coil is known (see Patent Literature 1, for example).

The above Patent Document 1 discloses 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 that amplifies the differential signal of the differential transformer. and a differential amplifier that outputs a differential transformer fault detection apparatus. The failure detection device of the differential transformer of this 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 This is different from the output of the differential amplifier when there is no disconnection. The output of the differential amplifier is used to detect a failure due to disconnection of the differential transformer.

Japanese Utility Model Publication No. 53-42727

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

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and one object of the present invention is to provide a magnetic inspection apparatus capable of detecting not only disconnection abnormalities but also abnormalities other than disconnection in a magnetic material inspection apparatus. To provide a physical examination apparatus.

To achieve the above object, a magnetic material inspection apparatus according to one aspect of the present invention is a magnetic material inspection apparatus for inspecting a magnetic material extending in a predetermined direction, comprising an abnormality determination coil and A detection coil that is arranged in line with the abnormality determination coil and is wound so as to surround the magnetic material, detects changes in the magnetic field of the magnetic material and the magnetic field by the abnormality determination coil, and transmits a detection signal, and the abnormality determination coil. a control unit that inputs a predetermined current and determines whether or not there is an abnormality in the magnetic material inspection device based on the detection signal;

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

The magnetic material inspection apparatus according to the above aspect preferably further includes an excitation coil for exciting the state of magnetization of the magnetic material, and the control unit applies AC power to the abnormality determination coil in synchronization with the excitation coil. It is configured to perform control of supply or control of supply of DC power. With this configuration, the change in the detection signal caused by the change in the magnetic field of the abnormality determination coil can be made into a simple waveform, so that the abnormality detection process can be easily performed.

In the magnetic material inspection apparatus according to the above aspect, preferably, the detection coil has a pair of receiving coils, includes a differential coil that transmits a differential signal, and the abnormality determination coil is connected to each of the pair of receiving coils. On the other hand, it is configured to input a magnetic field. With this configuration, the differential coil can output the change in the magnetic field caused by the abnormality determination coil as a differential signal.

In this case, preferably, the abnormality determination coils are separated from each of the pair of receiving coils by different distances. With this configuration, the magnitude of the magnetic field input to each receiving coil of the differential coil can be made different from each other.

In the magnetic material inspection apparatus according to the above aspect, preferably, the control unit determines whether there is an abnormality in the magnetic material inspection apparatus based on a change in the magnetic field of the detection coil by the abnormality determination coil and a change in the detection signal. is configured to With this configuration, it is possible to quantitatively determine an abnormality based on the amount of change in the detection signal, so it is possible to easily determine whether or not there is an abnormality in the magnetic material inspection apparatus.

In this case, preferably, the control unit acquires in advance the normal range of the amount of change in the detection signal based on the change in the magnetic field of the detection coil by the abnormality determination coil, and compares it with the actual change in the detection signal. It is configured to determine whether or not there is an abnormality in the magnetic material inspection device. With this configuration, it is possible to easily determine whether or not there is an abnormality in the magnetic material inspection apparatus by determining whether or not the change in the detection signal due to the change in the magnetic field by the abnormality determination coil is within a normal range. can.

According to the present invention, as described above, it is possible to detect an abnormality other than disconnection in addition to the disconnection abnormality of the magnetic material inspection apparatus.

1 is a schematic diagram showing the configuration of a magnetic material inspection apparatus according to one embodiment; FIG. It is a block diagram showing a control configuration of the magnetic body inspection apparatus according to one embodiment. It is a figure for demonstrating the structure of the magnetic field application part of the magnetic material inspection apparatus by one Embodiment, and a detection part. It is the figure which showed an example of the detection signal at the time of the 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 of the magnetic material inspection apparatus by the modification of one Embodiment, and a detection part.

Embodiments embodying the present invention will be described below with reference to the drawings.

A configuration of a magnetic material inspection apparatus 100 according to the present embodiment will be described with reference to FIGS. 1 to 4. FIG.

(Configuration of magnetic material inspection device)
As shown in FIG. 1, the magnetic material inspection apparatus 100 is configured to inspect a wire rope W, which is an object to be inspected. Wire ropes W are used for cranes, elevators, suspension bridges, robots, and the like. The magnetic material inspection device 100 is configured to inspect the wire rope W periodically. The magnetic body inspection device 100 is configured to inspect the wire rope W for damage. The magnetic material inspection apparatus 100 inspects the wire rope W while relatively moving along the surface of the wire rope W, which is an inspection object. For example, when the wire rope W moves, such as in a crane or an elevator, inspection is performed as the wire rope W moves while the magnetic material inspection device 100 is fixed. Moreover, when the wire rope W does not move like a suspension bridge, inspection is performed while moving the magnetic material inspection apparatus 100 along the wire rope W. The wire rope W is arranged so as to extend in the X direction at the position of the magnetic material inspection device 100 . The wire rope W is an example of the "magnetic body" in the scope of claims.

The magnetic material inspection apparatus 100 includes a detection section 1 and an electronic circuit section 2, as shown in FIG. 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 . The electronic circuit section 2 includes a control section 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 section 26 . The magnetic material inspection apparatus 100 also 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 material inspection device 100 via the communication unit 26 . The external device 200 includes a communication section 201 , an analysis section 202 and a display section 203 . The external device 200 is configured to receive measurement data of the wire rope W by the magnetic material inspection device 100 via the communication unit 201 . Further, the external device 200 is configured to analyze the type of damage such as wire breakage and change in cross-sectional area by the analysis unit 202 based on the received measurement data of the wire rope W. The external device 200 is also 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 also configured to instruct the abnormality determination coil 14 of the magnetic material inspection apparatus 100 to generate an abnormality determination signal. Further, the external device 200 is configured to receive a differential signal based on the abnormality determination signal and determine the operating state according to the magnitude of the received differential signal. The external device 200 is also configured to output the determination result and display the result on the display unit 203 .

The wire rope W is formed by weaving (for example, strand weaving) a magnetic wire material. Moreover, the wire rope W is formed by twisting a plurality of strands. 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 its condition (presence or absence of scratches, etc.) in order to prevent breakage due to deterioration. Then, the wire rope W whose deterioration has progressed beyond a predetermined amount is replaced.

As shown in FIG. 3, the magnetic material inspection device 100 is configured to detect changes in the magnetic field (magnetic flux) of the wire rope W. As shown in FIG.

The magnetic field applying unit 3 is configured to apply a magnetic field in advance in the Y direction to the wire rope W, which is an object to be inspected, to adjust the magnitude and direction of magnetization of the magnetic material. The magnetic field applying section 3 includes a first magnetic field applying section including magnets 31 and 32 and a second magnetic field applying section including magnets 33 and 34 . The first magnetic field applying section (magnets 31 and 32) is arranged on one side (X1 direction side) of the detecting section 1 in the direction in which the wire rope W extends. Further, the second magnetic field applying section (magnets 33 and 34) is arranged on the other side (the X2 direction side) of the direction in which the wire rope W extends with respect to the detecting section 1 .

The differential coil 10 (receiving coils 11 and 12), the excitation coil 13, and the abnormality determination coil 14, as shown in FIG. , are wound a plurality of times along the longitudinal direction. Further, the differential coil 10, the excitation coil 13, and the abnormality determination coil 14 are coils including conductor portions that are cylindrically formed along the X direction (longitudinal direction) in which the wire rope W extends. Therefore, the planes formed by the wire portions around which the differential coil 10, the excitation coil 13, and the abnormality determination coil 14 are wound are substantially perpendicular to the longitudinal direction. The wire rope W passes through the insides of the differential coil 10 , the excitation coil 13 and the abnormality determination coil 14 . Also, the differential coil 10 is provided inside the excitation coil 13 . Further, the abnormality determination coil 14 is provided inside the excitation coil 13 . Note that the arrangement of the differential coil 10, the excitation coil 13, and the abnormality determination coil 14 is not limited to this. The receiving coil 11 of the differential coil 10 is arranged on the X1 direction side. Also, the receiving coil 12 of the differential coil 10 is arranged on the X2 direction side.

Abnormality determination coil 14 is arranged apart from each of the pair of receiving coils 11 and 12 by different distances. Specifically, the abnormality determination coil 14 is arranged on the X1 direction side of the receiving coil 11 . That is, of the receiving coils 11 and 12, the abnormality determination coil 14 is arranged at a position closer to the receiving coil 11. As shown in FIG. Abnormality determination coil 14 and receiving coil 11 are arranged apart from each other by distance D1. Moreover, the abnormality determination coil 14 and the receiving coil 12 are arranged apart from each other 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. In other words, the central axis of abnormality determination coil 14 is arranged in the same direction as the central axes of receiving coils 11 and 12 .

The excitation coil 13 excites the magnetization state of the wire rope W. As shown in FIG. Specifically, when an exciting alternating current is supplied to the exciting coil 13, a magnetic field generated based on the exciting alternating current is applied inside the exciting coil 13 along the X direction.

Differential coil 10 is configured to transmit a differential signal (detection signal) of a 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 of the wire rope W, which is an object to be inspected, in the X direction and output a detection signal (voltage). The differential coil 10 is also configured to output a differential signal (voltage) based on the detected change in the magnetic field of the wire rope W in the X direction. 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 also configured to detect the 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 be supplied with electric power and change the magnetic field input to the differential coil 10 when performing abnormality determination. Further, the abnormality determination coil 14 is configured to input magnetic fields having different magnitudes to each of the pair of receiving coils 11 and 12 .

If the wire rope W has a defect (such as a flaw), the total magnetic flux (a value obtained by multiplying the magnetic field by the magnetic permeability and the area) of the wire rope W is reduced at the defective portion (such as the flaw). As a result, for example, when the receiving coil 11 is positioned at a location with a defect (such as a scratch), the amount of magnetic flux passing through the receiving coil 12 changes compared to that of the receiving coil 11, so that the voltage detected by the differential coil 10 changes. The absolute value of the difference (differential signal) increases. On the other hand, the differential signal is substantially zero in a portion without defects (scratches, etc.). Thus, in the differential coil 10, a clear signal (a signal with a good S/N ratio) representing the presence of defects (scratches, etc.) is detected. Thereby, the electronic circuit section 2 can detect the presence of a defect (such as a flaw) in the wire rope W based on the value of the differential signal.

The control section 21 of the electronic circuit section 2 is configured to control each section of the magnetic material 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 detect the state of the wire rope W by receiving the differential signal of the differential coil 10 . Further, the control unit 21 is configured to perform control to excite the excitation coil 13 . Further, the control unit 21 is configured to supply electric power to the abnormality determination coil 14 to generate a magnetic field. The control unit 21 is also configured to transmit the detection result of the state of the wire rope W to the external device 200 via the communication unit 26 . Also, the control unit 21 is configured to receive a differential signal via the reception I/F 22, perform A/D conversion, and obtain 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 section 21 . Specifically, the reception I/F 22 includes an amplifier. Further, the reception I/F 22 is configured to amplify the differential signal of the differential coil 10 and transmit it to the control section 21 .

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

The abnormality determination I/F 24 is configured to receive a signal from the control section 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 the 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 material inspection device 100 based on the change in the magnetic field of the differential coil 10 by the abnormality determination coil 14 and the detection signal. It is Specifically, the control unit 21 is configured to input a predetermined current to the abnormality determination coil 14 and determine whether or not there is an abnormality in the magnetic material inspection apparatus 100 based on the detection signal. The control unit 21 is configured to determine whether or not there is an abnormality in the magnetic material inspection device 100 based on the change in the magnetic field of the differential coil 10 by the abnormality determination coil 14 and the amount of change in the detection signal. Further, the control unit 21 is configured to determine whether or not there is an abnormality in the magnetic material inspection device 100 based on whether or not the amount of change in the detection signal is within a predetermined range. Specifically, the control unit 21 acquires in advance the normal range of the amount of change in the detection signal based on the change in the magnetic field of the differential coil 10 by the abnormality determination coil 14, and compares it with the actual change in the detection signal. Thus, the presence or absence of abnormality in the magnetic material inspection device 100 is determined.

As shown in FIG. 4, when carrying out 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 greater than or equal to B11 and less than or equal to B12, it is determined that the state is normal. B11 and B12 are threshold values 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 abnormality has occurred. The abnormalities include circuit system failures such as disconnection and short circuit of the differential coil 10 and disconnection and 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, electronic circuit failures are detected. Further, the control unit 21 is configured to determine whether or not the magnetic material inspection device 100 is operating normally based on the amount of change in the differential signal.

Further, in the present embodiment, the control unit 21 is configured to perform control to supply AC power synchronized with the excitation coil 13 or control to supply DC power to the abnormality determination coil 14 . When supplying AC power synchronized with the excitation coil 13 , the control unit 21 synchronizes the cycle of the AC power with the excitation coil 13 and supplies power to the abnormality determination coil 14 .

Further, the abnormality determination is performed regularly at every predetermined time, such as when the magnetic material inspection apparatus 100 is started, before inspection, and so on.

(Effect of this embodiment)
The following effects can be obtained in this embodiment.

In this embodiment, as described above, the abnormality determination coil 14 can apply a change in the magnetic field to the differential coil 10, so that the normal state of the change in the detection signal based on the change in the magnetic field can be acquired in advance. By comparing it with the change in the actual detection signal, an abnormality of the magnetic material inspection apparatus 100 can be detected. In addition, abnormalities other than disconnection of the differential coil 10 can be detected. Thereby, abnormalities other than disconnection of the magnetic material inspection apparatus 100 can be detected. Moreover, the disconnection abnormality of the magnetic material inspection apparatus 100 can also be detected from the degree of change in the detection signal. As a result, in addition to disconnection abnormality of the magnetic material inspection apparatus 100, abnormality other than disconnection can also be detected.

Further, in this embodiment, as described above, the abnormality determination coil 14 is configured to input a magnetic field to each of the pair of receiving coils 11 and 12 . As a result, the differential coil 10 can output the change in the magnetic field generated by the abnormality determination coil 14 as a differential signal.

Further, in the present embodiment, as described above, the control unit 21 is controlled to supply AC power synchronized with the excitation coil 13 or to supply DC power to the abnormality determination coil 14. Configure. As a result, the change in the detection signal caused by the change in the magnetic field of the abnormality determination coil 14 can be made into a simple waveform, so that the abnormality determination process can be easily performed.

Further, in the present embodiment, as described above, the controller 21 detects an abnormality of the magnetic material inspection apparatus 100 based on the change in the magnetic field of the abnormality determination coil 14 with respect to the differential coil 10 and the amount of change in the detection signal. It is configured to determine the presence/absence. As a result, it is possible to quantitatively determine an abnormality based on the amount of change in the detection signal, so it is possible to easily determine whether or not there is an abnormality in the magnetic material inspection apparatus 100 .

Further, in the present embodiment, as described above, the control unit 21 acquires in advance the normal range of the change amount of the detection signal based on the change in the magnetic field of the differential coil 10 by the abnormality determination coil 14, and the actual range is obtained. It is configured to determine whether or not there is an abnormality in the magnetic material inspection apparatus 100 by comparing with the change in the detection signal. Accordingly, it is possible to easily determine whether or not there is an abnormality in the magnetic material inspection apparatus 100 by determining whether or not the change in the detection signal caused by the change in the magnetic field of the abnormality determination coil 14 is within a normal range.

(Modification)
It should be noted that the embodiments disclosed this time should be considered as examples and not restrictive in all respects. The scope of the present invention is indicated by the scope of the claims rather than the above description of the embodiments, and includes all modifications (modifications) within the meaning and scope equivalent to the scope of the claims.

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

Moreover, although the wire ropes to be inspected are used in cranes, elevators, suspension bridges, robots, and the like in the above embodiment, the present invention is not limited to this. In the present invention, the wire rope (magnetic material) to be inspected may be used for cranes, elevators, suspension bridges, and robots.

Further, in the above embodiment, an example of a configuration in which the abnormality determination coil is arranged outside one of the pair of receiving coils has been shown, but the present 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 receiving coils.

Moreover, although the magnetic material inspection apparatus showed the example of a structure provided with an excitation coil in said one Embodiment, this invention is not limited to this. In the present invention, the magnetic material inspection device does not have to have an excitation coil.

Further, in the above-described embodiment, an example of a configuration in which the magnetic material inspection device includes the magnetic field application unit has been described, but the present invention is not limited to this. In the present invention, the magnetic material inspection device does not have to include the magnetic field applying section.

Further, in the above embodiment, an example of a configuration in which the magnetic material inspection device is connected to an external device was shown, but the present invention is not limited to this. In the present invention, the magnetic material inspection device may be used independently without being connected to an external device.

Also, in the above-described embodiment, an example in which the detection coil is configured by a differential coil has been shown, but the present invention is not limited to this. In the present invention, the sensing coil may be other than a differential coil.

10 differential coil (detection coil)
Reference Signs List 11, 12 receiving coil 13 excitation coil 14 abnormality determination coil 21 control unit 100 magnetic material inspection device W wire rope (magnetic material)

Claims (6)

A magnetic body inspection device for inspecting a magnetic body extending in a predetermined direction ,
an abnormality determination coil;
It is arranged along the predetermined direction along the abnormality determination coil and is wound so as to surround the magnetic body, and detects a change in the magnetic field of the magnetic body and the magnetic field by the abnormality determination coil to generate a detection signal. a sensing coil that transmits
a control unit that inputs a predetermined current to the abnormality determination coil and determines whether or not there is an abnormality in the magnetic material inspection apparatus based on the detection signal. Further comprising an excitation coil for exciting the state of magnetization of the magnetic material,
The magnetism according to claim 1, wherein the control unit is configured to perform control to supply AC power synchronized with the excitation coil or control to supply DC power to the abnormality determination coil. physical examination equipment. The sensing coil includes a differential coil that has a pair of receiving coils and transmits a differential signal,
3. The magnetic material inspection apparatus according to claim 1, wherein said abnormality determination coil is configured to input a magnetic field to each of said pair of receiving coils. 4. The magnetic material inspection apparatus according to claim 3, wherein said abnormality determination coil is arranged to be separated from each of said pair of receiving coils by distances different from each other. The control unit is configured to determine whether or not there is an abnormality in the magnetic material inspection device based on a change in the magnetic field of the detection coil by the abnormality determination coil and a variation in the detection signal. Item 5. The magnetic material inspection device according to any one of Items 1 to 4. The control unit acquires in advance a normal range of the amount of change in the detection signal based on the change in the magnetic field of the detection coil by the abnormality determination coil, and compares it with the actual change in the detection signal to determine the 6. The magnetic material inspection device according to claim 5, configured to determine whether or not there is an abnormality in the magnetic material inspection device.

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