JP2019085242A - Elevator rope inspection system - Google Patents

Abstract

The present invention improves the operational life of a rope in a state where rope strength is ensured and improves the reliability of strength management during maintenance and inspection of ropes in which damage to tensile strength materials is not visible. An elevator rope inspection system according to one embodiment includes a mark detection sensor 21, a tension detection device 40, and an arithmetic device 23. The mark detection sensor 21 detects a plurality of marks provided at regular intervals in the longitudinal direction of the main rope 10 to be inspected. Tension detection device 40 detects the tension of main rope 10. The calculation device 23 calculates the amount of elongation of the main rope 10 from the interval between each mark, corrects the amount of elongation to the amount of elongation under a constant tension based on the tension of the main rope 10, and calculates the amount of elongation after the correction. Strength management is performed based on this. [Selection diagram] Figure 1

Description

  An embodiment of the present invention relates to a rope inspection system for inspecting a deterioration state of a wire rope used for an elevator main rope or the like.

  BACKGROUND In recent years, wire ropes in which the surface of a tensile strength member is coated with a resin material having wear resistance and a high friction coefficient such as polyurethane are in widespread use. In this type of wire rope, the strength member inside can not be visually checked, and strength management can not be performed by visual inspection of the worn state of the wire and the number of breaks. For this reason, for example, a method of energizing a wire and measuring a change in electrical characteristics due to aging deterioration, or a method of disposing a conductive member which degrades ahead of a tensile strength member inside a rope and measuring its conduction state Is used. However, the former method is limited to the rope structure in which the tensile member has few strands, such as a steel cord. The latter method is applicable to wire ropes with aramid fibers and resin coating, but increases the manufacturing cost because the rope structure is complicated.

  Here, as another method, there is a method of marking the surface of a long object such as a rope at a constant interval and determining the state of elongation from the interval of these marks at the time of inspection.

Japanese Patent Application Publication No. 2005-512921

  In the strength management of the rope in the elevator, with the elongation of the rope due to the secular change, the point in time when the remaining strength of the rope falls below the reference value is defined as the replacement time. However, rope elongation includes elastic elongation due to tension acting on the rope in addition to elongation due to aging. It is difficult to detect the elastic elongation due to this tension separately from the elongation due to aging. For this reason, usually, in anticipation of safety, the rope is replaced early in consideration of the elastic elongation which is supposed to occur at the time of inspection.

  The problem to be solved by the present invention is to improve the operational life in the state where the rope strength is secured and improve the reliability of strength management in the maintenance inspection of the rope where the damage of the tensile strength material is not visible. To provide an elevator rope inspection system capable of

  A rope inspection system for an elevator according to one embodiment comprises: mark detection means for detecting a plurality of marks provided at regular intervals in the longitudinal direction of a rope to be inspected; tension detection means for detecting tension of the rope; The stretch amount of the rope is calculated from the interval between the marks detected by the mark detection means, and the stretch amount of the rope under constant tension based on the tension of the rope detected by the tension detection means The expansion amount is corrected, and calculation means is provided to perform strength management based on the corrected expansion amount.

FIG. 1 is a view showing a schematic configuration of a machine room-less type elevator according to the first embodiment. FIG. 2 is a cross-sectional view showing a structure of a main rope used for the elevator in the same embodiment. FIG. 3 is a perspective view showing an appearance of a main rope used for the elevator in the embodiment. FIG. 4 is a side view of the mark detection sensor in the embodiment. FIG. 5 is a view of the mark detection sensor in the same embodiment as viewed obliquely from behind. FIG. 6 is a view showing a state in which the mark detection sensor in the same embodiment is provided as a pair on both sides of the main rope. FIG. 7 is a flowchart for explaining the operation of the rope inspection system in the embodiment. FIG. 8 is a view for explaining the relationship between the pulse signal and the mark interval in the embodiment, and FIG. 8 (a) is a pulse signal output in synchronization with the movement of the main rope, and FIG. 8 (b) is an installation. The mark interval of time, FIG. 6C shows the mark interval when the rope is stretched due to the secular change. FIG. 9 is a view showing the relationship between the reflected light intensity and the frequency obtained from the mark detection sensor in the second embodiment. FIG. 10 is a view showing the relationship between the elongation and the residual strength due to the deterioration of the rope. FIG. 11 is a diagram showing the results of simulation of how the rope tension changes with respect to the car position. FIG. 12 is a diagram for explaining the shift of the elongation percentage determination reference in consideration of the variation in tension of the rope.

  First, before making the embodiment of the present invention, the relationship between the elongation percentage and the strength of the rope will be described with reference to FIGS. 10 to 12.

  For example, in a wire rope used for an elevator main rope or the like, the tensile members such as a strand and a core are squeezed by tension and rub against each other by bending received from a sheave or the like. For this reason, the form of rope deterioration is dominated by the wear and breakage of the strands in the vicinity of the heart cord (the part surrounded by the dotted line in FIG. 2). The deterioration of this portion causes the strands to move in the direction of the core (in the direction in which the rope diameter decreases), resulting in an elongation as a wire rope structure.

  As a result of conducting a verification on a wire rope having such a structure, it was found that there is a correlation as shown in FIG. 10 between the elongation rate and the strength. In FIG. 10, the horizontal axis represents the elongation of the rope. Although specific numerical values will be omitted in terms of security, λ in the figure is about several%, and the distance is about several mm. The vertical axis represents the strength factor of the rope (this is called the residual strength factor). As the rope gradually grows from the new condition at the time of installation due to aging, the strength also decreases accordingly. Usually, the strength rate of 80% is defined as a reference strength, and safety can be obtained by using a point in time when the elongation rate of the rope becomes λ as the replacement time.

  However, the elongation of the rope due to aging includes elastic elongation in addition to the reduction in the spiral radial direction due to the wear of the strands and the core. The properties of elongation and strength of the rope shown in FIG. 10 are the properties obtained by the bending endurance test under constant tension. When the tension is removed, although the structural elongation accompanying the reduction of the helical radius remains, the elastic recovery of the structural shape causes gaps in parts such as strands and strands, so that a stable amount of elongation can not be obtained.

  Even in maintenance inspections, it is desirable to measure the amount of elongation under the same tension as in the endurance test as in the characteristics of FIG. 10, but it is difficult to apply a constant tension to each of the multiple ropes that make up the rope . The reason is that in elevator systems generally using multiple ropes, a constant level of tension variation is inevitable. This causes a difference in elastic elongation of the ropes, and the feed amount of each rope sent by the sheave differs according to the tension, and as a result, the tension state of the ropes along with the lifting operation of the elevator (car) Changes.

  The result of having simulated the mode of tension change of five ropes to a car position in Drawing 11 is shown. As a condition, ± 2.5% and ± 5% of the average tension are set to the other ropes with respect to the No 3 rope under the average tension at the bottom floor at the stroke of 20 m.

  With the exception of the No. 3 ropes under average tension, the tension of each rope changes in a closed loop as the car moves up and down, and the vertical relationship is reversed between the bottom floor and the top floor. ing. Furthermore, the fluctuation range of tension increases when moving to the final floor (the top floor in FIG. 11), and exceeds ± 5% of the initial level.

  The variation width (variation range) of the tension depends on the variation range after tension adjustment which is initially set, the elevation stroke, the sheave groove radius, the variation of the rope diameter, and the like. The closed loop curve indicating the tension change of each rope is substantially constant if the loading condition does not change, but changes when the loading condition changes, and converges to a constant curve by continuing the same loading condition.

  In an elevator system having such tension variation due to tension variation, sheave diameter, and rope variation, there has been no method for performing maintenance inspection based on the elongation percentage-remaining strength characteristic of FIG.

  In Patent Document 1 described as a prior art document, the tension state is grasped by measuring the torque of the hoist with respect to the change in tension and the change in load of the belt due to the position change of the car. The method of correcting the amount of expansion of the is shown (see paragraphs [0045]-[0046]). However, what is corrected by this method is the amount of elongation relative to the change in average tension. When the variation in tension is large, the amount of extension for the tension change resulting from this can not be corrected.

  In order to perform strength management with the expansion standard of replacement standard obtained by the elongation percentage-remaining strength characteristic, under the present circumstances, as shown in FIG. 12, it is assumed that it occurs at the time of inspection in anticipation of safety. It is necessary to apply an elongation rate λ 'in consideration of the elastic elongation fraction δλ. For this reason, even when the rope strength is equal to or higher than the reference value, it is replaced early, and as a result, the operational life is shortened.

  Embodiments will be described below with reference to the drawings.

First Embodiment
FIG. 1 is a view showing a schematic configuration of a machine room-less type elevator according to the first embodiment.

  The elevator 1 has a hoistway 2 provided in a building, in which a car 11 and a counterweight 12 are supported so as to be movable up and down via guide rails. Furthermore, a hoisting machine 14 with a traction sheave 13 is installed at the top of the hoistway 2.

  The car 11 and the counterweight 12 are suspended in the hoistway 2 via a plurality of main ropes 10. In FIG. 1, only one main rope 10 is shown, and the other main ropes 10 are not shown.

  One end 3a and the other end 3b of the main rope 10 are fixed to the upper end of the hoistway 2 via rope hitches 4a and 4b, respectively. Further, the middle portion 3c of the main rope 10 is continuously wound around the sheave 15 provided on the car 11, the traction sheave 13 provided on the hoisting machine 14 and the sheave 16 provided on the counterweight 12 . Thus, the car 11 and the counterweight 12 are supported in a 2: 1 low pink format. When the traction sheave 13 is rotated by the driving of the hoisting machine 14, the car 11 and the counterweight 12 are lifted and lowered in the hoistway 2 via the main rope 10 along with the rotation of the traction sheave 13.

  Further, a governor (governor) 17 is provided in the hoistway 2. Reference numeral 18 in the figure denotes a governor rope for rotationally driving the governor 17. The speed governor 17 detects the position and speed of the car 11 via the governor rope 18 which moves along with the raising and lowering operation of the car 11 and brakes when the speed of the car 11 exceeds the set speed due to some abnormality. Launch

  In the machine room-less type elevator without machine room, the hoisting machine 14 is installed in the hoistway 2, but the present invention is not particularly limited to this configuration, and is an elevator having a machine room May be In an elevator having a machine room, the hoisting machine 14 is installed in the machine room. Further, the roping is not limited to the 2: 1 roping as shown in FIG. 1, but may be another method such as, for example, 1: 1 roping.

  Here, the rope inspection system of the present embodiment includes the mark detection sensor 21, the encoder 22, the arithmetic device 23, the display device 24, and the tension detection device 40.

  The mark detection sensor 21 detects a plurality of marks 20 (see FIG. 3) provided at regular intervals in the longitudinal direction of the main rope 10 to be inspected. The encoder 22 is provided to the governor 17. The encoder 22 generates a pulse signal in synchronization with the movement of the main rope 10 as the elevator car 11 moves up and down.

  The arithmetic unit 23 counts pulse signals generated from the encoder 22 between the marks 20 detected by the mark detection sensor 21 at the time of inspection, and calculates the amount of extension of the main rope 10 from the count value. Furthermore, in the present embodiment, the computing device 23 uses the tension detected by the tension detection device 40 and the elastic modulus of the main rope 10 to stretch the main rope 10 calculated above under constant tension. Correction and control the strength based on the corrected amount of expansion. The display device 24 displays the amount of extension (distance between marks) of the main rope 10 obtained by the arithmetic device 23 and the like. Arithmetic unit 23 and display unit 24 consist of general purpose computers.

  The tension detection device 40 is provided at an end of the main rope 10, and detects the tension of the main rope 10 using a load cell provided with a strain gauge or the like inside. In the example of FIG. 1, the tension detection device 40 is provided at one end 3a of the main rope 10 on the side of the car 11, but the tension detection device 40 is provided on the other end 3b of the main rope 10 on the counterweight 12 side. May be provided.

  Here, the structure of the main rope 10 will be described with reference to FIGS. 2 and 3.

  A wire rope is used as the main rope 10. As shown in FIG. 2, the main rope 10 is provided with a rope main body 31 as a tensile strength member and an outer covering layer 32 entirely covering the rope main body 31 as main elements.

  The rope body 31 is configured by twisting a plurality of steel strands 33 at a predetermined pitch centering on a core rope 30. The outer covering layer 32 is formed of, for example, a thermoplastic resin material having wear resistance and a high friction coefficient, such as polyurethane. The outer covering layer 32 has an outer circumferential surface 32 a that defines the outer surface of the main rope 10. The outer peripheral surface 32a has a circular cross-sectional shape, and contacts with friction when being wound around each of the sheaves 13, 15, 16.

  Furthermore, the resin material forming the outer covering layer 32 is filled in the gap between the adjacent strands 33. Therefore, the outer covering layer 32 has a plurality of filling parts 34 which enter between the adjacent strands 33 in the circumferential direction of the rope body 31. The filling portion 34 is located inside the outer peripheral surface 32 a of the outer covering layer 32.

  As shown in FIG. 3, a plurality of marks 20 are provided on the surface of the main rope 10 (that is, the outer peripheral surface 32 a of the outer covering layer 32). These marks 20 are elements for detecting the amount of extension due to the deterioration of the main rope 10, and are arranged at regular intervals (for example, 500 mm intervals) in the longitudinal direction over the entire length of the main rope 10. Each one of these marks 20 is formed by a continuous straight or intermittent dotted line in the circumferential direction of the main rope 10.

  By the way, in the main rope 10, the gap between the strands 33 and the gap between the plurality of strands forming the strands 33 decrease with the passage of use period. As a result, the strands 33 and the strands repeat friction with each other, and wear and breakage of the strands 33 and the strands progress.

  In particular, at portions where the main rope 10 contacts the sheaves 13, 15, 16, friction is repeatedly received. For this reason, the degree of progress of wear and breakage of the main rope 10 is larger than that of the portion where the main rope 10 does not pass through the sheaves 13, 15 and 16, thereby reducing the rope diameter of the main rope 10 or the main rope 10 Local growth occurs. Therefore, the strength of the main rope 10 can be managed by clarifying the relation between the elongation of the main rope 10 and the strength reduction rate and detecting the elongation of the portion of the main rope 10 where the deterioration is the largest.

  The mark detection sensor 21 is fixed so as to face the main rope 10 in the vicinity of the hoisting machine 14, for example. As a result, when the car 11 is raised and lowered between the top floor and the bottom floor in the inspection operation, most of the entire length of the rope 10 passes the mark detection sensor 21 except the portions near the rope hitch 4a and 4b. The mark 20 can be detected continuously during the passage. Further, since the encoder 22 outputs a pulse signal in synchronization with the movement of the car 11, the pulse output substantially corresponds to the rope feed amount.

  The arithmetic unit 23 uses the mark detection signal output from the mark detection sensor 21 as a trigger, counts the number of pulse signals output from the encoder 22 during that time, and extends the distance between the marks from the count value by a rope Calculated as a quantity.

  The position near the hoisting machine 14 for fixing the mark detection sensor 21 may be on the side of the car 11 or on the side of the counterweight 12. In the case of the counterweight 12 side, since the rope tension does not depend on the loading state of the car 11, the threshold value for the replacement determination becomes constant with respect to the specific structure, and the operational convenience is high. This is because the elastic elongation of the main rope 10 is different due to the difference in mass between the car 11 and the counterweight 12, and different elongations are shown for a certain deterioration. However, this is not an essential problem in the measurement of the mark interval because the threshold value for the replacement determination may be changed in accordance with the rope tension.

  The mark detection sensor 21 is preferably configured as a photoelectric sensor using laser reflected light in view of responsiveness. Among commercially available photoelectric sensors, in recent years, a sensor that irradiates laser light to an object and detects a change in surface color based on a difference in reflected light intensity has become widespread.

  FIG. 4 and FIG. 5 are diagrams showing the basic configuration in the case of optically detecting the mark 20 on the main rope 10 by the mark detection sensor 21. As shown in FIG. FIG. 4 is a view of the mark detection sensor 21 as viewed from the side, and FIG. 5 is a view of the mark detection sensor 21 as viewed obliquely from behind. Here, a configuration in which one mark detection sensor 21 is disposed on one side of the main rope 10 is shown, but in consideration of the case where a part of the mark 20 is missing, a pair is provided on both sides of the main rope 10 as described later. Preferably, the mark detection sensor 21 is disposed.

  The mark detection sensor 21 includes an irradiation unit 25 for irradiating a laser beam, and a light receiving unit 26 for receiving reflected light. The light receiving unit 26 has detection sensitivity to the reflected light within the range indicated by the broken line A in the longitudinal direction of the main rope 10. Therefore, when the mark 20 is irradiated with a laser beam, the light receiving unit 26 detects a strong reflected light, and the presence or absence of the mark 20 can be determined from the intensity of the reflected light.

  If the moving speed of the main rope 10 is an inspection operation of 1 m / s or less, sufficient response performance can be obtained, and the cost is low compared to the detection method by the image processing camera as in the prior art 1. Furthermore, in the detection method by the image processing camera, the mark interval can not be measured from the photographed image unless the camera is installed at a place away from the main rope 10 and the main rope 10 is photographed in a wide range. On the other hand, in the present embodiment, since the mark detection sensor 21 may be installed near the main rope 10, there is an advantage that the rope inspection environment is not widely required.

  Here, the determination threshold value of the reflected light intensity in the mark detection sensor 21 is configured to be variable at the time of inspection. This is because the mark 20 and the rope surface condition that affect the laser reflected light intensity change over time.

  For example, when part of the mark 20 is lost, it is necessary to increase the detection sensitivity in order to reduce the reflected light intensity. In addition, it is necessary to lower the detection sensitivity when (light-colored) deposits that are likely to reflect light are fixed to the rope surface. Since the state of the rope surface differs depending on the use condition of the elevator, by making the determination threshold adjustable according to the state for each property, it is possible to prevent false detection and omission of detection of the mark 20.

  Although the mark 20 provided on the surface of the main rope 10 has been described as having a high reflected light intensity, it is essential that the portion (mark portion) where the mark 20 is provided in the main rope 10 and the mark 20 be provided. The reflected light intensity may be different from the non-marked portion (non-marked portion), and the function is the same even if the reflected light intensity is decreased in the mark portion.

  Moreover, in order to detect the mark 20 which the main rope 10 has autorotation and lose | eliminates one part over time reliably, it is necessary to have a detection sensitivity with respect to the rope whole circumference. Therefore, as shown in FIG. 6, it is preferable to provide a pair of mark detection sensors 21 so as to sandwich the main rope 10 from both sides.

  In this case, in order to suppress an increase in the number of sensors, the irradiation range of the main rope 10 of the laser light of one mark detection sensor 21 in the diameter direction and the light reception range of the reflected light in the horizontal direction are shown in FIG. As shown, a configuration that approximately matches the diameter B of the main rope 10 is desirable. Because it is necessary to have sensitivity to the minimum rope width at least in order to prevent detection leak of mark 20, but when it is made wider than the rope width, the reflection from the structure behind the main rope 10 etc. And the possibility of false detection is increased.

  Next, the operation of this system will be described.

  FIG. 7 is a flow chart for explaining the operation of this system, and shows the processing of automatically measuring the interval of the marks 20 by the inspection operation to determine the deterioration state of the main rope 10.

  First, the car 11 is moved to the lower floor, and from there, the inspection operation is started toward the uppermost floor (step S11). The car 11 may be inspected and operated from the top floor to the bottom floor. By this inspection operation, the main rope 10 hanging the car 11 and the counterweight 12 is slowly moved at a constant speed. At this time, a pulse signal is output from the encoder 22 in synchronization with the movement of the main rope 10. Arithmetic unit 23 sequentially counts the number of pulse signals output from encoder 22 (step S12).

  Further, along with the movement of the main rope 10, the marks 20 provided on the surface of the main rope 10 are optically detected by the mark detection sensor 21. Arithmetic unit 23 confirms the count value of the pulse signal at the present time at the timing when mark 20 is detected by mark detection sensor 21, and calculates the distance between the marks based on the count value (step S14).

  Specifically, the arithmetic unit 23 counts the number of pulse signals generated from the encoder 22 while the mark detection sensor 21 detects the mark 20, and the count value and the rope movement amount per pulse (pulse rate) Calculate the distance between marks based on Data indicating the distance between the marks calculated at this time is stored in the memory 23a (FIG. 1) in the arithmetic unit 23. In this case, if the main rope 10 is not stretched, the calculated distance between the marks is the same as the mark interval (for example, 500 mm) attached to the main rope 10 at the time of installation. When the main rope 10 extends due to aging, the calculated distance between the marks becomes larger than the mark interval at the time of the installation.

  After that, similarly, until the car 11 reaches the top floor, the count value of the pulse signal is confirmed at the detection timing of the mark 20, and the distance between the marks is sequentially calculated from the count value and stored in the memory 23a. It memorizes (Steps S12-S15).

  As a method of counting pulse signals, there are a method of integrating one pulse at a time from an initial value (for example, "0000") and a method of resetting to an initial value and repeating counting each time a mark is detected. In the case of the former method, the difference value between the integrated value of the pulse when the mark 20 is detected and the integrated value of the pulse when detected last time is determined, and the distance between the marks is determined from the difference value. Become.

  In order to associate the rope position with the car position, it is preferable to integrate one pulse at a time from the initial value as in the former method. In this case, if the integrated value of the pulse when the mark 20 is detected is sequentially stored, the portion of the main rope 10 to be checked is marked if the car 11 is moved using the integrated value as an index later. It can be visually observed at the installation place of the detection sensor 21.

  In the case of 2: 1 roping, for example, the amount of car movement obtained by the encoder 22 provided in the governor 17 is 1/2 of the amount of rope movement. Therefore, in order to obtain the mark interval from the count value of the pulse signal, it is necessary to consider the ratio of the roping at that time.

  Here, at the time of elevator installation, the marks 20 are arranged at equal intervals in the longitudinal direction of the main rope 10. Therefore, when there is no elongation due to deterioration of the main rope 10, the count value of the pulse signal becomes substantially the same as the reference value corresponding to the mark interval at the time of installation. On the other hand, when the main rope 10 is stretched due to the deterioration of the main rope 10, the count value of the pulse signal exceeds the reference value corresponding to the mark interval at the time of installation.

  This situation is shown in FIG.

  8A and 8B are for explaining the relationship between the pulse signal and the mark interval, and FIG. 8A is a pulse signal output in synchronization with the movement of the main rope 10, and FIG. 8B is the mark interval at the time of installation. The same figure (c) is mark interval at the time of rope extension by secular change.

  Assuming that the reference value when counting the pulse signal at the mark interval at the time of installation is n pulses, when the main rope 10 is not deteriorated, the count value obtained in the inspection operation is slightly different from the n pulse at the time of installation And the same. However, when the main rope 10 is in a stretched state due to deterioration, the count value obtained in the inspection operation is larger than n pulses corresponding to the mark interval at the time of installation.

  After the inspection operation, the arithmetic unit 23 calculates the amount of extension of the main rope 10 based on the distance between the marks stored as the measurement result in the memory 23a (step S16). As described above, rope elongation at the time of inspection includes elastic elongation due to tension in addition to the elongation due to aging deterioration. Therefore, the arithmetic unit 23 corrects the amount of elongation calculated in step S16 to an amount of elongation under a constant tension in consideration of the elastic elongation due to the tension (step S17).

Specifically, assuming that the number of pulse signals generated from the encoder 22 while the mark detection sensor 21 detects a mark is Cn, the distance D between the marks is
D = Cn × γ .. (1)
Is required.

  γ is a pulse rate, which is a rope feed amount per pulse synchronized with the car movement amount.

  Here, in accordance with the tension T when the main rope 10 passes the mark detection sensor 21, the main rope 10 is elastically stretched. Therefore, by detecting the tension at the time of inspection by the tension detection device 40, the elongation amount d at the standard tension T0 is obtained using the following equation.

d = D + (T0-T) / k-D0 .. (2)
Where k = AE / D0
k is the spring constant (elastic modulus) of the rope with respect to the mark interval D0 at no load. A is the cross section of the rope and E is the elastic modulus of the rope.

  By using the equation (2), the elongation percentage て も at the standard tension T0 can be obtained by the following equation, regardless of the tension state of the rope to be inspected.

Λ = d / D 0 .. (3)
Λ is the same elongation rate under constant tension as the bending endurance test. The elastic elongation amount included in the elongation amount of the rope can be regarded as equivalent to the deteriorated sample which determines the replacement standard, and therefore, can be controlled by the elongation rate λ in the elongation rate-residual strength characteristic shown in FIG. That is, the main rope 10 having safety in terms of strength can be used for a longer time than the management of λ ′ as a replacement standard in anticipation of tension fluctuations shown in FIG. 12, and the operational life can be improved.

  Arithmetic unit 23 determines that the strength of main rope 10 is reduced to a standard value or less, that is, in a deteriorated state, when the corrected expansion amount d exceeds a preset threshold (step S18). The threshold value corresponds to the elongation rate λ shown in FIG. As described above, the elongation rate λ is several%, and the distance is several mm. That is, when the amount of extension d after the correction exceeds the amount of extension corresponding to the extension ratio λ, it is determined that the main rope 10 is in the deteriorated state.

  If it is determined that the main rope 10 is in a deteriorated state, the computing device 23 displays a warning message on the display device 24 or emits an alarm sound, for example, to indicate that the rope replacement time is approaching the maintenance personnel. Inform. Thereby, the inspection work by the maintenance staff can be reduced, and it is possible to grasp and cope with the time when the rope needs to be replaced.

  Further, since it is easy to associate the measured value of the mark interval of each part from the count value of the pulse signal with the rope movement amount by the inspection operation, the rope position of the location exceeding the above threshold is displayed on the display 24. It is good. Where the mark interval exceeds the threshold value, the damage has progressed, and in order to clarify the cause of the damage, visual confirmation of the damage level is desired by visual observation. In such a case, the confirmation operation is facilitated by displaying the rope position at the point where the threshold value is exceeded.

  Alternatively, the display unit 24 may display a rope position at which the main rope 10 extends the most, that is, the mark position with the largest mark interval. In general, the portion where the main rope 10 is largely deteriorated is the portion where the bending load associated with the floor where the stopping frequency of the car 11 is high is maximized. However, for example, if there is a portion damaged accidentally at the time of installation etc., deterioration of the damaged portion may precede. By displaying the rope position of the maximum elongation portion, it becomes easy to confirm the deteriorated portion different from such normal deterioration.

  Alternatively, the mark measurement result may be recorded as history information in the memory 23a, and the history information may be displayed graphically for each inspection date. In this way, the state of the rope deterioration can be easily grasped from the change of the mark interval.

  Furthermore, if the above history information is periodically sent to an elevator monitoring center at a remote location not shown, the elevator monitoring center side can centrally manage the deterioration state of the main rope 10 of each property, and the rope replacement time It is possible to notify maintenance staff of nearby properties.

  As described above, according to the first embodiment, appropriate strength management can be performed by correcting the amount of elongation obtained from the interval of the marks attached to the rope to be inspected to the amount of elongation under a constant tension. it can. As a result, it is possible to improve the operational life in the state where the rope strength is secured, and to improve the reliability of strength management.

Second Embodiment
Next, the second embodiment will be described. It is desirable from the viewpoint of accuracy to use a load cell internally provided with a strain gauge or the like as the tension detection device 40, but the mark detection sensor 21 is shared as a tension sensor from the viewpoint of cost reduction. It is also possible.

  As described in FIGS. 4 and 5, a photoelectric sensor is used as the mark detection sensor 21. As a general detection method of a photoelectric sensor, a method of irradiating an object with visible light or infrared light and detecting a change in the surface due to a mark or the like based on a difference in reflected light intensity has become widespread.

  In the mark detection method using the photoelectric sensor configured as described above, when lateral roll is applied to the main rope 10, the reflected light intensity fluctuates. When the time waveform of the reflected light intensity obtained from the mark detection sensor 21 is subjected to FFT (fast Fourier transform) processing, a string vibration waveform in which a dominant frequency appears at constant intervals as shown in FIG. 9 is obtained.

  The natural frequency 弦 of the string vibration is expressed by the following equation.

== n / (2L) × √ (T / ρ) (n = 1, 2, 3,...) .. (4)
L is the length of the chord, T is the tension, and ρ is the rope density. The "string length" is the length of the main rope 10 corresponding to the car position (see FIG. 1), and the value of L can be obtained by counting the pulse signals of the encoder 22. Also, the value of ρ is known.

  It is easy to excite the main rope 10 at any car position. At this time, if the waveform of the reflected light intensity of the mark detection sensor 21 is subjected to FFT processing to determine the roll vibration frequency of the main rope 10, the tension T of the main rope 10 can be obtained from the equation (4). The series of processes are executed by the arithmetic unit 23.

  In addition, the dispersion | variation in tension | tensile_strength of each rope which comprises the main rope 10 of an elevator arises by the difference in the amount of feed of a rope. When attention is paid to a specific rope, the larger the moving distance of the car 11, the larger the change width. In the case of a car-side rope, generally, when the car 11 moves to the top floor, the variation width of tension of each rope becomes maximum. In addition, although the change in tension becomes large near the top floor, this is because the difference in the amount of rope feed is stored in the rope which has become short. Therefore, reduction of the spring constant of rope hitch 4a, 4b (refer to Drawing 1) is effective in control of tension change width. This is considered to be the same effect as extending the rope shortened on the top floor.

  However, even if the spring constant is reduced, the number of elevations until the change in tension converges to a substantially constant closed loop curve increases. In any case, after the tension state (loading state) is determined, a plurality of lifting operations are required until the tension change becomes substantially constant. Therefore, in order to obtain a highly reliable amount of extension, it is preferable to adjust the loading state of the car 11 to a predetermined condition (no load) at the time of inspection and to detect tension after raising and lowering the car 11 a plurality of times. .

  As described above, according to the second embodiment, by using the mark detection sensor as a tension sensor, it is possible to obtain the tension of the rope according to the car position. Thus, as in the first embodiment, the strength management can be performed by correcting the amount of extension of the rope in consideration of the elastic elongation due to the tension.

  According to at least one embodiment described above, in maintenance inspection of the rope where damage to the tensile strength material is not visible, the operational life in a state where the rope strength is secured is improved, and the reliability of strength management is improved. It is possible to provide an elevator rope inspection system that can be

  In the example of FIG. 1, although the pulse signal output from the encoder 22 provided in the speed governor 17 is counted, for example, the same encoder is provided on the traction sheave 13 and the pulse output from the encoder It may be configured to count signals. In addition, an encoder may be fixed to the upper portion of the car 11 and the rotating portion of the encoder may be in pressure contact with the guide rail. Although these are rotary encoders, for example, a linear encoder (not shown) that outputs a pulse magnetically or optically in the hoistway 2 along the elevating direction of the car 11 may be used.

  In summary, although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and the gist of the invention, and are included in the invention described in the claims and the equivalent scope thereof.

  DESCRIPTION OF SYMBOLS 1 ... elevator, 2 ... hoistway, 3a ... one end of a rope, 3b ... the other end of a rope, 3c ... a rope middle part, 4a, 4b ... a rope hitch, 5 ... a guide rail, 10 ... a main rope, 11 ... a car, 12: counter weight, 13: traction sheave, 14: hoisting machine, 15, 16: sheave, 17: governor, 18: governor rope, 20: mark, 21: mark detection sensor, 22: encoder, 23: arithmetic device , 23a: memory, 24: display device, 25: irradiation unit, 26: light receiving unit, 30: core, 31: rope body, 32: outer covering layer, 32a: outer peripheral surface, 33: strand, 34: filling portion, 40 ... tension detection device.

Claims (7)

Mark detection means for detecting a plurality of marks provided at regular intervals in the longitudinal direction of the rope to be inspected;
Tension detection means for detecting the tension of the rope;
The stretch amount of the rope is calculated from the interval between the marks detected by the mark detection means, and the stretch amount of the rope under constant tension based on the tension of the rope detected by the tension detection means A rope inspection system for an elevator, comprising: computing means for correcting the amount of elongation and performing strength management based on the amount of elongation after the correction. The mark detection means
The resin-coated surface of the rope is irradiated with a laser beam, and the optical sensor optically detects the presence or absence of each mark by the intensity of the reflected light, and has detection sensitivity to the width of the diameter of the rope. The elevator rope inspection system according to claim 1, characterized in that: The above optical sensor is
The elevator rope inspection system according to claim 2, wherein the elevator rope inspection system is installed in the vicinity of a hoisting machine that raises and lowers the car. The rope inspection system for an elevator according to claim 1, wherein said tension detecting means detects a tension of said rope using a load cell provided at an end of said rope. The above tension detection means
The elevator rope according to claim 2, characterized in that roll vibration of the rope is determined from the intensity of the reflected light obtained from the optical sensor, and tension of the rope acting on the roll vibration is detected. Inspection system. 2. The elevator rope inspection system according to claim 1, wherein said tension detection means detects tension of said rope after being moved up and down a plurality of times in accordance with a predetermined condition. Pulse generation means for generating a pulse signal in synchronization with the movement of the rope;
The above computing means
While the mark detection means detects each mark, the number of pulse signals generated from the pulse generation means is counted, and the amount of elongation of the rope is calculated using the count value and the amount of rope movement per pulse. The rope inspection system of an elevator according to claim 1, characterized in that:

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