JPH07198684A - Wire rope damage detector - Google Patents

Abstract

PURPOSE:To provide a wire rope damage detector which is easy in carrying and excellent in operability. CONSTITUTION:A magnetizer 25 on which permanent magnets are mounted apart by a specified distance from each other at both ends of a strap ferromagnetic plate is formed using a pair of permanent magnets in an exciting means to magnetize a wire rope. Also a probe 10 in which a probe coil 5 to detect leaked flux is incorporated is installed on the magnetizer 25 to form a probe with magnetizer 21. Then the probe with magnetizer 21 is connected to a controller 22 arranged apart from the probe with a long signal cable 23.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wire rope damage detector, and particularly to a portable type suitable for maintenance and inspection of wire ropes such as cranes stretched at high places and elevators installed in a narrow work space. The present invention relates to a wire rope damage detector.

[0002]

2. Description of the Related Art Wire ropes of this type are used not only for static ropes but also for various types of ropes such as gondola lifts at ski resorts, construction cranes and elevators. Since such wire rope is damaged by bending, tensile fatigue, friction, etc., such as wire breakage and local wear, it is necessary to regularly inspect for wire breakage for security reasons.

The damage inspection of the wire rope in use as described above has conventionally been conducted by visual inspection. However, not only it takes a lot of time and labor, but also internal disconnection cannot be detected. The law has been adopted.

There are several types of electromagnetic flaw detection methods, but the magnetic flux leakage method is generally used for detecting local damage. The magnetic flux leakage method is composed of a magnetizer for magnetizing the wire rope, a probe that incorporates a probe coil to detect a damaged portion, a controller that processes a detection signal, etc. As shown in FIG. 3, the electromagnet 1 provided inside the magnetizer strongly magnetizes the wire rope 2 to pass the magnetic flux 3 in the longitudinal direction of the wire rope 2. At this time, if the wire rope 2 is broken or locally worn, a leakage magnetic flux 3a is generated at the damaged portion 4. Wire rope 2
Moves and the probe coil 5 built in the probe and the leakage magnetic flux 3a interlink, a slight voltage is generated in the probe coil 5. This voltage is detected by the electronic circuit of the controller and detected,
Signal processing such as amplification is performed and output as a flaw detection signal.

FIG. 7 shows an example of recording a flaw detection signal detected by the magnetic flux leakage method. The signal waveform of a new rope without disconnection has a noise level with a small absolute value, as shown in FIG. In the signal waveform of the rope including the disconnection, as shown in FIG. 6B, the signal waveform of the voltage greatly protruding corresponding to the disconnection location is detected, and the presence or absence of the disconnection can be visually recognized at a glance.

FIG. 8 shows an example of a conventional portable wire rope damage detector 6 using the magnetic flux leakage method. A controller 8 and a wire rope 2 for processing a detection signal in a box-shaped casing 7 are shown in FIG. A magnet coil 9 for magnetizing the magnet is housed, and a probe coil 5 for detecting the leakage magnetic flux 3a is provided above the housing 7.
It has a structure in which a probe 10 having a built-in is integrally mounted.

That is, the magnetizer 9 is of an electromagnetic type and is composed of an iron core 11, a magnetic core 12, an exciting coil 13 and the like, and has N and S poles 14a and 14b projecting from the outer surface of the housing 7. . Further, the probe 10 has both magnetic poles 14a and 14b.
Magnetically connected to the magnetic poles 14a and 14b and the wire rope 2
The pole parts 15 and 16 that approach and lead to the peripheral wall surface of
A guide portion 1 having a guide wall 17 which is attached to the tip ends of the pole portions 15 and 16 in a bridging shape, and which is provided opposite to the peripheral wall surface of the wire rope 2 to pass the wire rope 2 in a sliding contact manner.
8 and the central guide wall 17 between the pole portions 15 and 16
And a probe coil 5 for detecting the leakage magnetic flux 3a.

More specifically, as shown in the side view of FIG. 9, the guide portion 18 is composed of a pair of split pieces 18a and 18b having semi-arcuate inner walls, and the inner wall surfaces of the two are opposed to each other. The arc-shaped guide wall 17 is formed, and the flange portions at both ends thereof are pivotally fixed to the side surfaces of the pole portions 15 and 16 so as to be openable and closable. Also, the pole parts 15, 16
A hook 19 is provided on the outer wall surface of the lower end of the hook, and the hook 19 is fixed by a catch 20 provided on the housing 7 in a catch clip manner so that both are integrally fixed.

In the portable wire rope damage detector 6 having such a structure, the N poles and S poles 14a and 14b of the magnetizer 9 are led out to the tip ends of the pole portions 15 and 16, and the arc-shaped guide wall 17 is provided. The wire rope 2 passing inside is magnetized,
The leakage magnetic flux 3a is detected by the probe coil 5 arranged on the inner wall of the guide wall 17. In this case, in the damage detector 6, the probe 10 is of a split type, and can be attached to or detached from the wire rope 2 by opening and closing the guide portion 18.
Since the probe coil 5 is arranged in an arc shape surrounding the wire rope 2 to be detected, the leakage magnetic flux 3a can be detected with high sensitivity over the entire wall surface of the wire rope 2.

Then, the flaw detection signal subjected to the signal processing is displayed on a level meter, and the flaw detection waveform is recorded / recorded by a monitor terminal.
It could be saved. Also, the probe is detachable, and a general-purpose detection device can be configured by preparing various probes according to the diameter of the wire rope to be detected, or the size and weight of the housing can be made as small as possible to make it portable. It could also be used as a detection device.

[0011]

However, in the above-mentioned conventional magnetic flux leakage type damage detector, an electromagnet is used as a magnetizer for magnetizing the wire rope, and in order to obtain a predetermined magnetic flux density, It was necessary to use a considerably large iron core, a magnetic core, and an exciting coil, and a large power supply was required for this excitation, as well as a wire cable connecting the power supply and the electromagnet. Therefore, the device is generally large in size, heavy in weight, inconvenient to carry, and poor in operability. For example, in the case of a damage detector for a portable wire rope such as an elevator having a relatively small diameter of 8 to 18 mmφ, the size and weight of the magnetizer are 200 × 200 × 60 m.
m, 5.5 kg, the size and weight of the controller is 170 ×
It was about 250 × 125 mm, about 3.5 kg, and the integrated device was considerably large in size, heavy in weight, inconvenient to carry, and poor in operability.

Therefore, there has been a problem that maintenance and inspection of the wire rope stretched on a high ceiling such as a crane and maintenance of the wire rope stretched especially in a narrow detection space such as an elevator are difficult to perform.

Therefore, the present invention has been made in view of the problem of the operability of the above-mentioned conventional magnetic flux leakage type portable damage detector, in which a large and heavy magnetizer is made as small as possible.
An object of the present invention is to provide a magnetic flux leakage type damage detector which is light in weight, easy to carry and easy to operate.

Therefore, the damage detector of the present invention uses a pair of permanent magnets as an exciting means for magnetizing the wire rope, and these permanent magnets are connected to both ends of the strip-shaped ferromagnetic plate. The magnetizer is arranged at a predetermined distance. Then, a probe with a built-in probe coil for detecting a leakage magnetic flux is mounted on the magnetizer to form a magnetizer-attached probe in which the magnetizer and the probe are integrated, and the magnetizer-attached probe is used as a controller casing. It is arranged so that it can be separated from. Further, it is configured so that it can be used as a separate type or an integrated type device depending on the place of use, such as during maintenance in which a large number is stretched in a high place or a narrow place. Further, the magnetizer is configured by disposing non-magnetic magnet cases for mounting permanent magnets on both ends of a strip-shaped ferromagnetic plate and mounting a plurality of magnet pieces on the magnet case. In addition, the controller has a recess for mounting the probe, and has a compact structure with a depth length. As for the probe, an open type probe with an open tip or an open / close type probe is used to obtain operability, and the length of the probe and the length of the probe coil that are opposed to the wire rope are set to obtain a predetermined sensitivity. Specifically, it is configured as follows. That is, the wire rope damage detector of the present invention is a magnetizer in which a pair of permanent magnets whose magnetic poles are reversed are arranged at a predetermined distance on both ends of a ferromagnetic plate, and poles erected on both sides. Portion, a probe having a guide portion bridged to the upper end side of the pole portion and having a guide wall formed at the tip, a probe coil disposed on the inner surface of the guide wall, and a detection voltage of the probe coil And a controller for signal processing, the lower end side of the pole portion of the probe is mounted on the magnetic pole of the magnetizer to form a magnetizer-provided probe in which the magnetizer and the probe are integrated. It is characterized in that it is arranged so that it can be separated from the controller. In the wire rope damage detector of the present invention, a plurality of permanent magnets are stacked and attached to the magnet case of a strip-shaped ferromagnetic plate having non-magnetic magnet cases arranged at both ends of the magnetizer. It is characterized by that. In addition, the wire rope damage detector of the present invention is characterized in that the probe with magnetizer and the controller are connected by a long signal cable, and the probe and the controller are separately arranged. In the wire rope damage detector of the present invention, the magnetizer probe is characterized in that a handle and a fixture for operation are integrally attached to the magnetizer. Further, the wire rope damage detector of the present invention is characterized in that the magnetizer-equipped probe is integrally mounted on a wall surface of a housing of the controller, and the probe and the controller are integrated. Further, in the wire rope damage detector of the present invention, the controller has a recess formed on the wall surface of the housing to which the probe with magnetizer is attached and fixed, and the dimension length of the integrated damage detector is reduced. It is characterized by that. Further, the wire rope damage detector of the present invention is characterized in that the probe is a probe in which the guide wall has a U-shaped cross section and the tip side is open. In the wire rope damage detector of the present invention, the ratio A between the length A between the magnetic poles of the pair of permanent magnets and the length B of the coil portion of the probe coil is A:
The feature is that B is set to (4 to 10): 1.

[0014]

The magnetizer has a structure in which permanent magnets of opposite polarities are arranged at both ends of a strip-shaped ferromagnetic plate. Since permanent magnets are used as exciting means, the weight of the iron core, magnetic core, exciting coil, etc. Since no objects are used, the magnetizer is extremely small,
It can be made lightweight.

Further, in the magnetizer, since the magnet case is arranged at the magnet mounting position of the strip-shaped ferromagnetic plate, the permanent magnet is accurately positioned and the magnetomotive force is separated into an appropriate magnitude. Since a plurality of permanent magnets are stacked and mounted, workability of magnetizer assembly can be obtained.

Since the probe with magnetizer in which the probe is integrated with the magnetizer which is reduced in size and weight is arranged so as to be separable from the controller, it can be used as a separate type or an integrated type device depending on the place of use. can do.

In this case, a large number of the above-mentioned magnetizer-provided probe and controller connected by a long signal cable and separated from the detector and controller are stretched at high or narrow places. The controller can be maintained and inspected in a safe place away from the site simply by installing a small, lightweight magnetized probe on site. Further, this probe with a magnetizer can be stably installed by a handle or a fixture provided in the magnetizer, and can be easily operated.

Further, the probe with magnetizer is integrally mounted and fixed on the wall surface of the housing of the controller, so that a portable and small wire rope damage detector that is convenient to carry and can be obtained. That is, the strip-shaped ferromagnetic plate of the magnetizer constitutes a good return circuit of the wire rope magnetizing circuit and also has a good shield plate function for the controller mounted and fixed. Therefore, not only is the magnetizer not located in the controller, as in conventional portable wire rope damage detectors,
The magnetic shield effect of the strip-shaped ferromagnetic plate alleviates the magnetic influence of the magnetizer, and the controller can be miniaturized as much as possible. Further, when the controller has a recess for mounting the probe with a magnetizer on the wall surface of the housing, the probe does not protrude from the controller, and the depth dimension of the detector can be reduced. Further, when an open-ended probe with an open tip is used, the tip can be set just by applying it to a wire rope, and operability can be obtained in a place where the detection space is narrow.

The ratio A of the length A between the magnetic poles of a pair of magnets along the wire rope and the coil length B of the probe coil A:
By setting B to (4 to 10): 1, detection with a high S / N ratio can be obtained, and a highly reliable portable device can be obtained.

[0020]

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

FIG. 1 shows a first embodiment of the present invention, in which a probe 21 with a magnetizer and a controller 22 are connected by a long signal cable 23, and a detector and a controller are separated from each other.
A so-called detachable portable wire rope damage detector 24, which, like the conventional portable wire rope damage detector 6, uses a controller 22 for signal processing a detection signal and a magnetizing wire rope 2. It is composed of a magnetizer 25 and a probe 10 having a probe coil 5 for detecting the leakage magnetic flux 4 built therein.

This portable wire rope damage detector 24
2 is basically different from the conventional damage detector 6 in that the magnetizer 25 is configured by using a permanent magnet as a magnetizing means, and the magnetizer 25 is arranged outside the housing 26 of the controller 22. The point that the probe 10 is attached to the magnetizer 25 to configure the magnetizer-provided probe 21 in which the magnetizer and the probe are integrated, and a long signal cable 23 is provided between the magnetizer-attached probe 21 and the controller 22. The connection points are the same, and the other configurations are the same. Therefore, the same components are designated by the same reference numerals, and the description thereof will be omitted.

The housing 26 is of a small box shape that does not house a magnetizer, and has a leakage magnetic flux 4 detected by the probe 10 inside.
Various electronic circuits for detecting, amplifying, and processing the detection signal of are mounted. A control panel (not shown) is provided on the front side, and various power switches for operating the controller 22, detection signal output display, setting terminals, recorder output terminals, meters and switches such as alarm buzzers, Terminals are provided.

Further, a stopper 20 is provided on the side wall of the housing 26, and a probe 21 with a magnetizer is integrally mounted as required.

FIG. 2 is a perspective view showing the outer structure of the magnetizer 25. A pair of permanent magnets 29, 30 are arranged on a strip-shaped ferromagnetic plate 28 so as to be separated by a predetermined distance. Three
N pole and S for magnetizing the wire rope 2 on the upper surface side of 0
The pole magnetic poles 31a and 31b are formed.

That is, the ferromagnetic plate 28 made of a strip-shaped iron plate
Non-magnetic magnet cases 32 and 33 made of aluminum plates on which permanent magnets 29 and 30 are mounted are arranged on both end sides of the magnets, and the magnet cases 32 and 33 have polarities such that the upper surfaces thereof are the N pole and the S pole, respectively. Together, permanent magnets 29, 3
Wear 0.

As the permanent magnets 29 and 30, rare earth permanent magnets capable of obtaining a strong magnetic force, for example, neodymium-based Nd-Fe-B sintered magnets are used, and 1.2T (12000) as a whole.
In order to obtain a magnetic flux density of about Gauss) and to obtain workability of magnetizer assembly, a plurality of permanent magnets, preferably about three, whose magnetomotive forces are separated into appropriate magnitudes are used. Attach in layers.

According to an experiment conducted by the present inventor, when the wire diameter of the wire rope 2 to be inspected is about 20 mm, the S / N ratio of the detection output is saturated even if the magnetic flux density is increased by 1.2 T or more. This is because, when it is configured with one permanent magnet, it is extremely difficult to attach and detach the magnet to and from the ferromagnetic plate 28 due to the large magnetomotive force, and the assemblability of the magnetizer 23 is extremely poor. In the mounting test, as shown in the drawing, the workability was the best when the three permanent magnets 29a to 29c were stacked and mounted.

Further, pole pieces 34 and 35 made of a ferromagnetic iron plate are arranged at the upper ends of the magnet cases 32 and 33, and both the magnetic poles 31a and 31b of the permanent magnets 29 and 30 are led out to the upper surface side and at the same time upward. Attached to the probe 1
Position 0.

Reference numeral 36 denotes a handle for operation, which is attached to the bottom surface of the ferromagnetic plate 28 of the magnetizer 25. A stopper 37 is provided on the upper end of the side surface to magnetize the probe 10 placed above. A configuration in which it is fixed integrally with the container 25 is adopted.

The probe 10 is the conventional damage detector 6 described above.
The probe 10 has the same structure as that of the probe 10 and has an open-close type structure in which the guide portion 18 is composed of a pair of two split pieces 18a and 18b having semi-circular inner walls. Pole portions 15 and 16 for guiding the two magnetic poles 31a and 31b of the magnetic pole 25 close to the peripheral wall surface of the wire rope 2;
A guide portion 18 which is bridged to the tip ends of the pole portions 15 and 16 and has a guide wall 17 for slidingly passing the wire rope 2, and a probe attached to the inner surface of the guide wall 17 for detecting the leakage magnetic flux 3a. It is composed of a coil 5 and the like.

The probe 10 is fixed in a catch clip manner by engaging a hook 19 provided on the outer wall surface of the poles 15 and 16 with a stopper 37 provided on a handle 36 on the bottom of the magnetizer 25. Both are fixed integrally, and the probe 21 with a magnetizer is configured.

Since the magnetizer 25 itself is small and lightweight in the probe 21 with a magnetizer constructed as described above,
The size and weight of the magnetizer probe 21 to which the magnetizer 25 is attached are 160 × 90 × 40 mm, and an extremely lightweight detection unit of 1.5 kg can be configured. Therefore, in a site such as a crane or a wire rope of an elevator that is stretched in a high place or a narrow place, the magnetizer-equipped probe 21 can be easily installed at the detection position of the wire rope and the controller. A long signal cable 23 can be extended and placed in a safe place such as an office away from the site for maintenance and inspection. In addition, the probe with magnetizer 2
By fixing the handle 36 arranged on the magnetizer 25 when the No. 1 is installed, the magnetizer-equipped probe 21 can be stably installed.

FIG. 3 shows another embodiment of the present invention, which is a so-called integral type portable wire rope damage detector in which a probe 41 with a magnetizer is integrally mounted on an outer wall surface of a housing 26 of a controller 22. 40.

That is, the damage detector 40 of the portable wire rope is the damage detector 24 of the above embodiment, except that the operating handle 36 attached to the magnetizer 25 of the probe 21 with magnetizer is removed. The probe 41 with a magnetizer, from which the handle 36 is removed, is integrally fixed by a stopper 27 arranged on the outer wall surface of the housing 26 of the controller 22. In this embodiment, the magnetizer probe 41 is a wire rope 2
An open-type probe 42 having a U-shaped guide wall that is in sliding contact with is attached.

FIG. 4 is a perspective view showing the external structure of the open type probe 42.

Like the open / close type probe 10, the open type probe 42 also includes the pole piece 3 of the magnetizer 25.
4 and 35, which are attached to the magnetic poles 31 and 31b and lead out the magnetic poles 31a and 31b close to the peripheral wall surface of the wire rope 2;
44, and a thin stainless steel plate that is attached to the tip ends of the pole portions 43, 44 in a bridging shape, is installed opposite to the peripheral wall surface of the wire rope 2 and allows the wire rope 2 to pass in a sliding contact manner. And a guide portion 46 having a non-magnetic guide wall 45 formed. The guide wall 45 is formed in a U-shaped cross-section with the tip side open, and the pole portion 43,
The probe coil 5 wound in a differential manner is arranged on the guide wall 45 between 44.

Since the portable wire rope damage detector 40 using such an open probe has an open tip, the probe 42 can be easily applied to the peripheral wall surface of the wire rope 2. Therefore, the inspection of the wire rope stretched around a limited detection space such as an elevator can be performed very easily.

If a recess 47 for mounting the probe 41 is formed on the wall surface of the housing 26 of the controller 22 for mounting the magnetizer probe 41, mounting strength can be obtained and stable mounting can be achieved. , The tip of the probe does not project much from the controller 22, and the depth dimension of the integrated detector can be reduced.
In the open type probe 42, the probe coil 5 cannot cover the entire circumference of the peripheral wall surface of the wire rope 2 unlike the open / close type probe 10, so that there is a region where the detection sensitivity is slightly lowered. , There was no problem in practice.

FIG. 5 shows the probe 10 with the length of the probe coil 5 set in the range of 10 to 20 in the detection sensitivity (S / N ratio) test of the damage detectors 24 and 40 for the portable wire rope of the present invention. , 42 is a sensitivity characteristic curve obtained by changing the length of the probe, and the length A between the magnetic poles along the wire rope 2 along the horizontal axis (that is, the probe length) A and the length B of the probe coil A / B. Ratio, the vertical axis shows the detection sensitivity (S / N ratio)
Is shown.

From the figure, the S / N ratio increases rapidly as the A / B ratio increases up to an A / B ratio of 6.5, and reaches its maximum at an A / B ratio of 6.5, and conversely above that. You can see that it is decreasing. Usually, if the S / N ratio is 2 or more, detection can be performed with sufficient accuracy, and it is necessary to set the A / B ratio to 4 or more. However, if the A / B ratio is set to 10 or more, the size of the probe 24 itself becomes large, and the weight also becomes heavy, resulting in poor handleability. Therefore, it is desirable to set the A / B ratio in the range of 4 to 10.

In the damage detectors 24 and 40 for the portable wire rope of the present invention constructed as described above, the size and weight of the magnetized probes 21 and 41 are 160 × 90 × 4.
0 mm, 1.5 kg Further, the size and weight of the controller 22 are about 160 × 140 × 75 mm, 1.5 kg, and the total weight and volume are respectively larger than those of the conventional portable wire rope damage detector 10. It was reduced to 1/3 or less, and the size and weight were reduced as much as possible. Further, depending on the intended use, during maintenance and inspection of a high place such as a crane, the magnetized probes 21 and 41 can be separated from the controller 22 and a split type structure can be adopted to improve the handling property. In addition, maintenance and inspection, especially in a limited detection space such as an elevator, is not bulky even as an integrated structure, and operability is obtained, and a portable wire rope damage detector with excellent operability is obtained. Was given.

[0043]

As described above in detail, in the damage detector of the present invention, a pair of permanent magnets are used as an exciting means for magnetizing the wire rope, and permanent magnets are attached to both ends of the strip-shaped ferromagnetic plate to magnetize. Since the magnetizer is configured, it is not necessary to use heavy parts such as an iron core, a magnetic core, or an exciting coil, and the magnetizer can be made extremely small and lightweight. Also, a large power supply for excitation and an electric wire cable connecting the power supply and the electromagnet are not necessary, and the controller for storing them can be made small and lightweight. Further, the shielding function of the strip-shaped ferromagnetic plate eliminates the influence on the signal processing unit, and the size of the controller housing can be reduced, and the outer size of the detector in which the probe and the controller are integrated can be further reduced. In addition, the handling and maintenance of the wire rope stretched at a high place such as a crane can be handled, and the detection unit can be appropriately separated in a place where the detection space is limited such as an elevator, which facilitates the operation. Furthermore, by using an open-type probe with an open tip, it is possible to provide a portable wire-rope damage detector with improved operability and excellent handleability.

[Brief description of drawings]

FIG. 1 is a perspective view of a damage detector for a detachable portable wire rope according to a first embodiment of the present invention.

2 is a perspective view of a magnetizer with the components of FIG. 1. FIG.

FIG. 3 is a perspective view of an integrated portable wire rope damage detector according to a second embodiment of the present invention.

FIG. 4 is a perspective view of the open type probe of the components shown in FIG. 3;

FIG. 5 is a sensitivity characteristic curve diagram obtained by the damage detector of the present invention.

FIG. 6 is a principle diagram of detection of a damaged portion of a rope by a magnetic flux leakage method.

FIG. 7 is a diagram showing a recording example of a flaw detection signal detected by a magnetic flux leakage method.

FIG. 8 is a front view of a conventional portable wire rope damage detector.

9 is a side view of the damage detector of FIG. 7. FIG.

[Explanation of symbols]

 5 Probe coil 10, 42 Probe 15, 16, 43, 44 Pole part 17, 45 Guide wall 18, 46 Guide part 22 Controller 23 Signal cable 24, 40 Wire rope damage detector 25 Magnetizer 26 Enclosure 28 Ferromagnetism Plates 29, 30 Permanent magnets 31a, 31b Magnetic poles 32, 33 Magnet case 36 Handle 47 Recess

Claims (7)

[Claims] 1. A magnetizer in which a pair of permanent magnets whose magnetic poles are inverted is arranged at a predetermined distance from each other on both ends of a ferromagnetic plate, pole parts erected on both sides, and an upper end side of the pole part. A guide portion having a guide wall formed at the tip end, which is arranged in a bridge with
It consists of a probe having a probe coil arranged on the inner surface of the guide wall, and a controller for processing the detected voltage of the probe coil, and the lower end of the pole of the probe is mounted on the magnetic pole of the magnetizer to magnetize it. A damage detector for a wire rope, characterized in that a probe with a magnetizer is integrated with a probe and a probe, and the probe with a magnetizer is arranged so as to be separable from the controller. 2. A wire according to claim 1, wherein a plurality of permanent magnets are laminated and mounted on the magnet case of a strip-shaped ferromagnetic plate having non-magnetic magnet cases arranged at both ends. Rope damage detector. 3. The wire rope damage according to claim 1, wherein the probe with magnetizer and the controller are connected by a long signal cable, and the probe and the controller are separately arranged. Detector. 4. The damage detector for a wire rope according to claim 3, wherein the magnetizer probe has an operating handle and a fixture integrally attached to the magnetizer. 5. The wire rope damage detector according to claim 1, wherein the probe with magnetizer is integrally mounted on a wall surface of a housing of the controller, and the probe and the controller are integrated. 6. The wire rope damage detector according to claim 5, wherein the controller has a recess formed in the wall surface of the housing to which the probe with magnetizer is mounted and fixed. 7. The ratio A: B of the length A between the magnetic poles of the pair of permanent magnets and the length B of the coil portion of the probe coil is (4 to
10): The damage detector for a wire rope according to claim 1, wherein the damage detector is set to 1.