JP4378033B2 - Wire rope flaw detector - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
In order to ensure the safety of various facilities using a wire rope, the present invention detects the presence or absence of damage such as a broken wire or broken wire rope without removing the wire rope from various facilities. The present invention relates to a rope flaw detector.
[0002]
[Prior art]
In addition to being used as a static rope, a wire rope constructed by combining a plurality of strands is often used as a moving rope in a lift, crane, elevator or the like. In the wire rope, damage such as disconnection or local wear occurs in the strands constituting the strand due to bending, tensile stress, friction, or the like. Therefore, for safety reasons, it is necessary to periodically inspect for damage, but when inspecting damage to the wire rope in use, conventionally, inspection by electromagnetic flaw detection methods and visual inspection by engineers such as engineers Is carried out in combination.
[0003]
FIG. 11 shows a schematic configuration of a damage detector according to the conventional leakage magnetic flux method. In the damage detector, a pair of permanent magnets 2 and 2 for magnetizing the wire rope 1 of the object to be inspected are provided at intervals in the longitudinal direction so as to surround the wire rope 1, and the pair of permanent magnets 2 and 2 are provided. A leakage flux from the wire rope 1 is detected by a detector 41 provided between the two, and the detection signal is processed by the controller 42 to detect the presence or absence of damage to the wire rope 1.
[0004]
The detector 41 as a sensor is constituted by a pair of differential probe coils 41a and 41b formed along the longitudinal direction of the wire rope 1 and so as to divide the circumference of the cross section into a half-divided state. Has been.
[0005]
When the magnetic flux passes in the longitudinal direction of the wire rope 1 by the permanent magnets 2 and 2, a leakage magnetic flux is generated from a broken portion or a locally worn portion. This leakage magnetic flux is connected to the probe coils 41 a and 41 b of the detector 41. A voltage change occurs due to the crossing, and the voltage change is subjected to processing such as detection and amplification by the controller 42 to obtain a flaw detection signal.
[0006]
[Problems to be solved by the invention]
By the way, the conventional damage detector detects the leakage magnetic flux by a pair of actuating probe coils 41a and 41b arranged in a semicircular shape in the longitudinal direction and the circumferential direction of the wire rope 1, and therefore the detector 41 once. The detection range detected in (1) has a large spread especially in the circumferential direction. Therefore, even if there are multiple disconnections or wear parts in the same circumferential direction, the conventional damage detector counts as one disconnection or wear part, so it is not possible to grasp the correct number of damages. was there.
[0007]
As a result, even if the damaged part is mechanically detected by the leakage magnetic flux method, the number of damaged parts is confirmed again by visual inspection, and it is checked whether the number of damaged parts has reached the wire rope replacement standard. I had to judge.
[0008]
The present invention has been made to solve such a conventional problem. The leakage magnetic flux method is used to more accurately detect damages such as disconnection and local wear at a plurality of points, and these damages can be detected by a wire. An object of the present invention is to provide a wire rope flaw detector capable of automatically determining whether or not a rope replacement standard has been reached.
[0009]
It is another object of the present invention to provide a wire rope flaw detector capable of detecting damage for each strand of a wire rope and making an exchange determination based on the damage.
[0010]
Another object of the present invention is to provide a wire rope flaw detector capable of easily calculating and determining the wire rope moving speed in addition to detecting wire rope damage.
[0011]
[Means for Solving the Problems]
  In order to solve the above-described conventional problems, the invention according to claim 1 is characterized in that a magnetizing means for magnetizing a wire rope formed by twisting a plurality of strands in the longitudinal direction, and a circumferential direction of the wire rope.To correspond to each of the plurality of strandsA plurality of arranged magnetic detection means; a damage signal detection means for deriving a damage signal when the magnetic force detected by the magnetic detection means exceeds a predetermined reference value; and connected to the magnetic detection means. A strand pitch signal output means for obtaining a strand pitch signal of the wire rope that moves relatively; and while the strand pitch signal is counted by a predetermined numberBeforeDerived from the damage signal detection meansEach of the plurality of magnetic detection meansNumber of damage signalsThe totalAnd determining means for determining whether or not the number exceeds a predetermined reference number.
[0012]
Thus, a plurality of magnetic detection means are arranged in the circumferential direction of the wire rope, and it is determined whether or not the number of damage signals exceeds the reference number while the strand pitch signal is counted. The number of places can be detected more accurately, and the necessity of wire rope replacement can be automatically determined.
[0013]
  The invention described in claim 2Magnetizing means for magnetizing a wire rope composed of a plurality of strands in the longitudinal direction, and a plurality of magnetic detection means arranged to correspond to each of the plurality of strands in the circumferential direction of the wire rope, A damage signal detection means for deriving a damage signal when the magnetic force detected by the magnetic detection means exceeds a predetermined reference value; and a strand of the wire rope that is connected to the magnetic detection means and moves relatively A strand pitch signal output means for obtaining a pitch signal; and a total number of the damage signals for each strand from a damage signal derived from the damage signal detection means while the strand pitch signal is counted by a predetermined number. Determining means for determining for each strand whether or not the total number exceeds a predetermined reference number. And wherein the door.
  Claim3The invention described in claim 1Or claim 2In the wire rope flaw detector described in
The magnetic detection means is characterized by being formed in a shape shorter than the circumferential width and the longitudinal pitch of one strand of the wire rope.
[0014]
  Therefore,In addition to the presence or absence of damage for each strand, the number of damaged portions for each strand can be detected, and the necessity of replacing the wire rope can be determined more accurately.
[0015]
  Claim4The invention described in claim 1In any one of ~ 3The described wire rope flaw detector includes a rope speed calculating means for calculating the moving speed of the wire rope by counting the strand pitch signal for a predetermined time.
[0016]
Therefore, in addition to determining whether or not the wire rope needs to be replaced, the moving speed of the wire rope can be detected by counting the number of strand pitch signals per unit time without additionally installing special equipment.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of a wire rope flaw detector according to the present invention will be described in detail with reference to FIGS.
[0018]
FIG. 1 is a perspective view showing the overall configuration of an embodiment of a wire rope flaw detector according to the present invention. As shown in FIG. 1, the wire rope flaw detector of the present invention has a magnetizer 2 composed of a pair of magnets 2 a and 2 b connected so as to be spaced apart by a support 2 c around a wire rope 1 that moves. A leakage magnetic flux detector 3 provided between the pair of magnets 2 a and 2 b is arranged so as to surround the wire rope 1. As the wire rope 1 moves, the relative positions of the wire rope 1, the magnetizer 2 and the leakage flux detector 3 change continuously.
[0019]
The processing device 4 that processes the output signal from the leakage magnetic flux detector 3 is constituted by a microcomputer, and the display device 5 that displays the processing result is connected to the processing device 4.
[0020]
In describing an embodiment of the present invention, the diameter of the wire rope 1 as an object to be inspected is 12 mmφ, and the number of strands constituting the wire rope 1 is eight.
[0021]
Now, the cross section of the surface of the leakage flux detector 3 shown in FIG. 1 perpendicular to the length direction of the wire rope 1 is as shown in FIG. That is, a ring body 3a made of a non-magnetic material is provided inside the leakage flux detector 3 so as to surround the wire rope 1 with a gap, and this ring body 3a is a magnetic detection means. A plurality (16 in this embodiment) of magnetic sensors 3b (3b-1 to 3b-16) are arranged at regular intervals as shown.
[0022]
On the other hand, the wire rope 1 has eight strands 1a (1a-1 to 1a-8) each formed by twisting a large number of strands on the outer side of the central core rope 1b (shown in black). The sixteen magnetic sensors 3b are arranged so as to surround the outside of the wire rope 1 in a circumferential shape. The number of magnetic sensors 3b to be arranged is desirably an integral multiple of the number of strands 1a (1a-1 to 1a-8) forming the wire rope 1 in this way.
[0023]
The magnetic sensor 3b outputs an analog signal corresponding to the magnetic force of the leakage magnetic flux of the wire rope 1 incident perpendicularly to the detection surface. As shown in FIG. 3, each magnetic sensor 3b (3b-1 to 3b- 16) are connected to analog / digital converters 3c (3c-1 to 3c-16), respectively, and the output signals converted into digital signals by the analog / digital converter 3c are supplied in parallel to the processing device 4. The Of course, an amplifier can be appropriately provided between the magnetic sensor 3b and the analog / digital converter 3c as necessary. In addition, each analog output can be input to one analog-digital converter via a multiplexer for signal processing. Alternatively, the output of each magnetic sensor 3b (3b-1 to 3b-16) may be swept, converted into a serial signal, converted into a digital signal, and then supplied to the processing device 4.
[0024]
Next, the processing device 4 will be described. The processing device 4 is constituted by a microcomputer, periodically takes a digital signal from the leakage magnetic flux detector 3, processes the signal to detect a strand pitch signal and a damage signal, and determines a predetermined signal based on these signals. Compared with a reference value or the like, it is determined whether or not the wire rope needs to be replaced, and the determination result is output.
[0025]
That is, as shown in FIG. 4, the processing device 4 includes a timer 4a for setting an input cycle of a signal detected by the magnetic sensor 3b of the leakage flux detector 3, and a central processing unit (CPU) 4b. And a read-only memory (ROM) 4c storing a program executed by the central processing unit 4b, an input signal from the leakage magnetic flux detector 3, a calculation result in the central processing unit (CPU) 4b, and the like. A rewritable memory (RAM) 4d to be stored, a digital input circuit (DI) 4e for receiving a digital signal from the magnetic sensor 3b, etc., and a digital for outputting the calculation results and determination results in the central processing unit 4b to the display 5 An output circuit (DO) 4f and a storage medium 4g used for taking out data stored in the rewritable memory 4d to the outside. Between growth units are commonly connected by the bus line 4h. In addition, an input device such as a keyboard is also provided, but the illustration is omitted.
[0026]
Next, the operation of the first embodiment in the wire rope flaw detector of the present invention configured as described above will be described with reference to FIGS.
[0027]
FIG. 5 is a flowchart showing the operation steps of the apparatus in the present embodiment. FIG. 6 shows an analog detection signal obtained from one magnetic sensor 3b by the movement of the wire rope 1, and the detection signal. The timing chart of the signal obtained by introducing and processing by the processing device 4 is shown.
[0028]
That is, FIG. 6A shows a detection signal of magnetic flux density, that is, magnetic force detected by one magnetic sensor 3b (for example, 3b-1) in the leakage flux detector 3, and the detection signal includes It shows that leakage magnetic flux signal components (21a, 21b, 21c) from damages such as wire breakage and local wear are included.
[0029]
FIG. 6B shows a strand pitch signal representing the strand pitch of the wire rope 1 obtained by introducing the detection signal from the magnetic sensor (3 b-1) and processing the processing device 4. Further, FIG. 6C shows a leakage magnetic flux signal component (21a, 21b, 21c) from damage such as wire breakage or local wear, which is included in the detection signal of FIG. Is a damage signal (23a, 23b, 23c) taken out by arithmetic processing.
[0030]
Such a signal is obtained similarly for all the other magnetic sensors 3b (3b-2 to 3b-16).
[0031]
FIG. 7 shows the signals obtained by the processing of the processing device 4 on the basis of the detection outputs from all the magnetic sensors 3b (3b-1 to 3b-16), with the time axis enlarged compared to FIG. In the timing chart, (a) is the strand pitch signal 22, and (b) is the obtained damage signal 23. Further, (c) is a setting signal 25a in which a determination range for performing replacement determination of the wire rope 1 is set for one strand pitch signal 22a among sequentially obtained strand pitch signals, and (d) Is a setting signal 25b in which a determination range is similarly set for the next strand pitch signal 22b. Then, (e) shows whether or not the replacement determination signal 26 outputted by making a determination whether or not the number of damaged parts within the determination range has been counted (counted) in the processing device 4. Represents.
[0032]
Now, when operating the wire rope flaw detector, the diameter and number of strands of the wire rope 1, the signal processing cycle in the processing device 4, the reference number for replacement determination, and the like are set in the processing device 4 in advance. In the present embodiment, the wire rope 1 as the object to be inspected is formed of eight strands and has a diameter of 12 mmφ. Therefore, the diameter of the wire rope 1 is set to 12 and the number of strands is set to 8, for example, The signal processing cycle is 1 ms, the reference value for determining whether or not the wire rope 1 is damaged in the processing device 4 is 0.25 mT, and the reference value of the damage signal for determining the replacement of the wire rope 1 in the processing device 4, that is, the number of reference damage points Assume that (reference number) is set to 17 respectively.
[0033]
When operating the wire rope flaw detector of the present invention under such settings, the processing device 4 first executes a damage detection operation with one cycle of the flowchart shown in FIG. 5 according to a start instruction from the timer 4a. To do. That is, since the processing cycle is set to 1 ms, a start signal is output every 1 ms from the timer 4a of the processing device 4, and each time the signal is received, the processing device 4 captures the output from each magnetic sensor 3b as step 1. .
[0034]
Since the signals from the respective magnetic sensors 3b (3b-1 to 3b-16) are handled in the same manner, the operation will be described here by paying attention to the signals from one magnetic sensor 3b (for example, 3b-1). .
[0035]
Here, as shown in FIG. 6 (a), the analog output of the magnetic sensor (3b-1) indicates that the wire rope 1 in the longitudinal direction of the wire rope 1 is not damaged if the wire rope 1 is not broken, such as broken wires or local wear. If a change in magnetic flux with a minute amplitude due to unevenness due to the strand pitch is obtained and the wire rope 1 is damaged, the cross-sectional area of the wire rope 1 decreases at that portion, so that the leakage magnetic flux increases, and the magnetic sensor 3b In this way, a large output as indicated by reference numerals 21a, 21b, and 21c is generated. This output is compared with a reference value (0.25 mT) set in advance by the processing device 4, and the outputs of reference numerals 21a, 21b, and 21c exceed the reference value (0.25 mT). It is extracted as the damage signal 23 (23a, 23b, 23c) shown, and is sequentially stored in the rewritable memory 4d.
[0036]
Next, the process proceeds to step 2 in FIG. 5, and an operation is performed in which the magnetic flux density, which is the output of the magnetic sensor (3b-1), is 1 when the magnetic flux density is positive, and 0 when the magnetic flux density is negative, as shown in FIG. This is also stored in the rewritable memory 4d as the strand pitch signal 22. Since the strand pitch signal 22 itself is the same for any magnetic sensor 3b, any output can be used in common. Moreover, since the damage signal 23 (23a, 23b, 23c) is obtained individually for each magnetic sensor 3b (3b-1 to 3b-16) that detects the damaged portion, the damage signal 23 of each magnetic sensor 3b is obtained. The extraction process itself is performed in parallel in real time.
[0037]
FIGS. 7A and 7B show the strand pitch signals 22 and the damage signals 23 from all the magnetic sensors 3b (3b-1 to 3b-16) arranged in time series.
[0038]
Therefore, following step 2 in FIG. 5, in the next step 3, the rising edge of the strand pitch signal 22 is detected, the level of the strand pitch signal 22 changes from 0 to 1, and the rising edge is detected (YES). Advances to step 4 to determine the total number of damage signals 23 up to 8 strands before the pitch. That is, in this embodiment, since the wire rope 1 is composed of a combination of eight strands 1a, the length of one strand of each strand for all the strands 1a (1a-1 to 1a-8), That is, the total number of damaged portions included while the eight strand pitch signals 22 are obtained is sequentially counted at the timing of each strand pitch signal.
[0039]
Therefore, as shown in FIG. 7A, when the rising edge of the strand pitch signal 22a is detected, the range from the rising edge to the rising edge of the eight previous strand pitch signals 22a ′ is set as a determination range. The total number of damage signals 23 included in the range of the setting signal 25a shown in c) is calculated.
[0040]
Next, the process proceeds to step 5, and the total number of damage signals 23 within the range of the calculated setting signal 25a is compared with a preset reference number (17) for replacement determination. As shown in FIG. 7B, since the number of damage signals 23 included in the range of the setting signal 25a is 16, this does not reach the reference number (17), so the determination result is NO. Jump to step 7. When the rising edge of the next strand pitch signal 22b is detected, the setting signal 25b having the determination range from the rising edge to the rising edge of the eight previous strand pitch signals 22b ′ is shown in FIG. 7 (d). The total number of damage signals 23 included in the range of the setting signal 25b is calculated to be 17. Therefore, at this time, the determination result in step 5 is YES, the process proceeds to step 6, the replacement determination signal 26b is output, and the determination signal 26b displays on the display 5 that the wire rope 1 needs to be replaced. Then, the process proceeds to step 7.
[0041]
In step 7, since the total number of damage signals 23 counted in step 4 is output, the indicator 5 is displayed with a message indicating that replacement is necessary, and whether or not the replacement standard for the wire rope 1 has been reached. Regardless, the total number of damage signals 23 can be displayed.
[0042]
After outputting the number of damages in step 7, the process proceeds to step 8, and in step 3, the damage determination for each magnetic sensor 3b (3b1 to 3b-16) is performed together with the case where the rise of the strand pitch signal 22 is not detected (NO). Is done.
[0043]
As described above, according to the first embodiment of the wire rope flaw detector of the present invention, the plurality of magnetic sensors 3b (3b-1 to 3b-16) are arranged on the outer side in the circumferential direction of the wire rope 1. In addition, it is possible to detect the presence or absence of damage more precisely with respect to a plurality of strands 1a fitted together on the outer side of the heart rope 1b, and display the number of damages by comparing with a predetermined reference value, thereby enabling automatic diagnosis. Thus, the time required for the visual inspection by the worker can be greatly reduced.
[0044]
Further, in this embodiment, the magnetic sensor 3b is formed in a shape shorter than the circumferential width and the longitudinal pitch of one strand of the wire rope, and the magnetic sensor 3b is formed in each strand 1a (1a-1 to 1a-). Since it was made to respond | correspond to 8), a more exact automatic diagnosis is possible and the reliability of wire rope 1 replacement | exchange determination can be improved.
[0045]
Next, the operation of the second embodiment of the wire rope flaw detector according to the present invention will be described with reference to FIGS. 1 to 4, 8 and 9. FIG. 8 is a flowchart showing operation steps in the second embodiment, and FIG. 9 is a timing chart similar to FIG. In FIG. 9, (a) is the strand pitch signal 22, (b) is the damage signal 23 of all the strands 1a, and (b ') is the damage for one of the strands. Signal 24. (C) is a setting signal 25a for setting a determination range for the strand pitch signal 22a, and (d) is a setting signal 25b for setting a determination range for the strand pitch signal 22b. And (e) represents the exchange determination signal 26.
[0046]
The feature of the second embodiment is that, in the first embodiment, the total number of damages of one pitch for all the strands is compared with the reference value (number) and judged for replacement. Thus, it is possible to perform the replacement determination by calculating the total number of damages for each of the more combined strands. Therefore, in the second embodiment, the reference number of the damage signal for replacement determination for each strand is added as a value set in advance in the processing device 4, and is set to 5 here, for example. That is, if there are five damaged portions in one pitch of a single strand, it is determined that the wire rope needs to be replaced.
[0047]
When operating the wire rope flaw detector according to the present invention under such settings, the processing device 4 executes a damage detection operation with the cycle shown in FIG. 8 as one cycle in response to a start instruction from the timer 4a. . Since the processing cycle is set to 1 ms, a start signal is output every 1 ms from the timer 4a of the processing device 4, and each time this signal is received, the processing device 4 causes each magnetic sensor 3b (3b1 to 3b16) to be step 11. However, since Step 11 to Step 13 are the same as Step 1 to Step 3 described with reference to FIG.
[0048]
In step 13, if both the rising and falling edges of the strand pitch signal 22 are detected (YES), the process proceeds to step 14. In step 14, it is determined whether the detected edge is rising or falling, and the rising edge is determined. If the rising edge is detected, the process jumps to step 20. If the rising edge is detected, the process proceeds to step 15. The total number of damage signals 23 of all the strands 1a up to 8 pitches before the strands (1a-1 to 1a-1). 1a-8) Determine the total number of damage signals 24 for each.
[0049]
In this embodiment, in order to detect a damaged portion corresponding to each strand 1a, it is necessary to sequentially change the detection signal from the magnetic sensor 3b, and the strand pitch signal 22 is used as a timing signal for the change. Is used. That is, as shown in FIG. 2, in the present invention, the magnetic flux leakage detector 3 is provided with magnetic sensors 3b twice the number of strands at equal intervals, so that a rising edge with a strand pitch signal 22 is detected. Assuming that the 0th strand 1a-1 corresponds to the magnetic sensor 3b-1 at that time, when the next strand pitch signal 22 falls, the 0th strand 1a-1 Will correspond to 2. When the strand pitch signal 22 rises next time, the 0th strand 1a-1 corresponds to the magnetic sensor 3b-3. In this way, by sequentially shifting the corresponding magnetic sensor 3b using the rise and fall of the strand pitch signal 22, the control device 4 is damaged every time the timer 4a is instructed to start. The total of the signals 24 is calculated, delivered as strand-specific data, and stored in the rewritable memory 4d shown in FIG.
[0050]
Now, in step 15 of FIG. 8, the means for obtaining the total number of damage signals 23 included in one pitch in the longitudinal direction of the wire rope 1 for all the strands 1a is the same as that described in the first embodiment. However, the total number of the damage signals 23 included in one pitch in the longitudinal direction for each strand (1a-1 to 1a-8) is obtained as follows.
[0051]
That is, it is assumed that the damage signal 24 corresponding to a certain strand 1a appears in FIG. 9B ', for example. Therefore, as shown in FIG. 9A, in the determination range from the current rising edge of the strand pitch signal 22a to the rising edge of the strand pitch signal 22a ′ which is the number of strands (eight) ago, FIG. In step 15, the strand-specific damage signals 24 included in the range of the setting signal 25a shown in FIG.
[0052]
Next, the process proceeds to step 16 where the number of strand-specific damage signals 24 is compared with a preset reference number for replacement determination (the number of damage signals 24 is 5). As shown in FIG. 9 (b ′), in this embodiment, since the number of damage signals 24 included in the range of the setting signal 25a is 5, the determination result in step 16 is YES, and the replacement determination signal 26a. Is output, and the process proceeds to step 17 where a display indicating that the wire rope 1 needs to be replaced is displayed by the replacement determination signal 26a. However, for example, when the number of damage signals 24 included in the range of the setting signal 25a is four or less, the damage signals 23 included in one pitch for all the strands 1a described as the first embodiment. Since the total number of is less than the reference number, the determination result in step 16 is NO, and in this case, the process jumps to step 18.
[0053]
When the rising edge of the next strand pitch signal 22b is detected, a setting signal 25b having a determination range from the rising edge to the rising edge of the eight previous strand pitch signals 22b ′ is shown in FIG. The number of the damage signals 24 for each strand included in the range of the setting signal 25b is four, which is below the reference number. However, since the total number of the damage signals 23 of all the strands 1a included in the range of the setting signal 25b exceeds the reference number, the determination result is YES, the replacement determination signal 26b is output, and the process proceeds to step 17 The display 5 indicates that the wire rope 1 needs to be replaced by the replacement determination signal 26b.
[0054]
Therefore, in this embodiment, the number of damage signals 24 for each strand can be displayed on the display 5 together with the total number of damage signals 23 for all strands.
[0055]
In step 18, the total number of damage signals 23 and 24 counted in step 15 is output, and when the edge (rising or falling) of the strand pitch signal 22 is detected, step 20 corresponds to the strand 1 a. In the same manner as when the edge of the strand pitch signal is not detected in step 13 (NO) in step 21 after updating / recording the magnetic sensor 3b, damage determination is performed for each of the magnetic sensors (3b-1 to 3b-16), Further, as step 22, the damage signal 24 is delivered and stored as strand-specific data assigned to each magnetic sensor (3b-1 to 3b-16).
[0056]
Thus, in the second embodiment of the present invention, in addition to the replacement determination based on the total number of damages of all the strands described as the first embodiment, the replacement determination is also performed based on the number of damages for each strand. Therefore, the reliability of automatic diagnosis can be further improved.
[0057]
Next, the operation of the third embodiment of the wire rope flaw detector according to the present invention will be described with reference to the flowchart shown in FIG.
[0058]
In the third embodiment, in addition to the operation in the first or second embodiment, the rising edge interval of the strand pitch signal 22 is measured, and the strand pitch signal 22 counted within a predetermined time. Focusing on the fact that the number is proportional to the moving speed of the wire rope 1, the moving speed of the wire rope 1, that is, the rope speed is calculated.
[0059]
Therefore, in FIG. 10, the operation part as the third embodiment is added as the step 19 and the step 23 to the flowchart of the operation steps as the second embodiment shown in FIG. 8 does not have this step), the added part will be described mainly, and the description of the same part as in FIG. 8 will be omitted. Further, in the third embodiment, the processing device 4 is provided with a function as a rope speed counter, and it is necessary to add an initial value of the strand pitch as preset data. Here, the initial value of the strand pitch is set to 9 mm, for example. The number of strands 1a is 8, the diameter of the wire rope is 12 mmφ, and the start command interval of the timer 4a is 1 ms.
[0060]
The processing device 4 increments the rope speed counter as step 23 every time it receives a start command of the timer 4a. In step 19, the rope speed is calculated. In this calculation, the number of strand pitch signals 22 detected during the start command interval (1 ms) of the timer 4a is multiplied by the start command interval of the timer 4a to the rope speed counter, and the strand pitch initial value is divided by the result. It is. The result thus obtained is stored as the rope moving speed, and is output to the display 5 so that the rope speed counter is reset.
[0061]
Thus, in this embodiment, the number of strand pitch signals 22 counted per unit time can be calculated and displayed every moment, paying attention to the fact that the number of strand pitch signals 22 is proportional to the rope speed. The equipment can be used effectively without the need for special equipment. Also, by comparing the measured speed of the wire rope 1 with, for example, the rotational speed of a drive unit such as a sheave of an elevator apparatus using the wire rope, if there is a large difference, the wire rope will grow due to secular change. It can also be determined that The rope speed calculation method has been described as counting the interval of the strand pitch signal 22 at the start command interval of the timer 4a, but is not limited to this, and the strand pitch signal is calculated at a predetermined time interval. Needless to say, 22 may be counted and the result multiplied by the initial value of the strand pitch and divided by a predetermined time interval.
[0062]
Needless to say, the present invention is not limited to the above-described embodiment, and can be implemented in various forms.
[0063]
For example, the contents displayed on the display 5 include a message indicating whether or not replacement is required as a result of the wire rope replacement determination, the number of damages for all strands, the number of damages for individual strands, and the rope speed. I just need it. Furthermore, by installing the indicator 5 on the side of the driver of the device using the wire rope, the driver of the device using the wire rope can recognize the state of damage to the wire rope. As well as being able to serve as a worker who operates the wire rope flaw detector, the wire rope flaw detection diagnosis can be carried out efficiently.
[0064]
In addition, in each embodiment, the damage determination, replacement determination, strand replacement reference value and strand pitch initial value are all examples, and depend on the type of wire rope, the rope diameter, and the number of strands. It changes greatly and is not particularly limited. Furthermore, although the permanent magnet was used as the magnetizer 2 that magnetizes the wire rope, an electromagnet may be used. And although the planar thing was arrange | positioned as the magnetic sensor 11, this is not specifically limited, either, For example, planar solid is smaller than the longitudinal and circumferential pitch width of the strand 1a. As the magnetic sensor, a Hall element, an electromagnetic induction type coil-type magnetic sensor or the like can be used.
[0065]
【The invention's effect】
As described in detail above, according to the present invention, it is possible to provide a wire rope flaw detector that exhibits extremely remarkable effects.
[0066]
That is, according to the first aspect of the present invention, since it is possible to automatically determine whether or not the wire rope needs to be replaced, it is possible to significantly reduce the confirmation time by visual inspection such as wire wire breakage or internal wire breakage. Thus, the damage detection operation can be made extremely efficient.
[0067]
In addition, according to the invention described in claim 2, it is possible to more efficiently perform the wire rope replacement work by finding a damaged strand among the strands and determining whether or not the wire rope needs to be replaced. it can.
[0068]
Moreover, according to the invention of Claim 3, the advancing speed of a wire rope can be detected, without installing special apparatus additionally. In addition, by comparing with the rotational speed of the wire rope drive unit such as a sheave, it is possible to determine that the wire rope has been aged over time when there is a large difference.
[Brief description of the drawings]
FIG. 1 is a perspective view showing an overall image of an embodiment of a wire rope flaw detector according to the present invention.
2 is a cross-sectional view of the leakage flux detector of the wire rope flaw detector shown in FIG. 1 cut along a plane perpendicular to the wire rope. FIG.
FIG. 3 is an explanatory diagram of a magnetic sensor provided in a leakage magnetic flux detector.
FIG. 4 is a block diagram showing a schematic configuration of an embodiment of a processing apparatus.
FIG. 5 is a flowchart showing operation steps in the first embodiment of the present invention.
FIG. 6 is a timing chart showing various signals based on detection signals obtained from a magnetic sensor.
FIG. 7 is a timing chart of various signals shown to explain the operation of the first exemplary embodiment.
FIG. 8 is a flowchart showing operation steps in the second embodiment of the present invention.
FIG. 9 is a timing chart of various signals shown to explain the operation of the second embodiment.
FIG. 10 is a flowchart showing operation steps in the third embodiment of the present invention.
FIG. 11 is a perspective view showing an overall image of a conventional wire rope flaw detector.
[Explanation of symbols]
1 Wire rope
1a strand
2 Magnetizer
3 Leakage magnetic flux detector
3b Magnetic sensor (magnetic detection means)
4 processing equipment
4a timer
5 Display
22 Strand pitch signal
23, 24 Damage signal
25a, 25b Setting signal
26a, 26b Exchange determination signal

Claims (4)

A magnetizing means for magnetizing a wire rope formed by twisting a plurality of strands in a longitudinal direction;
A plurality of magnetic detection means arranged to correspond to each of the plurality of strands in the circumferential direction of the wire rope;
A damage signal detection means for deriving a damage signal when the magnetic force detected by the magnetic detection means exceeds a predetermined reference value;
A strand pitch signal output means connected to the magnetic detection means for obtaining a strand pitch signal of the wire rope that moves relatively;
The strand pitch signal sums the number of damage signals each of said plurality of magnetic sensing means which is derived from the previous SL damage signal detecting means while being counted by a predetermined number, the reference to the total number of predetermined Determining means for determining whether or not the number has been exceeded;
A wire rope flaw detector characterized by comprising: A magnetizing means for magnetizing a wire rope formed by twisting a plurality of strands in a longitudinal direction;
A plurality of magnetic detection means arranged to correspond to each of the plurality of strands in the circumferential direction of the wire rope;
A damage signal detection means for deriving a damage signal when the magnetic force detected by the magnetic detection means exceeds a predetermined reference value;
A strand pitch signal output means connected to the magnetic detection means for obtaining a strand pitch signal of the wire rope that moves relatively;
While the strand pitch signal is counted by a predetermined number, the total number of the damage signals for each strand is obtained from the damage signal derived from the damage signal detection means, and the total number is a predetermined reference number. Determining means for determining for each strand whether or not exceeded,
A wire rope flaw detector characterized by comprising: 3. The wire rope flaw detector according to claim 1, wherein the magnetic detection means is formed in a shape shorter than a circumferential width and a longitudinal pitch of one strand of the wire rope. .   The rope speed calculating means for calculating the moving speed of the wire rope by counting the strand pitch signal for a predetermined time is provided. Wire rope flaw detector.

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