JP5574809B2 - Wire rope flaw detector and detection method using wire rope flaw detector - Google Patents

Description

  The present invention is a wire rope flaw detector capable of detecting breakage of a wire rope that suspends a passenger car such as an elevator or wire breakage (hereinafter referred to as a wire rope damaged portion), and detection using the wire rope flaw detector. It is about the method.

  In conventional wire rope flaw detectors, the magnetizer is composed of a permanent magnet or electromagnet (hereinafter referred to as a magnet) and a magnetic path member such as a back yoke for magnetically connecting them, and is attached to the wire rope. When this is done, the magnet, the magnetic path member such as the back yoke, and the wire rope form a closed loop of the ferromagnetic material, and most of the magnetic flux generated by the magnet passes through this closed loop of the ferromagnetic material. However, there is also a magnetic flux leaking from this ferromagnetic loop. This type of leakage magnetic flux exists regardless of the presence or absence of a rope damaged portion, and if these pass through the magnetic sensor, the magnetic sensor may malfunction. Therefore, it is necessary to design the magnetizer so that the magnetic flux density near the magnetic sensor is as low as possible. According to the relationship between the magnetic flux density at the sensor position when the distance between the sensor and the magnet is changed with the magnet material and size being constant in the magnetizer without damage to the rope, It is clear that it is effective to dispose the magnet at a location sufficiently away from the magnet. Therefore, the optimum distance varies depending on the type of magnet used, the type of sensor, the rope diameter, etc., but is usually set to 2.5 times or more (see, for example, Patent Document 1).

JP 2005-154042 A

  In the conventional wire rope flaw detector, if the distance between the magnet and the sensor is increased, the volume of the back yoke increases. Since the constituent element of the back yoke is mainly iron, the mass increases as the volume of the back yoke increases. Furthermore, when magnetizers are arranged in parallel to simultaneously inspect a plurality of wire ropes, the mass of the entire inspector is greatly increased because the mass of the magnets is added in addition to the number of magnetizers. The wire rope inspection work is carried out in the machine room or the hoistway, and the work space is generally a narrow space, and the handling of heavy objects in the space is physically burdensome for the inspection worker. There was a problem that the work efficiency was reduced.

  The present invention has been made to solve the above problems, and provides a wire rope flaw detector capable of easily and simultaneously inspecting a plurality of wire ropes and a detection method using the wire rope flaw detector. For the purpose.

The present invention provides a wire rope flaw detector for detecting a damaged portion of any one of a plurality of wire ropes.
First and second passage portions serving as wire rope passages spaced apart in a direction perpendicular to the longitudinal direction of the wire rope;
A first magnet disposed between the first passage portion and the second passage portion;
A second magnet disposed between the first passage portion and the second passage portion and separated in the longitudinal direction of the first magnet and the wire rope and in a magnetic pole direction different from the magnetic pole direction of the first magnet;
A magnetic sensor disposed between the first magnet and the second magnet,
When different wire ropes are respectively disposed on the first and second passage portions, a closed loop is formed by the wire ropes and the first and second magnets,
The magnetic sensor detects a damaged portion of the wire rope by detecting a magnetic flux other than the magnetic flux flowing through the closed loop.

Since the induction heating device of the present invention is configured as described above,
An increase in temperature of the induction heating coil can be suppressed.

It is a figure which shows the structure of the wire rope flaw detector of Embodiment 1 of this invention. It is a figure which shows a structure when the wire rope flaw detector shown in FIG. 1 is mounted | worn with a wire rope. It is a schematic diagram which shows the magnetic path formed when a wire rope is arrange | positioned to the wire rope deep wound device shown in FIG. In a wire rope flaw detector, it is a figure which shows the relationship with the leakage magnetic flux density produced irrespective of the presence or absence of a disconnection when changing the distance of a magnet and a magnetic sensor. It is a figure which shows the structure of the wire rope flaw detector of Embodiment 2 of this invention. It is a figure for demonstrating the detection method using the wire rope flaw detector of Embodiment 2 of this invention. It is a figure for demonstrating the detection method using the wire rope flaw detector of Embodiment 3 of this invention.

Embodiment 1 FIG.
Embodiments of the present invention will be described below. 1 is a perspective view showing a configuration of a wire rope flaw detector according to Embodiment 1 of the present invention, and FIG. 1 (b) is an exploded perspective view of FIG. 1 (a). 2 is an external view showing a state in which the wire rope flaw detector shown in FIG. 1 is attached to the wire rope, FIG. 3 is a schematic diagram of a magnetic path formed in the state shown in FIG. 2, and FIG. 4 is a magnetic sensor and a magnet. It is the figure which showed the relationship between the distance to and the diameter of a wire rope. In the figure, a wire rope flaw detector 2 for detecting a damaged portion of the first and second wire ropes 21 and 22 is provided with a first and second wire ropes 21 and 22 that are spaced apart from each other. Two passage portions 13 and 14 are provided. The 1st and 2nd channel | path parts 13 and 14 here refer to the part which the 1st and 2nd wire ropes 21 and 22 can pass.

  And it is arrange | positioned between the 1st channel | path part 13 and the 2nd channel | path part 14, for example between the 1st magnet part 31 which consists of a permanent magnet or an electromagnet, and the 1st channel | path part 13 and the 2nd channel | path part 14. The first magnet 31 is separated from the first magnet 31 in the longitudinal direction and is arranged in a magnetic pole direction different from the magnetic pole direction of the first magnet 31, and for example, a second magnet 32 made of a permanent magnet or an electromagnet, the first magnet 31 and the second magnet. And a magnetic sensor 5 disposed between the magnet 32 and the magnet 32. The magnetic sensor 5 includes a first sensor portion 51 formed at a position adjacent to the first passage portion 13 and a second sensor portion 52 formed at a position adjacent to the second passage portion 14. Yes.

  The magnetic sensor 5 is for detecting the leakage magnetic flux 12 by detecting the leakage magnetic flux 12 as a magnetic flux other than the magnetic flux 10 flowing in the closed loop described below generated from the vicinity of the damaged portion 11, and detects the leakage magnetic flux 12. However, since the change in magnetic flux density due to the leakage magnetic flux 12 is generally several to several tens of mT, a coil, a Hall element, etc. are suitable. Yes. In addition, as shown in FIG. 4, the position between the first magnet 31 and the second magnet 32 where the magnetic sensor 5 is installed is “the distance L between the magnetic sensor and the magnet (see L in FIG. 3). ) ”And“ the diameter d of the wire rope (see d in FIG. 3) ”and the leakage magnetic flux density (refers to the leakage magnetic flux that becomes noise in the detection generated from the magnet, not the damaged portion) If the distance between the magnetic sensor and the magnet is too short, the magnetic sensor may detect a leakage magnetic flux that causes noise, which may lead to erroneous detection. It is necessary to set the distance L between the first and second magnets 31 and 32.

  And the 1st interpolation part 41 formed to the 1st pole side here of the 1st magnet 31 here N pole side, and reaching to the 1st passage part 13 and the 2nd pole side here of the 1st magnet 31 Close to the S pole side and close to the second pole portion 42 on the second pole side of the second magnet 32 and the second interpolation portion 42 formed until reaching the second passage portion 14 and on the first passage portion 13. A third interpolation unit 43 formed up to the first pole side, and a fourth interpolation unit 44 formed in close contact with the N pole side of the first pole side of the second magnet 32 and up to the second passage unit 14. Yes. The first to fourth interpolation units 41, 42, 43, and 44 are formed of a ferromagnetic material such as iron. And these 1st thru | or 4th interpolation parts 41, 42, 43, and 44 are formed in the cross-sectional L-shape, the 1st and 2nd magnets 31 and 32, the 1st and 2nd channel | path part 13, 14, the first and second magnets 31, 32 are moved from the sliding movement of the first and second wire ropes 21, 22. Further, the magnetic resistance between the first and second wire ropes 21 and 22 and the first and second magnets 31 and 32 is lowered while being protected, and the first and second wire ropes 21 and 22 are efficient. It is formed to inject the magnetic flux 10 into the magnetic field.

  The first and second passage portions 13 and 14, the first and second magnets 31 and 32, and the magnetic sensor 5 are fixedly disposed on one surface of the base plate 8 as a transport portion, respectively. The base plate 8 is formed so as to be integrally movable in the longitudinal direction of the first and second wire ropes 21 and 22. The base plate 8 is made of a non-magnetic material, and is formed of a lightweight material typified by wood or aluminum, for example. Further, on one surface of the base plate 8, there is provided a fixed base 6 for disposing the magnetic sensor 5 at a distance close to the first and second wire ropes 21 and 22. The fixing base 6 is made of a non-magnetic material. For example, aluminum, austenitic stainless steel, brass, resin, wood, or the like having a sufficient strength may be used, but the magnetic sensor 5 is formed of a coil. If it is used, a resin such as bakelite is preferable from the viewpoint of insulation.

  And the cover 7 for protecting the magnetic sensor 5 from sliding of the 1st and 2nd wire ropes 21 and 22 is provided. The cover 7 is made of a non-magnetic material and has sufficient strength even when the wire ropes 21 and 22 are repeatedly slid by contact, such as aluminum, austenitic stainless steel, brass, and resin. I just need it. On the other side of the base plate 8, a handle 9 is formed for the inspection operator to hold and move the base plate 8. The handle 9 may be formed of the same material as that of the base plate 8, and the thickness of the base plate 8 may be the first and second magnets 31 and 32 and the first to fourth interpolation units 41, 42, 43, The thickness is not limited to this as long as it can be magnetically insulated from 44. When the first and second wire ropes 21 and 22 are disposed on the first and second passage portions 13 and 14, respectively, the first and second wire ropes 21 and 22 and the first and second magnets 31 are provided. , 32 and the first to fourth interpolation units 41, 42, 43, 44 form a closed loop. Therefore, the virtual plane of the closed loop formed in this way and the virtual plane including the central axes of the two first and second wire ropes 21 and 22 are configured to be substantially parallel. The “closed loop” referred to here does not necessarily mean that the first and second wire ropes 21 and 22, the first and second magnets 31 and 32, and the first to fourth interpolation units 41, 42, 43, and 44, respectively. Even if it is not in close contact, a gap that generates magnetic flux is included.

  Next, the operation of the wire rope flaw detector according to Embodiment 1 configured as described above will be described. First, as shown in FIG. 2, the wire rope flaw detector 2 is provided with first and second wire ropes 21 and 22 on the first and second passage portions 13 and 14. And it uses it in the state made to contact the 2nd channel | path parts 13 and 14. FIG. Then, by moving the first and second wire ropes 21 and 22 relative to the wire rope flaw detector 2, the inspection is sequentially performed in the longitudinal direction of the first and second wire ropes 21 and 22. Here, the flow of the magnetic flux 10 will be described with reference to FIG. The magnetic flux generated by the first magnet 31 flows into the first wire rope 21 via the first auxiliary portion 41. Then, it flows out through the third interpolation unit 43, passes through the second magnet 32, and flows into the second wire rope 22 through the fourth interpolation unit 44. Finally, the process returns to the first magnet 31 via the second interpolation unit 42. Further, the magnetic flux generated by the second magnet 43 returns to the second magnet 43 through the same process. For example, when the damaged portion 11 exists in the first wire rope 21, a part of the magnetic flux 10 leaks to the outside of the first wire rope 21 in the vicinity thereof, and the leakage magnetic flux 12 is generated. By detecting the leakage magnetic flux 12 by the first sensor unit 51, it is possible to know the presence or absence of damage.

  According to the wire rope flaw detector of Embodiment 1 configured as described above, the wire rope occupies the magnetic circuit by adopting a configuration in which two wire ropes are included in one magnetic circuit. As the ratio increases, the amount of magnetic material other than the wire rope and magnet decreases, and the amount of magnetic path member used per wire rope is greatly reduced compared to the conventional case. Weight can be reduced. Moreover, in the wire rope flaw detector applied to the prior art, two magnets are used per wire rope. However, in the first embodiment, the amount of magnet used is one when converted per wire rope. The manufacturing cost can be reduced.

  In addition, the leakage flux as noise other than the magnetic flux that flows in the closed loop regardless of whether the wire rope is damaged or not, ensures a sufficient distance between the magnet and the magnetic sensor in order to reduce the magnetic flux density that passes near the magnetic sensor. Although it is necessary, in the present invention, even if the distance between the magnet and the magnetic sensor is extended in the wire rope longitudinal direction, the amount of magnetic material used does not increase. Therefore, it is possible to achieve both improvement in detection accuracy and weight reduction of the wire rope flaw detector. The weight reduction facilitates the handling of the wire rope flaw detector and improves the workability of inspection.

  In the first embodiment, an example using two wire ropes has been described. However, when flaw detection using only one wire rope is performed, a magnetic member such as iron is provided in any one of the passage portions. It is possible to perform flaw detection by holding a pipe and forming a magnetic path in the same manner as in the first embodiment.

  In the first embodiment, the example including the first to fourth interpolation units has been described. However, the present invention is not limited to this, and the first and fourth interpolation units may be provided without including the first to fourth interpolation units. When the first and second wire ropes are respectively disposed on the two passage portions, a closed loop can be formed by the first and second wire ropes and the first and second magnets, and the magnetic flux flowing in the closed loop If the magnetic flux other than is detected by the magnetic sensor, the same effects as those of the first embodiment can be obtained. Further, even if all the first to fourth interpolation units are not provided, only necessary portions may be provided.

  Moreover, although the example comprised with a 1st sensor and a 2nd sensor was shown as a magnetic sensor, it is not restricted to this, You may make it provide only any one of a 1st sensor or a 2nd sensor. . In that case, only the damage of either the first or second wire rope is searched, but the flaw detection of both the first and second wire ropes can be performed by reversing the direction and moving the longitudinal direction of the wire rope. This can be performed in the same manner as in the first embodiment.

  In addition, the base plate 8 is shown as an example of the conveyance unit, but the present invention is not limited to this, and the first and second passage portions 13 and 14, the first and second magnets 31, even in other shapes, 32 and the magnetic sensor 5 can be performed in the same manner as in the first embodiment as long as the shape is movable in the longitudinal direction of the first and second wire ropes 21 and 22 and is a nonmagnetic material. .

Embodiment 2. FIG.
5 is a view showing the configuration of a wire rope flaw detector according to Embodiment 2 of the present invention. FIG. 5 (b) is an AA cross section of FIG. 5 (a), and FIG. 5 (b) is a BB cross section. FIG. 5 (c) shows a CC cross section. In the figure, the same parts as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted. Here, the first interpolation unit 45, the second interpolation unit 46, the third interpolation 47 unit, and the fourth interpolation unit 48 are opened on the insertion side of the first and second wire ropes 21 and 22, here the upper surface is opened. The first and second wire ropes 21 and 22 are formed in a concave cross section so as to surround the side surfaces. Further, the first sensor portion 53 and the second sensor portion 54 of the magnetic sensor 5 are opened on the insertion side, here the upper surface, of the first and second wire ropes 21 and 22, and the first and second wire ropes 21 and 22 are opened. For example, a search coil is formed in a concave cross section so as to surround the side surface.

  By performing the operation of the wire rope flaw detector of the second embodiment configured as described above in the same manner as in the first embodiment, the flaw detection of the first and second wire ropes 21 and 22 can be performed. In this case, the first to fourth interpolation units 45, 46, 47, 48 and the first and second sensor units 53, 54 are formed so as to surround the side surfaces of the first and second wire ropes 21, 22. Therefore, the detection range of the flaw detection can be improved because the capture range of the leakage magnetic flux can be expanded.

  In the second embodiment, the example in which the first to fourth interpolation portions and the first and second sensor portions are formed in the concave shape of the cross section is shown. However, the present invention is not limited to this, and the second wire If the rope can be inserted and is formed so as to surround the side surfaces of the first and second wire ropes, the same effect can be obtained. Moreover, although the example which comprised the 1st sensor part and the 2nd sensor part with one search coil was shown, it is not restricted to this, It is also possible to comprise with the search coil which divided | segmented one sensor part. It is.

Embodiment 3 FIG.
FIG. 6 is a view for explaining a detection method using a wire rope flaw detector according to Embodiment 3 of the present invention. In the figure, the same parts as those in the above embodiments are denoted by the same reference numerals, and description thereof is omitted. In each of the above-described embodiments, the case where flaw detection is performed on two wire ropes has been described. In this third embodiment, a case where flaw detection is performed on four wire ropes will be described. Two wire rope flaw detectors shown in the first embodiment are used, one wire rope flaw detector 2a is disposed on the first and second wire ropes 21 and 22, and the other wire rope flaw detector 2b is On the third and fourth wire ropes 23 and 24, the magnetic flux 10a flowing in the closed loop of the one wire rope flaw detector 2a is located at the same position in the longitudinal direction as the one of the wire rope flaw detectors 2a and the direction of the magnetic flux 10b flowing in the closed loop As shown in FIG. 6, the first magnet 33 and the second magnet 34 are arranged in different directions from the first magnet 31 and the second magnet 32 of the one wire rope flaw detector 2a. Thus, the first magnet 33 of the other wire rope flaw detector 2b is on the drawing, with the S pole on the left, the N pole on the right, and the second magnet 34 on the drawing, with the N pole on the left and the S pole on the right. Arrange .

  Each wire rope flaw detector 2a, 2b arranged as described above is moved in the longitudinal direction on the first, second, third, and fourth wire ropes 21, 22, 23, 24 to perform flaw detection. According to the detection method of the wire rope flaw detector of Embodiment 3 performed in this way, four even number of wire ropes can be inspected simultaneously. In addition, since each wire rope can be magnetized with a substantially uniform magnetic flux density, the gain of the magnetic sensor provided in each wire rope becomes uniform, so that gain adjustment is facilitated. Further, since the leakage magnetic fluxes generated from the adjacent closed loops are repelled in each other, magnetization cancellation does not occur, stable magnetization is obtained, and the flaw detection quality of the four wire ropes is improved.

  In the third embodiment, an example is shown in which two wire rope flaw detectors are used. However, the present invention is not limited to this, and damaged portions of the first, second, third, and fourth wire ropes are detected. In order to achieve this, the wire rope flaw detector shown in FIG. 6 can be moved integrally and provided with a transport unit made of a non-magnetic material. Even if a wire rope flaw detector that performs flaw detection by moving the longitudinal direction on the fourth wire rope is configured, the same effect as in the third embodiment can be obtained.

Embodiment 4 FIG.
FIG. 7 is a view for explaining a detection method using a wire rope flaw detector according to Embodiment 4 of the present invention. In the figure, the same parts as those in the above embodiments are denoted by the same reference numerals, and description thereof is omitted. In each of the above-described embodiments, the case where two or four even-numbered wire ropes are flaw-detected has been described. In the fourth embodiment, a case where flaw detection is performed on three wire ropes will be described. Two wire rope flaw detectors shown in the first embodiment are used, one wire rope flaw detector 2a is disposed on the first and second wire ropes 21 and 22, and the other wire rope flaw detector 2c is On the 2nd and 3rd wire ropes 22 and 23, it arrange | positions in a different position in the longitudinal direction from one wire rope flaw detector 2a. In addition, the magnetic sensor 5 of the other wire rope flaw detector 2 c is configured only by the second sensor portion 55 formed at a position adjacent to the second passage portion 14. This is because the flaw detection of the second wire rope 22 can be performed by the second magnetic sensor 52 of the one wire rope flaw detector 2a, so that the second wire rope 22 passes through the other wire rope flaw detector 2c. This is because it is not necessary to dispose the sensor portion at a position adjacent to the first passage portion 13. In this way, the cost can be reduced by arranging only one sensor unit.

  The wire rope flaw detectors 2a and 2c arranged as described above are moved in the longitudinal direction while maintaining the positional relationship of different positions in the longitudinal direction on the first, second, and third wire ropes 21, 22, and 23. Let the flaw detection. According to the detection method of the wire rope flaw detector of Embodiment 4 performed in this way, three odd-numbered wire ropes can be inspected simultaneously. According to the detection method of the wire rope flaw detector of Embodiment 3 performed in this way, when simultaneously inspecting an odd number of three or more wire ropes, magnetization overlap occurs in at least one rope. However, by arranging the magnets in a staggered manner for the overlapping ropes and disposing the magnetizing sections away from each other in the longitudinal direction, each wire rope can be magnetized with a substantially uniform magnetic flux density. If the magnetic flux density of each wire rope is uniform, the gain of the magnetic sensor provided in each rope is also uniform, so that gain adjustment is facilitated. In addition, since the magnetization directions in the ropes belonging to the two closed loops repel each other, the rope magnetizations do not cancel each other and stable magnetization can be obtained, and the flaw detection of the three wire rope inspections Improve the quality.

  In the fourth embodiment, an example is shown in which two wire rope flaw detectors are used. However, the present invention is not limited to this, and damaged portions of the first, second, third, and fourth wire ropes are detected. In order to do so, the wire rope flaw detectors shown in FIG. 7 can be moved integrally and provided with a transport unit made of a non-magnetic material. Even if a wire rope flaw detector that performs flaw detection by moving the longitudinal direction on the wire rope is configured, the same effect as in the fourth embodiment can be obtained.

2, 2a, 2b, 2c wire rope flaw detector, 5 magnetic sensor, 8 base plate,
10, 10a, 10b Magnetic flux, 11, 15 Damaged part, 12 Leakage magnetic flux,
13 1st passage part, 14 2nd passage part, 21 1st wire rope,
22 second wire rope, 23 third wire rope, 24 fourth wire rope,
31, 33 1st magnet, 32, 34 2nd magnet, 41, 45 1st interpolation part,
42, 46 Second interpolation unit, 43, 47 Third interpolation unit, 44, 48 Fourth interpolation unit,
51,53 1st sensor part, 52,54 2nd sensor part.

Claims (10)

In a wire rope flaw detector for detecting a damaged portion of any one of the wire ropes among a plurality of wire ropes,
First and second passage portions serving as passages of the wire rope with a spacing in a direction perpendicular to the longitudinal direction of the wire rope;
A first magnet disposed between the first passage portion and the second passage portion;
A second magnetic pole disposed between the first passage portion and the second passage portion and spaced apart in the longitudinal direction of the first magnet and the wire rope and having a magnetic pole direction different from the magnetic pole direction of the first magnet; A magnet,
A magnetic sensor disposed between the first magnet and the second magnet,
When the different wire ropes are respectively disposed on the first and second passage portions, a closed loop is formed by the wire ropes and the first and second magnets,
A wire rope flaw detector, wherein the magnetic sensor detects a damaged portion of the wire rope by detecting a magnetic flux other than the magnetic flux flowing through the closed loop. A first interpolation unit formed in close contact with the first pole side of the first magnet and reaching the first passage unit;
A second interpolation unit formed in close contact with the second pole side of the first magnet and reaching the second passage unit;
A third interpolation part formed in close contact with the second pole side of the second magnet and reaching the first passage part;
A fourth interpolation unit formed in close contact with the first pole side of the second magnet and reaching the second passage unit;
The closed loop is formed by the wire ropes, the first and second magnets, and the first to fourth interpolation units when different wire ropes are respectively disposed on the first and second passage portions. The wire rope flaw detector according to claim 1. The magnetic sensor includes a first sensor portion formed at a position adjacent to the first passage portion and a second sensor portion formed at a position adjacent to the second passage portion. The wire rope flaw detector according to claim 1 or 2, characterized by the above. At least one of the first interpolation unit, the second interpolation unit, the third interpolation unit, and the fourth interpolation unit is formed so that the insertion side of the wire rope is opened and the side surface of the wire rope is surrounded. The wire rope flaw detector according to any one of claims 1 to 3, wherein the wire rope flaw detector is provided. The wire sensor flaw detection according to any one of claims 1 to 4, wherein the magnetic sensor is formed so that an insertion side of the wire rope is opened and a side surface of the wire rope is surrounded. vessel. Said first and second passage portions, said first and second magnets, and the magnetic sensor, can be moved in integral with the longitudinal direction of the wire rope, and with a transport unit consisting in a non-magnetic material The wire rope flaw detector according to any one of claims 1 to 5, wherein the wire rope flaw detector is provided. In a wire rope flaw detector for detecting a damaged portion of the first, second and third wire ropes,
Two wire rope flaw detectors according to any one of claims 1 to 5, wherein the wire rope flaw detectors are arranged so as to have different positional relationships in the longitudinal direction of the wire rope , and can be moved together, and non- It has a transport unit made of magnetic material,
A wire rope flaw detector characterized in that flaw detection is performed by moving the longitudinal direction on the first, second and third wire ropes by the transport unit. In the wire rope flaw detector for detecting a damaged portion of the first, second, third, and fourth wire ropes,
Two wire rope flaw detectors according to any one of claims 1 to 5, the same positional relationship in the longitudinal direction of the wire rope , and the magnetic flux flowing through the closed loop of the one wire rope flaw detector The first magnet and the second magnet can be arranged and moved integrally so that the direction is different from the direction of the magnetic flux flowing in the closed loop of the other wire rope flaw detector, and the nonmagnetic material can be used. Comprising a transport section
A wire rope flaw detector characterized in that flaw detection is performed by moving the longitudinal direction on the first, second, third and fourth wire ropes by the transport unit. In the method for detecting a damaged portion of the first, second, and third wire ropes,
The two wire rope flaw detectors according to any one of claims 1 to 6, wherein the one wire rope flaw detector is disposed on the first and second wire ropes, and the other wire rope flaw detector is disposed. The wire rope flaw detector is disposed on the second and third wire ropes at a different position in the longitudinal direction from the one wire rope flaw detector,
A detection method using a wire rope flaw detector, wherein flaw detection is performed by moving the wire rope flaw detectors in the longitudinal direction on the first, second, and third wire ropes while maintaining the positional relationship. . In the method for detecting a damaged portion of the first, second, third, and fourth wire ropes,
7. Two wire rope flaw detectors according to any one of claims 1 to 6, wherein the one wire rope flaw detector is disposed on the first and second wire ropes, and the other wire rope flaw detector is disposed. The rope flaw detector is on the third and fourth wire ropes at the same position in the longitudinal direction as the one wire rope flaw detector, and the direction of the magnetic flux flowing in the closed loop is the magnetic flux flowing in the closed loop of the one wire rope flaw detector. Arranging the first magnet and the second magnet so that the direction is different from the direction;
A detection method using a wire rope flaw detector, wherein flaw detection is performed by moving each wire rope flaw detector in the longitudinal direction on the first, second, third, and fourth wire ropes.

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