JP2015166697A - rope flaw detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To overcome problems with a conventional rope flaw detector that a wire rope, if decreasing in diameter by abrasion after long-term use, largely vibrates within a wire rope guide, the relative position of the wire rope to a detection coil varies with the vibration of the wire rope, and the variation in the relative position causes a change in magnetic leakage flux from the wire rope to generate noise similar to a wire rope damaged portion.SOLUTION: A rope vibration suppression tool is attached to an opening portion that is an end portion of a guide section that is an inlet/outlet of a wire rope so that the wire rope may slide along a V-shaped guide.

Description

  The present invention relates to a rope flaw detector provided with a magnetic flaw detector that magnetizes a wire rope with a magnet and detects a magnetic flux leaking from a damaged portion with a magnetic sensor, and in particular, the rope diameter of the wire rope is reduced. It is a jig used for inspection in the case of damage.

As a wire rope flaw inspection device, when there is a magnetized part that magnetizes a predetermined section of the wire rope with a permanent magnet or an electromagnet, and when there is a damaged part of the wire rope in the predetermined section, magnetic flux leaking from the vicinity of the damaged part is detected Some have a magnetic flaw detector provided with a magnetic sensor that is a detection unit. This wire rope flaw inspection device is generally called a rope flaw detector.
Conventional rope testers often use a U-shaped guide cover on the contact surface of the wire rope in terms of restrictions on attachment locations and ease of attachment.

Japanese Patent Laying-Open No. 2012-30934 (page 7, FIG. 9)

  Wire ropes tend to have a narrower rope diameter where they often pass the hoist, and due to wear, there is a point where the rope diameter becomes thinner than the nominal diameter even with a single wire rope. Come on. In the conventional rope flaw detector, when the wire rope diameter is smaller than the nominal diameter due to wear, there is a space in the wire rope and the U-shaped guide, and when the wire rope is running, Vibrate extra space. Further, the wire rope and the guide surface of the U-shaped guide portion come into contact with each other when the wire rope slides, and when the sliding resistance increases, the guide portion is worn and must be replaced.

  And when the wire rope vibrates excessively in the inspection with the rope flaw detector, the relative position between the wire rope and the magnetic sensor fluctuates, resulting in a change in the leakage flux from the wire rope, and the signal of the damaged portion of the wire rope. Noise similar to that occurs.

  The present invention has been made to solve the above-described problems, and an object thereof is to obtain the same S / N ratio as that of a new wire rope even when the rope diameter is smaller than the nominal diameter.

The rope flaw detector according to the present invention is
In the rope flaw detector which inspects the presence or absence of damage to the wire rope by detecting the magnetic flux generated by magnetizing the wire rope,
A plurality of magnets that are installed at predetermined intervals in the movement direction of the wire rope and magnetize the wire rope by forming a pair of positive and negative magnetic poles;
A yoke for fixing the plurality of magnets at both ends and magnetically connecting them;
A detection coil installed between the plurality of magnets to detect the magnetic flux;
A magnetizing device that fixes the detection coil, has the plurality of magnets and the yoke, and constitutes a magnetic circuit as a whole to magnetize the wire rope;
A guide portion disposed so as to cover the detection coil and the magnetizing device, and guiding the sliding of the wire rope;
A rope vibration suppression jig that is attached to both ends of the guide portion and holds the sliding position where the wire rope slides and suppresses rope vibration,
It is equipped with.

  According to the present invention, the wire rope slides along the V-shaped guide by attaching the rope vibration suppressing jig to the U-shaped guide opening which is the entrance / exit of the wire rope of the rope flaw detector. Therefore, even in a wire rope whose rope diameter is thinner than the nominal diameter, vibration can be suppressed in the same manner as a wire rope having a nominal diameter.

It is sectional drawing which shows the principal part of the rope flaw detector by Embodiment 1 of this invention. It is a perspective view which shows the principal part of the rope flaw detector by Embodiment 1 of this invention. It is the front view and sectional drawing which show the principal part of the rope vibration suppression jig | tool by Embodiment 1 of this invention. It is a side view which shows the principal part of the rope flaw detector by Embodiment 1 of this invention. It is a side view which shows the positional relationship of the rope flaw detector by Embodiment 1 of this invention, and a wire rope. It is sectional drawing which shows the positional relationship of the rope flaw detector by Embodiment 1 of this invention, and the strand pitch of a wire rope. It is a side view which shows the positional relationship of the rope flaw detector by Embodiment 1 of this invention, and the wire rope installed in multiple numbers.

Embodiment 1 FIG.
Embodiment 1 of the present invention will be described below with reference to FIGS. 1 is a cross-sectional view showing a main part of a rope flaw detector equipped with a rope vibration suppression jig according to Embodiment 1 of the present invention. FIG. 2 is a perspective view showing a main part of the rope flaw detector equipped with the rope vibration suppressing jig according to Embodiment 1 of the present invention. 3 is a front view of the rope vibration suppression jig (FIG. 3A) and a cross-sectional view (BB) of the rope vibration suppression jig (FIG. 3B). FIG. 4 is a side view showing the main part of the rope flaw detector provided with the rope vibration suppression jig according to Embodiment 1 of the present invention.

In FIG. 1, a rope flaw detector inspects for the presence or absence of damage by magnetic flux generated by magnetizing a wire rope, and is configured as follows. The support base 2 has a column 3. A magnetizing device 4 is fixed to the support base 2. The magnetizing device 4 has two permanent magnets 5 a and 5 b and a yoke 6. The permanent magnets 5a and 5b are of the same specification, have a U-shaped cross-sectional shape in the direction intersecting the sliding direction of the wire rope 7, and are fixed to the left and right ends of the yoke 6, respectively. Attached.
The left permanent magnet 5a is arranged so that the positive magnetic pole side is located on the upper side in FIG. The right permanent magnet 5b is arranged so that the negative magnetic pole side is located on the upper side in FIG. In the two permanent magnets 5 a and 5 b, the negative magnetic pole side of the permanent magnet 5 a and the positive magnetic pole side of the permanent magnet 5 b are magnetically connected by a yoke 6.
A detecting coil 8 is fixed to the magnetizing device 4, and a magnetic flux passing through the wire rope 7 magnetized by the magnetizing device 4 is detected by the detecting coil 8.

  That is, the permanent magnets 5a and 5b forming a pair of positive and negative magnetic poles in the present invention have a predetermined interval in the left-right direction in FIG. 1, and in this embodiment, an interval at which the detection coil 8 can be installed is provided. The magnetizing device 4 has a U-shaped magnetic circuit as a whole. The magnetizing device 4 is provided so as to protrude from the yoke 6 upward in FIG. In this embodiment, the wire rope 7 moves in the direction of arrow A relative to the rope flaw detector.

  As shown in FIG. 2, the rope vibration suppression jig 1 is attached to openings at both ends of a U-shaped guide portion 10 that is an entrance / exit of the wire rope 7 of the rope flaw detector 9. The rope vibration suppression jig 1 has a V-shaped cross section that intersects the sliding direction of the wire rope and serves as a guide for the wire rope. The contact portion between the rope vibration suppression jig 1 and the wire rope is the guide portion 10. A guide surface (a semi-cylindrical surface portion formed on the upper portion of the guide portion) having a U-shaped bottom of the guide surface 10a (wire rope and guide). The rope vibration suppression jig 1 mainly supports the wire rope. The contact portion of the rope vibration suppression jig 1 with the wire rope is chamfered. When the rope vibration suppression jig 1 is not provided and only the guide portion 10 is present, the wire rope has a disconnection, so that the opening portion of the guide portion 10 collides with the wire protruding due to the disconnection, and the flare portion of the opening portion is It may break.

As shown in FIG. 3 cross-section (BB) (FIG. 3B), by chamfering the surface of the rope vibration suppression jig 1 in contact with the rope by 1 mm, the wire temporarily disconnected from the wire rope protrudes. Even if it exists, if it is protrusion within 1 mm, it can dodge and the damage by the winding from the wire rope breakage of the rope flaw detector 9 can be reduced.
Further, if the chamfering width is increased, the wire protruding from the wire rope can be displaced by that amount, but in the first embodiment, the width in the rope longitudinal direction of the rope vibration suppression jig 1 is small. Therefore, since there is a possibility of impairing the function of suppressing rope vibration, the thickness is set to 1 mm.

  Since the wire rope 7 is attracted to the permanent magnets 5a and 5b in the rope flaw detector 9 and is pressed against the rope vibration suppression jig 1 as shown in FIG. Even when the rope 7 is run, the wire rope 7 moves (slides) along the V-shaped surface of the rope vibration suppression jig 1.

  Next, the state in which the wire rope vibrates in the rope vibration suppression jig 1 of the first embodiment will be described with reference to the drawings.

  FIG. 5 shows the positional relationship between the rope flaw detector 9 and the wire rope 7 when the rope vibration suppression jig 1 is not attached and the wire rope has a diameter smaller than the nominal diameter. The wire rope 7 is attracted to the U-shaped groove of the guide portion 10 by the attractive force of the permanent magnets 5 a and 5 b in the rope flaw detector 9.

  However, when the rope diameter of the wire rope becomes smaller than the nominal diameter, a space 11 is created between the wire rope 7 and the guide surface 10a of the guide portion 10 as shown in FIG. When the wire rope 7 is run in this state, the wire rope 7 vibrates left and right, and the wire rope 7 moves along the U-shaped surface 10a which is a guide surface. A gap is formed with the detection coil 8 away from the bottom of the U-shaped surface that is the guide surface of 10. When the size of the gap varies, the detection coil 8 detects a leakage magnetic flux similar to that of damage to the wire rope, resulting in noise in detection of a damaged portion of the wire rope.

  The rope flaw detector 9 configured as described above is provided with the rope vibration suppression jig 1 with the permanent magnet 5a and the permanent magnet 5b sandwiched from the direction A which is the relative movement direction of the wire rope 7, and the wire rope 7 and the rope. The wire rope 7 is guided while restricting the relative positions of the flaw detector 9, particularly the permanent magnets 5 a and 5 b and the detection coil 8.

  In addition, in the above, when the space | interval of the rope vibration suppression jig | tool 1 differs from the twist pitch of the strand of the wire rope 7, when the wire rope 7 is guided, it is easy to raise | generate the vibration of frequencies other than a strand component.

  FIG. 6 is a diagram showing the arrangement interval of the rope vibration suppressing jig and the interval of the strand twist pitch of the wire rope 7. When the wire rope 7 is guided to the rope vibration suppression jig 1, when the unevenness of the strand passes through the rope vibration suppression jig 1 on both sides, if one is a trough, the other is a trough, and the other is a crest One is also a mountain.

  If it arrange | positions so that it may become the twist pitch of the strand of a wire rope as shown in FIG. 6 (it is set as the pitch for 16 strands in this Embodiment 1), it will occur when the peak of a strand crosses a rope vibration suppression jig. Vibrations are made uniform at the inlet and outlet, and vibrations at frequencies other than the strand component can be suppressed. Therefore, by cutting the frequency of the strand component by signal processing, it is possible to further suppress the noise of the detection signal caused by the vibration of the wire rope 7 and to perform more stable measurement.

  In this Embodiment 1, although it is set as the pitch for 16 strands, if the pitch of the unevenness | corrugation of a strand is the same as the pitch of the rope vibration suppression jig | tool of both sides, it will not restrict to this, Any number may be sufficient.

  Furthermore, by providing the rope vibration suppression jig 1 and supporting the wire rope 7 on both sides of the movement direction of the wire rope that is outside the permanent magnets 5a and 5b provided in the movement direction of the wire rope, the permanent magnet 5a The bending of the wire rope 7 attracted by the magnetic attractive force of 5b can be suppressed, and the variation in the distance between the wire rope 7 and the detection coil 8 can be reduced. Thereby, the vibration of the wire rope 7 at the time of measurement can be suppressed, the detection signal of the detection coil 8 is stabilized, and the detection accuracy is improved.

  Moreover, since the wire rope 7 does not contact the guide plate with a strong force, the sliding resistance of the wire rope 7 can be reduced. Therefore, the work load can be reduced when measuring by moving the rope tester held by the hand while pressing it against the wire rope 7.

According to the configuration of the present invention, the rope vibration suppression jig 1 is provided on both sides of the opening which is the end of the U-shaped guide portion 10 of the rope flaw detector 9 so that the wire rope can be used for a long time and worn. Even when the rope diameter becomes smaller than the nominal diameter, the wire rope 7 slides along the V-shaped guide and the distance between the V-shaped guides becomes the strand pitch in the same manner as the nominal diameter wire rope. By matching, the vibration of the wire rope 7 is suppressed, and the wire rope can be inspected without changing the S / N ratio of the detection signal of the rope tester.
In the present embodiment, the rope vibration suppression jig 1 is positioned higher than the U-shaped bottom of the guide surface 10a (the contact portion between the wire rope and the guide portion), so that the rope vibration suppression jig can Since it supports, abrasion or a deformation | transformation of the guide part 10 can be suppressed and the lifetime of the guide part 10 can be extended.

  In addition, the method of covering the entire circumference of the wire rope with a rope flaw detector to suppress the vibration of the wire rope may be used for cranes with only one rope. The distance between is narrow. Therefore, it is difficult to cover the entire circumference of the wire rope with a rope flaw detector.

  FIG. 7 shows the positional relationship between the rope flaw detector and the adjacent wire rope when the rope flaw detector is attached to the elevator. In Embodiment 1, since the wire rope is only along the rope vibration suppression jig 1, it is not necessary to cover the entire circumference of the wire rope, and as shown in FIG. 7, in the rope attached to the elevator, The wire rope can be inspected even in a narrow place where the rope interval is the minimum pitch.

Embodiment 2. FIG.
In Embodiment 1, the rope vibration suppression jig 1 is provided to suppress the vibration of the wire rope, but the U-shaped groove of the guide portion 10 may be a V-shaped groove. In this case, even if the rope vibration suppression jig 1 is not provided, the same effect as that of the first embodiment can be obtained.

Embodiment 3 FIG.
When the guide part 10 is in direct contact with the wire rope 7, the guide part 10 is worn or deformed by sliding friction with the wire rope 7. In that case, the guide portion 10 is replaced. However, when the guide portion 10 is bonded to the support using an adhesive, it cannot be replaced immediately. Therefore, the measure to make the rope vibration suppression jig 1 higher than the U-shaped bottom of the guide surface 10a (the contact portion between the wire rope and the guide portion) is that the rope vibration suppression jig supports the wire rope. The wear or deformation of the guide portion 10 can be suppressed. Therefore, the measures described here are more important in order to extend the life until the guide unit 10 is replaced.

In the above embodiment, the permanent magnet has been described as an example. However, the present invention is not limited to this, and the same effect can be obtained even when a magnet such as an electromagnet is used. Moreover, although the case where the number of permanent magnets was two was demonstrated to the example, it is not restricted to this, Even if it is two or more, there exists the same effect.
It should be noted that the present invention can be freely combined with each other within the scope of the invention, and each embodiment can be appropriately modified or omitted.

  DESCRIPTION OF SYMBOLS 1 Rope vibration suppression jig | tool, 2 support stand, 3 support | pillar, 4 magnetizer, 5, 5a, 5b permanent magnet, 6 yoke, 7 wire rope, 8 detection coil, 9 rope flaw detector, 10 guide part, 10a guide surface, 11 Space.

Claims (6)

In the rope flaw detector which inspects the presence or absence of damage to the wire rope by detecting the magnetic flux generated by magnetizing the wire rope,
A plurality of magnets that are installed at predetermined intervals in the movement direction of the wire rope and magnetize the wire rope by forming a pair of positive and negative magnetic poles;
A yoke for fixing the plurality of magnets at both ends and magnetically connecting them;
A detection coil installed between the plurality of magnets to detect the magnetic flux;
A magnetizing device that fixes the detection coil, has the plurality of magnets and the yoke, and constitutes a magnetic circuit as a whole to magnetize the wire rope;
A guide portion disposed so as to cover the detection coil and the magnetizing device, and guiding the sliding of the wire rope;
A rope vibration suppression jig that is attached to both ends of the guide portion and holds the sliding position where the wire rope slides and suppresses rope vibration,
A rope flaw detector characterized by comprising:   2. The rope flaw detector according to claim 1, wherein the guide portion has a V-shaped cross-sectional shape of a guide surface on which the wire rope slides.   3. The rope flaw detection according to claim 1, wherein the rope vibration suppression jig holds a sliding position where the wire rope slides at a position higher than a bottom surface of a guide surface of the guide portion. apparatus.   The rope flaw detector according to any one of claims 1 to 3, wherein the rope vibration suppression jig has a V-shaped cross section of a sliding portion on which the wire rope slides.   The rope flaw detector according to any one of claims 1 to 4, wherein the rope vibration suppression jig is chamfered at an end portion of a surface in contact with the wire rope.   The rope flaw detector according to any one of claims 1 to 5, wherein a pitch between two guides constituting the rope vibration suppressing jig is matched with a strand pitch.

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