JPS59650A - Electromagnetic flaw detector for wire rope - Google Patents

Abstract

PURPOSE:To perform magnetic flaw detection for a wire rope with high precision, by providing plural detecting iron cores, connecting the detection coils reversely in parallel, and canceling synchronizing noises. CONSTITUTION:Plural, e.g. two detecting iron cores 11A and 11B are provided between the opposite-polarity magnetic poles 6A and 6B of an electromagnetic flaw detector 5 facing the wire rope 2 and a leakage magnetic field from the rope 2 is detected by the coils 11A and 11B wound around the iron cores 11A and 11B respectively. Those coils 11A and 11B are connected reversely in parallel to cancel synchronizing noises by differential effect, performing the magnetic flaw detectin of the wire rop with high precision.

Description

DETAILED DESCRIPTION OF THE INVENTION (Subject of the Invention) The present invention relates to an electromagnetic flaw detection device for wire ropes, and more particularly to an electromagnetic flaw detection device for wire ropes suitable for continuously detecting damage to elevator wire ropes, etc. It is something.

(Prior art) Generally, wire ropes used in cable cars and elevators tend to lose their residual strength due to the wires that make up the rope breaking or becoming locally worn during long-term use. Because of this, the ropes are inspected regularly and replaced before an accident occurs. Most of these rope inspections have been done visually, but recently some methods have begun to use magnetism to inspect for damage.

However, this magnetic damage detection method has problems such as low detection sensitivity and large interference noise, making it difficult to obtain sufficient detection accuracy.

(Object of the Invention) The present invention has been developed in view of the above points, and its object is to provide a wire rope electromagnetic flaw detection device with high detection accuracy.

(Summary of the Invention) In order to achieve the above-mentioned objective sound, the present invention provides an even number of detection iron cores that are positioned between first and second magnetic poles facing the wire rope running in the longitudinal direction. These magnetic poles and each detection core are placed facing each other on the rope, and are magnetically connected by a common yoke, and each detection core is fully wound with each detection coil, and each detection coil is connected in antiparallel. As a connection, the vibration noise of the rope is canceled out, and only the damage signal is detected.

(Embodiment) An embodiment of the present invention will be described below with reference to FIGS. 1 to 3. The embodiment shown here is for detecting damage to the wire rope of an elevator.Elevators 0 and 1 are suspended by a wire rope 2, and the other end of the wire rope 2 is connected to a driving steel wheel 4A and a driven steel wheel. A counterweight 3 is connected by being wrapped around the car 4B. In order to detect such damage to the wire rope 2, an electromagnetic flaw detector 5 is installed opposite the wire rope 2.

This electromagnetic flaw detection device 5 has magnetic poles 6A and 6Bt placed opposite the wire rope 2, and two detection cores 7A and 7Bk placed opposite the wire rope 2 at an intermediate position between the two magnetic poles 6A and 6B. ing. the magnetic pole 6A;
61J have different polarities, and both magnetic poles are constituted by magnetic pole cores 8A and 8B having a yoke 9 that is more or less common, and excitation coils IOA and IOB wound around the yoke 9.

On the other hand, 92 detection cores 7A are installed in the middle position.

713 is integrally connected to the yoke 9 on the side opposite to the wire rope.
It is connected to the. Each iron core 7A, 7B is wound with a friend detection coil 11A, IIIJ, and each coil is connected in antiparallel and connected to a display device such as a recording needle or an alarm via a signal amplifier (not shown). There is. Further, each of the excitation coils IOA and IOB is connected to a power source via a power switch (not shown).

In addition, each magnetic pole 6A, 6B and each detection core 7A.

The surface of 7B facing the wire rope 2 is formed with a 0-shaped groove 12' (i-shaped) in order to increase the area facing the wire rope 2 and reduce magnetic resistance.

Each excitation coil 1 of the electromagnetic flaw detection device 5 configured in this way
The wire rope 2 is moved in its longitudinal direction by being excited at 0 A and 10 Bt. If the wire rope 2 is damaged, the detection coils IIA and IIB detect the signal, and it is possible to confirm the presence or absence of damage. For convenience of explanation, the excitation coil 10A is arranged so that the magnetic poles are 6At-N magnetic poles and 6BQ8 magnetic poles.

10B'=! When r-excited, the magnetic end passes through the rope 2 from the N magnetic pole 6A to reach the S magnetic pole 6B on the opposite side, and also from the S magnetic pole 6B to the yoke 9 to reach the N magnetic pole 6A.

Detection of damage in such a flow of magnetic powder will be explained with reference to FIG. First, in FIG. 2, when the intact rope 2 is moving in the direction of the arrow F (from left to right on the paper), the magnetic tail φ0 is only flowing through the circuit as described above, and the detection coil 11A .

No equivalent voltage is applied to 11B. Next, as shown in Fig. 4, when the damaged part 2P of the rope 2 moves from the 0 position to the P position, in addition to both magnetic poles of the rope 29 and the magnetic end φG passing through the yoke, the damaged part 2P has an N magnetic pole. The magnetic leakage end φ, N, and S
Due to the magnetic poles - magnetic leakage φ, ll occurs. This leakage magnetic tail passes through the detection core 7A near the P position and returns to the N and S magnetic poles, but at this time a signal voltage is induced in the detection coil IIA.

When the damaged part 2P moves from the P position to the Q position due to the movement of the lobe 2, the leakage magnetic end passes through the detection core 7Bt-, so that a signal voltage is induced in the detection coil IIB. By the way, FIG. 4(a) shows the change in the magnetic tail with respect to the movement of the damaged part 2P, and FIGS. 4(b) and 4(C) show the signal voltages detected by the detection coils IIA and IIB, respectively. And actually the detection coil 11A.

11B are connected in antiparallel, the combined voltage becomes as shown in FIG. 4(d), and a waveform with less noise is obtained. That is, when the lobe 2 passes through the U-shaped groove 12 as shown in FIG. 3, the unevenness of the surface of the lobe 2 due to the twisted peaks causes vibration noise A as shown in the enlarged view of FIG. 4(e).
A' is detected by the rain detection coil. For example, if the detection coil 11A' has a positive waveform, the detection coil IIB will have a negative waveform in the ninth direction of anti-parallel connection, and the waveform of the combined voltage will be the waveform of the above-mentioned No. As shown in Figure 4 (d), the vibration noise A, A'
Since they cancel each other out, a low-noise signal waveform is obtained, and only the damage signal voltages P and P' appear as mutually reversed waveforms at positions corresponding to the detection cores 7A and 7B.

FIG. 5 shows a case where the rope 2 has one damaged part 2P1 and a plurality of damaged parts 2P2, and the results are actually measured using the electromagnetic flaw detection device 5 of the above embodiment and the results are recorded on the recording paper 13. According to the number of damage records P
Since 1 + P 2 is recorded, the position and number of 3jX scratches can be easily known.

By the way, in the above-mentioned embodiment, it is impossible to measure anything other than elevators that have a common rope diameter; however, in such a case, only the U-shaped 1412 portion of each core can be replaced with one that matches the rope diameter. With this configuration, it is possible to measure damage to ropes of various diameters using a single electromagnetic flaw detection device. Also, when measuring multiple ropes at the same time,
It is sufficient to configure the U-shaped grooves according to the number of ropes so that they can be attached to and detached from each core. That is, nine opposing parts that meet the conditions of the measuring rope (number of nine diameters, lobe spacing, etc.) are detachably attached to each core end.

It should be noted that the respective iron cores 7A, 7B, 8A, 8B and the yoke 9 may be formed separately and finally integrated, or they may be formed as E-shaped iron cores from the beginning. good. On the other hand, both magnetic poles 6A and 6B are composed of an iron core and an excitation coil, but they can also be replaced with permanent magnets. other than this,
The above embodiment describes the detection of damage to elevator ropes, but the present invention is not limited to elevator ropes, as any wire rope can be measured.

(Effects of the Invention) As explained above, according to the present invention, N magnetic poles and S magnetic poles are all arranged facing the rope, and a detection iron core is arranged facing the rope at an intermediate position between both magnetic poles. In addition to magnetically connecting the magnetic pole and the back side of the detection core, an even number of detection cores were provided at intervals in the longitudinal direction of the rope, each of which was wrapped with a detection coil, and each detection coil was connected in antiparallel, so that synchronization was achieved. It is possible to electrically cancel out the noise caused by the wire rope and detect only the damage signal voltage, and as a result, it is possible to obtain a wire rope electromagnetic flaw detection device with high detection accuracy.

[Brief Description of the Drawings] Fig. 1 is a schematic vertical sectional side view of an elevator showing the state in which the electromagnetic flaw detection device according to the present invention is used, and Fig. 2 is a schematic side view showing the basic configuration of the electromagnetic flaw detection device according to the present invention. Figure 3 is the second
FIG. 4 is an explanatory diagram showing the state of damage detection by the electromagnetic flaw detection apparatus according to the present invention, and FIG. 5 is an explanatory diagram showing the relationship between the damaged rope and the recorded waveform. 2...Wire rope, 6A, 6B...Magnetic pole, 7A
. 7B...Detection iron core, 9...Yoke, IIA, IIB・
...Ken No. 10 Atsushi 30 Mari 4riU

Claims (1)

[Claims] 1. The first wire rope facing the wire rope running in the longitudinal direction
a second pole opposite to the wire rope at a position away from the first magnetic pole in the longitudinal direction and having a different polarity from the first magnetic pole; A detection core that faces the wire rope at an intermediate position between the magnetic pole and is wound with a detection coil, and a yoke that magnetically connects the first magnetic pole, the second magnetic pole, and each back side of the detection core. In the wire rope electromagnetic flaw detection device comprising: an even number of detection cores wound with the detection coils are provided at intervals in the longitudinal direction, and each of the detection coils are connected in antiparallel. Flaw detection equipment.