KR102267712B1 - Apparatus for Inspecting Defect of Wire Rope - Google Patents

Abstract

The present invention relates to a wire rope defect inspection apparatus capable of inspecting a defect of a wire rope by using a leakage flux inspection method using a hall sensor. According to the present invention, the wire rope defect inspection apparatus includes: a moving body moving while surrounding a wire rope; and a driving body moving the moving body in a longitudinal direction of the wire rope. The moving body includes: a plurality of heads arranged in a circumferential direction from the outside of the wire rope; a yoke inserted into each of the heads; magnets positioned on both sides of the yoke to be coupled with the heads; a hall sensor positioned between the magnets to maintain a predetermined distance from the wire rope; and a fixing plate integrally fixing the plurality of heads on both sides of the plurality of heads. According to the present invention, as the apparatus is movably installed on a wire rope and moved, there can be an effect of easily and accurately inspecting a defect of the wire rope.

Description

Wire Rope Defect Inspection Apparatus {Apparatus for Inspecting Defect of Wire Rope}

The present invention relates to a wire rope defect inspection apparatus, and more particularly, to a wire rope defect inspection apparatus capable of inspecting a wire rope defect by using a leakage magnetic flux flaw detection method using a Hall sensor.

In general, the wire rope installed in various equipment such as ladder trucks, cranes, elevators, etc. is subjected to large pressure or there is a risk of being locally worn or damaged due to frequent contact with the sheave and may be cut. can lead to major accidents, so periodic inspections are absolutely necessary.

Most wire rope inspection is a method of inspecting wire breakage, severe corrosion and wear through visual inspection and instrument (vernier caliper). It takes a lot of time and money and is highly likely to be judged as human error by individual judgment. To supplement this, recently, a non-destructive inspection device is used to inspect the state of the wire.

Non-destructive testing methods include ultrasonic flaw testing, radiographic testing, and magnetic flaw testing. Ultrasonic flaw testing is not appropriate because of the complicated shape of the wire rope, and radiation penetration testing is difficult in terms of time and cost. Since the wire rope, which is the object to be inspected, is a ferromagnetic material, defects are inspected using the magnetic flaw technique, a useful method for defect detection. The principle of this method is to apply a magnetic field to the wire and detect the defective portion by sensing the magnetic flux leaking from the defective portion of the wire or the change in the magnetic field with a Hall sensor (magnetic sensor). A device for detecting a defect or damage of a wire rope in this way is disclosed in Korean Patent No. 10-2032986, Korean Patent Publication No. 2019-0101998, and the like.

Korean Patent Registration No. 10-2032986 (Registration Date: 2019.10.10.)

Korean Patent Publication No. 2019-0101998 (Published date: 2019.09.02.)

An object of the present invention is to provide a wire rope defect inspection apparatus capable of easily and accurately inspecting a wire rope defect using a leak magnetic flux flaw detection method using a Hall sensor.

A wire rope defect inspection apparatus according to the present invention for achieving the above object includes a movable body moving while wrapping the wire rope, and a driving body for moving the movable body along the longitudinal direction of the wire rope, and the movable body is from the outside of the wire rope. A plurality of heads arranged in the circumferential direction, a yoke inserted into the inside of each head, a magnet positioned on both sides of the yoke and coupled to the head, and a hall sensor positioned between the magnets to maintain a predetermined distance from the wire rope; , and a fixing plate for integrally fixing the plurality of heads on both sides of the plurality of heads.

A pair of V-shaped rollers guiding the wire rope are coupled to the fixing plate.

A plurality of boards are overlapped on the head, which is sandwiched between the yoke and the hall sensor to set the distance between the hall sensor and the wire rope.

The substrate includes a Hall sensor fixed substrate on which the Hall sensor is inserted and fixed, and a plurality of spacing adjustment substrates superimposed on both sides of the Hall sensor fixed substrate, and a wiring passage space for wiring is formed in the middle of the interval adjustment substrate.

An open groove for facilitating wiring is formed in the middle of the head in the longitudinal direction.

According to the wire rope defect inspection apparatus according to the present invention, there is an effect that the defect of the wire rope can be easily and accurately inspected by movably installed and moved on the wire rope.

1 is a conceptual block diagram to which a wire rope defect inspection apparatus according to an embodiment of the present invention is applied.
FIG. 2 is a perspective view showing the main part of 1. FIG.
3A-3C are an elevation view, a central horizontal cross-sectional view, and a side view of FIG. 2 ;
FIG. 4 is a perspective view illustrating one of the magnetization heads in FIG. 2 , in which a yoke, a substrate, and a hall sensor are combined.
5A to 5C are elevation, top and side views of FIG. 4 ;
6 is a perspective view illustrating the Hall sensor fixed substrate of FIG. 5A.
7 is a perspective view illustrating the interval adjusting substrate of FIG. 5A .
8A and 8B are explanatory views showing the inspection principle of a wire rope defect inspection apparatus according to an embodiment of the present invention.
9A to 11B are explanatory views for explaining an experimental example in which a voltage change amount is measured with a wire rope when a wire is disconnected using the wire rope defect inspection apparatus according to an embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. At this time, it should be noted that in the accompanying drawings, the same components are denoted by the same reference numerals as possible. In addition, detailed descriptions of well-known functions and configurations that may obscure the gist of the present invention will be omitted. For the same reason, some components are exaggerated, omitted, or schematically illustrated in the accompanying drawings.

1 is a conceptual configuration diagram to which a wire rope defect inspection apparatus according to an embodiment of the present invention is applied, FIG. 2 is a perspective view showing the main part of 1, and FIGS. 3a to 3c are an elevation view of FIG. 2, a central horizontal cross-sectional view (section AA) ), and a side view. As shown, the wire rope defect inspection apparatus includes a movable body 100 that moves while wrapping the wire rope WR, and a driving body 200 that moves the movable body 100 along the longitudinal direction of the wire rope WR. do.

In the embodiment of FIG. 1 , the driving body 200 is installed in the fixed frame FR1 and as the motor rotates the feed screw, the movable body 100 coupled to the feed screw moves. Since this driving structure is only an example and can be driven by various driving means such as hydraulic pressure, pneumatic pressure, belt, etc., detailed description will be omitted, and only the movable body 100, which is the main part of the present invention, will be described in detail below.

The movable body 100 is fixed to the moving frame FR2 and moved, and a control unit and a display unit not shown may be installed in the moving frame FR2, and a head 110, a yoke 120, and a magnet ( 130 , a Hall sensor 140 , a fixing part 150 , a guide part 160 , and a substrate part 170 .

The head 110 is arranged along the circumferential direction from the outside of the wire rope (WR: see Fig. 1), as shown in Figs. 4 and 5a to 5c, a plurality (eight in this embodiment) is mutually installed in close proximity. The head 110 is made of a non-magnetic material. The head 110 is in the form of an isosceles pentagonal column in which the yoke 120, the magnet 130, and the substrate unit 170 are inserted and installed on one side, and the space in which the yoke 120 and the substrate unit 170 are inserted. And a hole into which the magnet 130 is inserted is formed.

In this embodiment, the eight heads 110 are arranged along the circumferential direction in contact with the adjacent first contact surface 111 and the second contact surface 112 . On the first contact surface 111 side, the yoke 120 and the substrate part 170 are installed to be exposed. An open groove 113 is formed in the middle of the head 110 in the longitudinal direction to easily wire the wires coming out of the hall sensor 140 . The header 110 is open where the hall sensor 140 is installed on the side facing the wire rope. In addition, a hole 114 into which a fastening member (rod) of the fixing part 150 to be described later is inserted is formed in the header 110 along its longitudinal direction.

The yoke 120 is in the form of a rectangular plate fitted to the head 110, and is made of a magnetic material.

The magnet 130 is positioned on both sides of the yoke 120 and has a cylindrical shape that is fitted and coupled to the head 110 .

The hall sensor 140 is positioned between the magnets 130 on both sides and maintains a predetermined distance from the wire rope and detects leakage magnetic flux, and its legs are fitted and fixed to the substrate of the substrate unit 170 to be described later.

The fixing part 150 is a part including fixing plates 151 and 152 for fixing the plurality of heads 110 as one body at both sides of the plurality of heads 110 . In the fixing unit 150, the upper fixing plate 151 and the fixing plate 152 are fitted and detachably coupled by a clasp, so that they are easily coupled from both sides (upper and lower) of the wire rope. The fixing plates 151 and 152 on both sides are fastened to the head 110 by fastening members (bolts, nuts and washers) 153 .

The guide unit 160 is coupled to the fixing plates 151 and 152 to guide the wire rope, and includes a pair of V-shaped rollers 161 and a lug member 162 for supporting the V-shaped roller 161 . do. The lug member 162 is in close contact with the fixing plates 151 and 152 and the lugs 162b protrude from both sides of the lug base portion 162a fixed by the fastening member to support the V-shaped roller 161 . A pair of V-shaped rollers 161 are installed on the shaft member 163 fitted to the lug 162b, and form a rectangular passage 164 for guiding the wire rope as shown in FIG. 3c.

The substrate unit 170 is sandwiched between the yoke 120 and the Hall sensor 140 in the head 110 to set a gap between the Hall sensor 140 and the wire rope, so that a plurality of substrates are overlapped. The substrate includes a Hall sensor fixed substrate 171 having a plurality of holes 171a (refer to FIG. 6 ) in which the legs of the Hall sensor 140 are fitted and fixed, and a plurality of overlapping holes on one or both sides of the Hall sensor fixed substrate 171 . It includes a spacing adjusting substrate 172, and a wiring passage space 172a (refer to FIG. 7) for wiring is formed in the middle of the spacing adjusting substrate 172.

When adjusting the distance between the hall sensor 140 and the wire rope (WR: see FIG. 1 ), it is adjusted by moving the gap adjusting substrate 172 . That is, when the gap is increased, the gap adjusting substrate 172 on the upper side of the Hall sensor fixed substrate 171 is moved to the lower side so that the hall sensor 140 is moved upward, and when the gap is made small, the hall sensor By moving the gap adjusting substrate 172 on the lower side of the fixed substrate 171 upward, the Hall sensor 140 is moved downward.

8A and 8B are explanatory views showing the inspection principle of a wire rope defect inspection apparatus according to an embodiment of the present invention. Figure 8a is a view showing the magnetic field of the normal wire rope (WR), Figure 8b is a view showing the magnetic field leakage magnetic flux is generated when there is a damaged portion in the wire rope.

As shown in Fig. 8a, when the ferromagnetic wire rope (WR) is sufficiently magnetized through the magnet 130, it has magnet-like properties. At this time, the wire rope (WR) and the U-shaped magnet 130 and the yoke (120) forms a magnetic closed circuit. As shown in FIG. 8b , when a local wire breakage (metal loss) occurs in the wire rope WR, the cross-sectional area of the magnetic field passing through the defective portion is reduced. For this reason, all the magnetic flux due to the externally applied magnetic field does not pass through the wire rope WR, but leaks to the outside of the target object. The magnetic flux passing to the outside is called leakage magnetic flux, and this leakage magnetic flux is detected as an output voltage of the Hall sensor 140 .

9A to 11B are explanatory views for explaining an experimental example in which the voltage change amount is measured with a wire rope when a wire is disconnected using the wire rope defect inspection apparatus according to an embodiment of the present invention, 8 (ch1 to ch8 ) is an example showing the amount of voltage change in each channel with the head 110 installed along the circumferential direction.

The Hall sensor 140 used in the experiment is WSH-135, the distance between the Hall sensor 140 and the wire rope WR is 2 mm, the magnet 130 is 5 mm in diameter x 10 mm in length, and the yoke 120 is horizontal. 40mm x 15mm x 7mm thick flat iron, the distance between the magnets on both sides of the longitudinal direction of the yoke was 30mm, and the distance between the magnet and the wire rope was 4mm.

9A shows a case where four wire breaks occur in the channel 2 (ch2) direction of the wire rope WR, and FIG. 9B shows the voltage along with the channel 1 (ch1) and the channel 3 (ch3) adjacent to the channel 2 (ch2). This is a graph showing the amount of change. The graph is shown by measuring 30 times and averaging. The actual voltage change is expressed by multiplying the number on the vertical axis by 4.88mV (the minimum resolution of the AD converter). Accordingly, the voltage change amount of channel 1 is 536.8 mV, the voltage change amount of channel 2 is 634.4 mV, and the voltage change amount of channel 3 is 585.6 mV.

FIG. 10A shows a case in which eight wire breaks occur in the channel 1 (ch1) direction of the wire rope WR, and FIG. 10B is a voltage along with channel 8 (ch8) and channel 2 (ch2) adjacent to channel 1 (ch1). This is a graph showing the amount of change. The graph was shown by measuring 30 times and averaging. The actual voltage change is expressed by multiplying the number on the vertical axis by 4.88mV (minimum resolution of the AD converter). Accordingly, the voltage change amount of channel 8 is 341.6 mV, the voltage change amount of channel 1 is 1024.8 mV, and the voltage change amount of channel 2 is 229.36 mV.

11A shows a case where 12 broken wires occur in the channel 5 (ch5) direction of the wire rope WR, and FIG. 11B shows the voltage along with the channel 6 (ch6) and the channel 4 (ch4) adjacent to the channel 5 (ch5). This is a graph showing the amount of change. The graph was shown by measuring 30 times and averaging. The actual voltage change is expressed by multiplying the number on the vertical axis by 4.88mV (minimum resolution of the AD converter). Accordingly, the voltage change amount of channel 6 is 165.82 mV, the voltage change amount of channel 5 is 683.2 mV, and the voltage change amount of channel 4 is calculated as 341.6 mV.

As shown in the experimental results, the voltage change is the highest in the Hall sensor of the channel in the vertical direction in the defective part, and the leaked magnetic flux density affects the Hall sensors on both sides, and the amount of voltage change is the degree of magnetic force of each head. It can be seen that it varies depending on And, in the case of 12 broken wires, the voltage change amount of channel 5 is 683.2 mV (refer to Fig. 11b), and in the case of 4 broken wires, the voltage change amount of channel 2 is 634.4 mV (refer to Fig. 9b), so the voltage change amount is each It can be seen that the influence of the magnetic force of the head is greater.

Based on the experimental results, according to the amount of voltage change, the size of the defect and the number of disconnection of the wire generated in the wire rope can be found out through the control unit (not shown) and the display unit (not shown) of the wire rope defect inspection apparatus of the present invention.

And, the size of the magnet, the arrangement of the poles, the distance between the magnets, and the distance between the magnet and the wire rope have an important influence on the wire rope magnetization performance. The size of the magnet and the distance between the magnet and the wire rope affect the magnetization performance, but the magnet It was confirmed by experiment that the distance between the wire rope and the wire rope had no significant effect.

On the other hand, the embodiments of the present invention disclosed in the present specification and drawings are merely presented as specific examples to easily explain the technical contents of the present invention and help the understanding of the present invention, and are not intended to limit the scope of the present invention. It will be apparent to those of ordinary skill in the art to which the present invention pertains that other modifications based on the technical spirit of the present invention can be implemented in addition to the embodiments disclosed herein.

100: moving body 200: driving body
110: head 120: yoke
130: magnet 140: hall sensor
150: fixing part 151: fixing plate
152: fastening member 160: guide part
161: V-shaped roller 162: lug member
170: substrate 171: Hall sensor fixed substrate
172: gap adjustment substrate
WR: wire rope

Claims (4)

A moving body that moves while wrapping the wire rope, and a driving body that moves the moving body along the longitudinal direction of the wire rope,
the moving body
A plurality of heads arranged along the circumferential direction from the outside of the wire rope;
a yoke inserted into the inside of each head;
Magnets positioned on both sides of the yoke and coupled to the head;
a hall sensor positioned between the magnets and maintaining a predetermined distance from the wire rope;
a fixing plate for integrally fixing the plurality of heads on both sides of the plurality of heads;
A fixing part including the fixing plate, wherein the upper fixing plate and the lower fixing plate are fitted and detachably coupled to both sides of the wire rope by a clasp, and the upper fixing plate and the fixing plate are fastened to the head by a fastening member;
A portion coupled to the fixing plate to guide the wire rope, and a guide part including a pair of V-shaped rollers and a lug member for supporting the V-shaped roller,
The head is made of a non-magnetic material, and has an isosceles pentagonal column shape in which the yoke and the magnet are inserted and installed on one side, and a space into which the yoke is inserted and a hole into which the magnet is inserted,
A plurality of the heads are arranged such that the first contact surface and the second contact surface are in contact with each other, the yoke is exposed on the first contact surface side, and the wire coming out of the Hall sensor is easily wired in the middle of the head in the longitudinal direction. An open groove is formed, the part where the hall sensor is installed on the side facing the wire rope in the head is open, and a hole into which the fastening member of the fixing part is inserted is formed along the longitudinal direction of the head,
The yoke is in the form of a rectangular plate fitted to the head, and is formed of a magnetic material,
The lug member supports the V-shaped roller by protruding from both sides of the lug base part fixed by the fastening member in close contact with the fixing plate,
A pair of the V-shaped roller is installed on the shaft member fitted to the lug, Wire rope defect inspection apparatus, characterized in that to form a rectangular passage for guiding the wire rope. delete According to claim 1,
Wire rope defect inspection apparatus, characterized in that the head is sandwiched between the yoke and the hall sensor to set a distance between the hall sensor and the wire rope a plurality of substrates are superimposed. 4. The method of claim 3,
the substrate is
a Hall sensor fixing substrate on which the Hall sensor is fitted and fixed;
A plurality of spacing adjustment substrates superimposed on one side or both sides of the Hall sensor fixed substrate,
A wire rope defect inspection apparatus, characterized in that a wiring passage space for wiring is formed in the middle of the interval adjusting substrate.

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