JPH11304766A - Flaw detector for steel rope - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a flaw detector for steel rope which has a small size and a light weight and can improve the workability of measuring work. SOLUTION: In a flaw detector 1 for steel rope composed of a flaw detector main body 5 provided with an exciter 3 which excites a steel rope 2 and a leakage flux detector 4 which detects leakage magnetic fluxes, a power source for driving the exciter 3 and detector 4, a control circuit 6 which controls the exciter 3 and detector 4, and a display 7 which displays measuring signals front the control circuit 6, a rare-earth transient element magnet, is used as the exciting means of the exciter 3. Since the rear-earth transient element magnet having an extremely small size, light weight, and strong magnetic force as compared with the conventional exciting means is used as the exciting means of the exciter 3, the size and weight of the flaw detector are reduced as a whole and, when the detector is used, measuring work can be carried out extremely easily.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flaw detector for a steel cable for detecting damage to a steel cable using magnetic force.

[0002]

2. Description of the Related Art Conventionally, magnetic flaw detectors have been used for detecting damage caused by use of steel rope machines such as elevators, lifts, cable cars, cranes and the like.

[0003] As shown in Fig. 4, for example, these conventional steel cord flaw detectors have annular magnetic poles 4a at both ends of an exciting coil 3a wound around an iron core 1a and connected to a power supply 2a of a DC power supply. , 5a is fixed, and a leakage magnetic flux detector 7a having a magnetically sensitive element is displayed. The measurement signal is displayed on a display 9a such as a recorder via a control circuit 8a to display the steel cable 10a. This is to confirm the existence of the damaged part.

[0004]

However, the conventional flaw detector for steel ropes has a large and heavy excitation coil 3.
a. Therefore, when working in a limited space, for example, for detecting damage to a steel cable in an elevator, the workability is extremely inconvenient and poor.

Further, the conventional magnetic poles 4a and 5a and the leakage magnetic flux detector 7 must be arranged so as to surround the steel cable, and the workability is also poor in this respect.

Further, in the conventional flaw detector for steel cable, a flaw detector main body 10a having an exciter 6a and a leakage magnetic flux detector 7a is connected to a control circuit 8a and a power supply 2a by a cord 11a. In addition, these cords 11a require an extremely large number of wires because of the necessity of controlling a plurality of magnetically sensitive elements.

[0007] Therefore, the measurer must use these codes 11
Since the flaw detector main unit 10a to which a is connected must be installed on a steel cable, handling becomes extremely complicated, and workability is not good in this respect as well.

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems of the conventional flaw detector for steel cables, and provides a small, light-weight flaw detector for steel cables which is excellent in workability.

[0009]

In order to solve the above-mentioned problems, the present invention uses a rare-earth transition element magnet as an exciting means in an exciter to reduce the size and weight of the apparatus and to make the handling extremely excellent.

Further, in the above-mentioned means, by using a Hall element as the magnetic sensitive element for detecting the leakage magnetic flux, the detection can be made sure and the measurement operation can be simplified.

Further, by installing the control circuit of the exciter and the leak detector in the flaw detector main body, the handling of connection cords at the time of work is improved.

[0012]

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

FIGS. 1 to 3 show a preferred embodiment of the present invention. A flaw detector 1 for a steel rope is provided with an exciter 3 for exciting the steel rope 2 and a leak caused by damage to the steel rope 2. A flaw detector main body 5 having an insertion portion 51 of a steel cable 2 having a U-shaped end face provided with a leakage magnetic flux detector 4 for detecting magnetic flux, a control circuit 6 for the leakage magnetic flux detector 4, And a display 7 for a measurement wave such as a recorder for displaying a measurement signal.

The exciter 3 has a plurality of permanent magnet laminates 32, 32 arranged at both ends of a yoke 31 arranged longitudinally on the base end side of the flaw detector main body 5.

The permanent magnets constituting the laminates 32, 32 are so-called rare-earth transitions which exhibit an extremely strong magnetic force made of an alloy of a rare-earth element such as samarium, cerium, praseodymium and a transition element such as cobalt. Elemental magnets are used.

Accordingly, the size and weight of the exciter can be extremely small and small as compared with the conventional exciter.

The end faces of the laminates 32, 32 have end faces U.
Magnetic pole portions 33, 33 are provided along the insertion portion 51 of the U-shaped steel cable 2 of the V-shaped flaw detector main body 5.

It should be noted that one of the stacks 32,
The pole and the other are S poles, so that the steel cable 2 can be magnetized uniformly and quickly.

Further, the magnetic flux leakage detector 4 is supported by a base 41 provided between the supporting frames 34, 34 of the permanent magnet laminates 32, 32, and extends along the opening of the flaw detector main body 5. A magnetic-sensitive element 43 composed of a plurality of Hall elements is arranged on a substrate 42 arranged along the insertion portion 51 of the steel cable 2 having an U-shaped end surface.

Then, the substrate 42 of the leakage magnetic flux detector 4
A control circuit 6 incorporated in a substrate 61 arranged in the flaw detector main body 5 is connected.

Further, a power supply device 9 for rectifying an alternating current separate from the flaw detector main body 5 into a direct current and adjusting the voltage to a predetermined voltage is connected via a connection cord 81.

Further, the display 7 separate from the flaw detector main body 5 is connected by a connection cord 82 via an amplifier circuit 91 inserted and stabbed in the power supply device 9.

In the drawings, reference numeral 10 denotes a full-wave rectification unit connected to the power supply device 9 and serves to remove a noise signal by applying a bias voltage to a measurement signal.

In the flaw detector for steel cable constructed as described above, first, the power supply device 9 and the indicator 7 are arranged near the measurer and the U-shaped insertion portion 51 of the flaw detector main body 5 is measured. Is inserted and held.

The portion of the steel cable 2 inserted into the magnetic pole portions 33, 33 is excited by the permanent magnet a.

At this time, in this embodiment, since the rare-earth transition element magnet which exhibits a very strong magnetic force even though it is small is used as the exciting means, the measuring portion of the steel cable 2 is excited beyond the saturation state as it is. .

The main body 5 of the flaw detector can excite and detect magnetic flux by a simple operation of simply inserting the steel cable 2 into the U-shaped insertion portion 51. In addition, the exciting means is small and lightweight. It is very easy to install the flaw detector 1 for steel cable on the steel cable 2.

Next, a DC current of a predetermined voltage is supplied from the power supply device 9 to the control circuit 6, and the leakage magnetic flux detector 4 is operated.

At this time, in the present embodiment, since the control circuit 6 is housed in the flaw detector main body 5, the connection between the flaw detector main body 5 and the measurer is made by the cord 81 connected to the power supply.
However, the handling is extremely simple compared to the case where a considerably large number of connection cords are required as in the prior art.

When measuring the steel cable 2 of, for example, an elevator, the steel cable 2 is moved in the axial direction at a predetermined speed in a state where the steel cable 2 is inserted into the main body 5 of the flaw detector. The resulting change in magnetic flux is detected.

Then, the detected waveform is displayed and recorded on the display 7, and the presence of the damaged portion is detected from the change in the waveform.

[0032]

As described above, the present invention uses a rare-earth transition element magnet which is extremely small, lightweight and has a strong magnetic force as the exciting means of the exciter as compared with the conventional means. Measurement work is very easy.

Further, since the Hall element is used as the detecting means of the leakage magnetic flux detector, the measuring section can be made U-shaped to simplify the measuring operation.

Furthermore, the control circuit for the exciter and the leak detector is housed in the flaw detection apparatus main body, so that the number of connection cords interposed between the flaw detection apparatus main body and the person to be measured is extremely reduced. Good handling at the time.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing a preferred embodiment of the present invention.

FIG. 2 is a side view of the embodiment shown in FIG.

FIG. 3 is a preferred circuit diagram in the embodiment shown in FIG. 1;

FIG. 4 is an explanatory view showing a conventional example.

[Explanation of symbols]

1 flaw detector for steel cable, 2 steel cable, 3 exciter, 4
Leakage magnetic flux detector, 5 flaw detector main body, 6 control circuit, 7 display, 43 magnetic sensitive element.

Claims (3)

[Claims] 1. A flaw detection apparatus main body comprising: an exciter for exciting a steel cable; and a leakage magnetic flux detector for detecting a leakage magnetic flux caused by damage to the steel cable; a drive power supply for the exciter and the leakage magnetic flux detector; In a flaw detector for a steel cable comprising a control circuit of a detector and a leakage magnetic flux detector, and a display of a measurement signal from the control circuit, a steel cable characterized in that a rare earth transition element magnet is used as an exciting means in the exciter. Flaw detector. 2. The flaw detector for a steel cable according to claim 1, wherein a Hall element is used as a magnetic sensitive element for detection of the leakage magnetic flux detector. 3. The flaw detector for a steel cable according to claim 1, wherein a control circuit for the exciter and the leak detector is housed in the flaw detector main body.