JP6445657B1 - Elevator rope inspection system - Google Patents

Abstract

[PROBLEMS] To improve the operational life in a state in which the rope strength is ensured and improve the reliability of strength management in the maintenance inspection of the rope in which the tensile strength material cannot be visually observed.
An elevator rope inspection system according to an embodiment includes a mark detection sensor, a tension detection device, and a calculation device. 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. The tension detection device 40 detects the tension of the main rope 10. The arithmetic unit 23 calculates the extension amount of the main rope 10 from the interval of each mark, corrects the extension amount to the extension amount under a constant tension based on the tension of the main rope 10, and uses the corrected extension amount as the extension amount. Based on strength management.
[Selection] Figure 1

Description

  Embodiments described herein relate generally to a rope inspection system for inspecting a deterioration state of a wire rope used for an elevator main rope or the like.

  In recent years, a wire rope in which the surface of a tensile member is coated with a resin material having wear resistance and a high friction coefficient such as polyurethane has been widely used. This type of wire rope cannot visually check the internal tensile member, and cannot manage the strength by visual inspection of the worn state of the strands and the number of disconnections. For this reason, for example, a method of measuring the change in electrical characteristics due to deterioration over time by energizing a strand, or a method of measuring the conduction state by disposing a conductive member that deteriorates ahead of the tensile member inside the rope. Is used. However, the former method is limited to a rope structure in which the tensile member has few strands such as a steel cord. The latter method can be applied to an aramid fiber or a wire rope with a resin coating, but the rope structure becomes complicated, which increases the manufacturing cost.

  Here, as another method, there is a method in which marks are attached to the surface of a long object such as a rope at a constant interval, and an extension state is determined from the interval between these marks at the time of inspection.

JP 2005-512921 gazette

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

  The problem to be solved by the present invention is to improve the operational life in a state where the rope strength is ensured and improve the reliability of strength management in the maintenance inspection of the rope in which the tensile strength material cannot be visually observed. To provide an elevator rope inspection system.

  An elevator rope inspection system according to an embodiment includes a mark detection unit that detects a plurality of marks provided at regular intervals in a longitudinal direction of a rope to be inspected, a tension detection unit that detects tension of the rope, The rope extension amount is calculated from the interval between the marks detected by the mark detection means, and the rope extension amount under a constant tension is calculated based on the rope tension detected by the tension detection means. And an arithmetic means for correcting the elongation amount and performing strength management based on the corrected elongation amount.

FIG. 1 is a diagram illustrating a schematic configuration of a machine roomless type elevator according to the first embodiment. FIG. 2 is a cross-sectional view showing the structure of the main rope used for the elevator in the 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 according to 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 a pair of mark detection sensors in the same embodiment are provided on both sides of the main rope. FIG. 7 is a flowchart for explaining the operation of the rope inspection system according to the embodiment. 8A and 8B are diagrams for explaining the relationship between the pulse signal and the mark interval in the embodiment. FIG. 8A is a pulse signal output in synchronization with the movement of the main rope, and FIG. 8B is an installation. The mark interval at the time, (c) in the figure is the mark interval when the rope is stretched due to secular change. FIG. 9 is a diagram showing the relationship between the reflected light intensity obtained from the mark detection sensor and the frequency in the second embodiment. FIG. 10 is a diagram showing the relationship between the elongation rate and the residual strength due to the deterioration of the rope. FIG. 11 is a diagram showing the result of simulating the change in rope tension with respect to the car position. FIG. 12 is a diagram for explaining the shift of the elongation rate determination criterion in consideration of variations in rope tension.

  First, before carrying out 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.

  For example, in a wire rope used for an elevator main rope or the like, a strand and a cord which are tensile strength members are squeezed by tension and rubbed 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 disconnection of the strands in the vicinity of the heart rope (the portion surrounded by the dotted line in FIG. 2). Due to the deterioration of this portion, the strand moves in the direction of the heart rope (the direction in which the rope diameter decreases), so that the wire rope structure is stretched.

  As a result of verifying the wire rope having such a structure, it has been found that there is a correlation as shown in FIG. 10 between the elongation and the strength. In FIG. 10, the horizontal axis represents the elongation percentage of the rope. For the sake of confidentiality, although specific numerical values are omitted, λ in the figure is about several percent and the distance is about several mm. The vertical axis represents the strength factor of the rope (this is called the residual strength factor). When the rope gradually grows due to aging from the new state at the time of installation, the strength also decreases. Usually, the strength rate is set to 80% as the reference strength, and safety is obtained by setting the time when the rope elongation rate becomes λ as the replacement time.

  However, the elongation of the rope due to aging includes elastic elongation in addition to the decrease in the radial direction of the spiral due to wear of the strands and cords. The characteristics of the elongation rate and strength factor of the rope shown in FIG. 10 are obtained by a bending durability test under a constant tension. When the tension is removed, the structural elongation associated with the decrease in the spiral radius remains, but a gap is generated in each part of the strands, strands, and the like due to the elastic restoration of the structural shape, so a stable amount of elongation cannot be obtained.

  In the maintenance inspection, it is desirable to measure the amount of elongation under the same tension as in the durability test as in the characteristics of FIG. 10, but it is difficult to apply a constant tension to each of the multiple-line ropes constituting the rope. . This is because, in an elevator system using a plurality of ropes, a certain level of tension variation is unavoidable. As a result, there is a difference in the elastic elongation of each rope, and the amount of each rope sent by the sheave varies depending on the tension. As a result, the tension state of each rope as the elevator (cage) moves up and down. Changes.

  FIG. 11 shows the result of simulating the change in tension of the five ropes relative to the car position. As a condition, ± 2.5% and ± 5% of the average tension are set for other ropes with respect to the No3 rope under the average tension on the lowest floor in the 20m stroke.

  With the exception of No. 3 rope under average tension, the tension of each rope changes in a closed loop as the elevator moves up and down, and the vertical relationship is reversed between when it is on the lowest floor and when it is moved to the top floor. ing. Further, the variation width of the tension becomes large especially when the terminal moves to the final floor (the top floor in FIG. 11), and exceeds the initial ± 5%.

  The variation width (variation width) of the tension depends on the variation width after tension adjustment, which is the initial setting, the lifting stroke, the sheave groove radius, the variation in the rope diameter, and the like. The closed loop curve showing the tension change of each rope is generally constant if the loading state does not change, but changes when the loading state changes, and converges to a constant curve as the same loading state continues.

  In an elevator system having a tension change resulting from variations after tension adjustment, sheave diameter, and rope diameter, there has never been a method for performing maintenance and inspection based on the elongation-residual strength characteristics shown in FIG.

  In Patent Document 1 described as a prior document, the tension state of the belt is measured by measuring the torque of the hoisting machine, and the tension state is grasped with respect to the change in the tension of the belt due to the change in the position of the car and the change in the load. A method for correcting the amount of elongation of the film 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, it is not possible to correct the amount of elongation with respect to the change in tension caused by this.

  In order to perform the strength management with the exchange standard elongation obtained by the elongation rate-residual strength characteristics, it is assumed that there is no appropriate elongation amount correction, and at the time of inspection in anticipation of safety, as shown in FIG. It is necessary to apply an elongation λ ′ that takes into account the elastic elongation δλ. For this reason, even when the rope strength is equal to or higher than the reference value, the rope 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 diagram illustrating a schematic configuration of a machine roomless type elevator according to the first embodiment.

  The elevator 1 has a hoistway 2 provided in a building, and a car 11 and a counterweight 12 are supported inside the hoistway 2 so as to be movable up and down via guide rails. Further, a hoisting machine 14 having a traction sheave 13 is installed in the upper part 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 intermediate portion 3c of the main rope 10 is continuously wound around a sheave 15 provided on the car 11, a traction sheave 13 provided on the hoisting machine 14, and a 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 driving the hoisting machine 14, the car 11 and the counterweight 12 are lifted and lowered in the hoistway 2 through the main rope 10 in accordance with the rotation of the traction sheave 13.

  Further, a speed governor (governor) 17 is provided in the hoistway 2. In the figure, 18 is a governor rope for rotationally driving the governor 17. The governor 17 detects the position and speed of the car 11 via a governor rope 18 that moves as the car 11 moves up and down, and brakes when the speed of the car 11 exceeds the set speed due to some abnormality. Start up.

  In a machine room-less type elevator without a 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 2: 1 roping as shown in FIG. 1, but may be other methods such as 1: 1 roping.

  Here, the rope inspection system of the present embodiment includes a mark detection sensor 21, an encoder 22, a calculation device 23, a display device 24, and a 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 in the speed governor 17. The encoder 22 generates a pulse signal in synchronization with the movement of the main rope 10 as the car 11 moves up and down.

  The arithmetic unit 23 counts the pulse signal generated from the encoder 22 between each mark 20 detected by the mark detection sensor 21 at the time of inspection, and calculates the extension amount of the main rope 10 from the count value. Further, in the present embodiment, the calculation device 23 uses the tension detected by the tension detection device 40 and the elastic modulus of the main rope 10 to calculate the calculated extension amount of the main rope 10 under the constant tension. The strength is managed based on the amount of elongation after the correction. The display device 24 displays the amount of extension (distance between marks) of the main rope 10 obtained by the arithmetic device 23. Note that the arithmetic device 23 and the display device 24 are general-purpose computers.

  The tension detection device 40 is provided at the end of the main rope 10 and detects the tension of the main rope 10 using a load cell having a strain gauge or the like inside. In the example of FIG. 1, the tension detecting device 40 is provided at one end 3 a of the main rope 10 on the car 11 side, but the tension detecting device 40 is provided on the other end 3 b 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 includes a rope main body 31 as a tensile member and an outer covering layer 32 that entirely covers 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 with the core rope 30 as the center. The outer coating layer 32 is formed of a thermoplastic resin material having wear resistance and a high friction coefficient, such as polyurethane. The outer covering layer 32 has an outer peripheral 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 comes into contact with friction when it is wound around each sheave 13, 15, 16.

  Further, the resin material forming the outer covering layer 32 is filled in the gaps between the adjacent strands 33. Therefore, the outer covering layer 32 has a plurality of filling portions 34 that enter between the strands 33 adjacent 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 coating 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 elongation due to 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 of these marks 20 is formed by a continuous straight line or an intermittent dotted line in the circumferential direction of the main rope 10.

  By the way, as for the main rope 10, the clearance gap between the strands 33 and the clearance gap between the some strands which comprise the strand 33 reduce with progress of a use period. As a result, the strands 33 and the strands repeat friction with each other, and the wear and breakage of the strands 33 and the strands proceed.

  In particular, the portions where the main rope 10 comes into contact with the sheaves 13, 15, 16 are repeatedly subjected to friction. For this reason, the progress degree of wear and disconnection 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, 16, thereby reducing the rope diameter of the main rope 10, Local growth occurs. Therefore, the strength of the main rope 10 can be managed by clarifying the relationship 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 maximum.

  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 moved up and down between the uppermost floor and the lowermost floor in the inspection operation, most of the entire length of the rope 10 passes through the mark detection sensor 21 except for the portions close to the rope hitches 4a and 4b. The marks 20 can be detected continuously during the passage. In addition, 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, and counts the number of pulse signals output from the encoder 22 during that time, thereby extending the distance between the marks from the count value. Calculate as a quantity.

  The position in the vicinity of the hoisting machine 14 that fixes the mark detection sensor 21 may be on the car 11 side or on the counterweight 12 side. On the counterweight 12 side, since the rope tension does not depend on the loading state of the car 11, the replacement determination threshold value is constant for a specific structure, which is highly convenient for operation. This is because the elastic elongation of the main rope 10 differs due to the difference in mass between the car 11 and the counterweight 12, and shows different elongation amounts for a certain deterioration. However, since the threshold value for replacement determination may be changed according to the rope tension, this is not an essential problem in the measurement of the mark interval.

  The mark detection sensor 21 is preferably composed of a photoelectric sensor using laser reflected light in view of responsiveness. In a commercially available photoelectric sensor, a sensor that irradiates an object with laser light and detects a change in the color of the surface by a difference in reflected light intensity has recently become widespread.

  4 and 5 are diagrams showing a basic configuration when the mark 20 on the main rope 10 is optically detected by the mark detection sensor 21. 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 from obliquely behind. Here, a configuration in which one mark detection sensor 21 is arranged on one side of the main rope 10 is shown. However, in consideration of a 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. The mark detection sensor 21 is preferably arranged.

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

  If the operation speed of the main rope 10 is 1 m / s or less, sufficient response performance can be obtained, and the cost is lower than the detection method using the image processing camera as in the prior art document 1. Furthermore, in the detection method using the image processing camera, the mark interval cannot be measured from the captured image unless the camera is installed at a location away from the main rope 10 and the main rope 10 is photographed over a wide range. On the other hand, in this embodiment, since the mark detection sensor 21 should just be installed near the main rope 10, there exists an advantage which does not require the environment of a rope inspection widely.

  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 state that affect the laser reflected light intensity change over time.

  For example, when a part of the mark 20 is lost, the reflected light intensity decreases, so that it is necessary to increase the detection sensitivity. Further, when an adhering matter (light color) that easily reflects light is fixed on the rope surface, it is necessary to lower the detection sensitivity. Since the state of the rope surface varies depending on the use conditions of the elevator, by making it possible to adjust the determination threshold according to the state for each property, it is possible to prevent erroneous detection and omission of detection of the mark 20.

  The mark 20 provided on the surface of the main rope 10 has been described as having a high reflected light intensity. However, in summary, the portion of the main rope 10 where the mark 20 is applied (mark portion) and the mark 20 are applied. It is sufficient that there is a difference in reflected light intensity between the non-marked part (non-marked part), and the function is the same even if the reflected light intensity is reduced at the marked part.

  Further, in order to reliably detect the mark 20 that the main rope 10 has a rotation property and a part of which is lost over time, it is necessary to have a detection sensitivity for the entire circumference of the rope. Therefore, it is preferable to provide a pair of mark detection sensors 21 so as to be sandwiched from both sides of the main rope 10 as shown in FIG.

  In this case, in order to suppress an increase in the number of sensors, the irradiation range in the diameter direction of the main rope 10 of the laser beam and the horizontal light receiving range of the reflected light included in one mark detection sensor 21 are shown in FIG. As shown, a configuration that substantially matches the diameter B of the main rope 10 is desirable. This is because, in order to prevent detection of the mark 20 from being detected, it is necessary to have sensitivity to the rope width as a minimum. However, if the width is wider than the rope width, reflection from the structure behind the main rope 10 or the like. This is because the possibility of false detection increases.

  Next, the operation of this system will be described.

  FIG. 7 is a flowchart for explaining the operation of the present system, and shows a process for automatically measuring the interval between the marks 20 by the inspection operation and determining the deterioration state of the main rope 10.

  First, the car 11 is moved to the lowest floor, and inspection operation is started from there to the highest 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 suspending the car 11 and the counterweight 12 moves slowly 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. The arithmetic unit 23 sequentially counts the number of pulse signals output from the encoder 22 (step S12).

  Further, as the main rope 10 moves, the mark 20 provided on the surface of the main rope 10 is optically detected by the mark detection sensor 21. The arithmetic unit 23 confirms the count value of the current pulse signal at the timing when the mark 20 is detected by the 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 20 is detected by the mark detection sensor 21, and the count value and the amount of rope movement (pulse rate) per pulse. The distance between marks is calculated 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 extended, 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 deterioration, the calculated distance between the marks becomes larger than the mark interval at the time of installation.

  Thereafter, 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 to S15).

  As a pulse signal counting method, 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 every time a mark is detected. In the former method, a difference value between the integrated value of the pulse when the mark 20 is detected and the integrated value of the pulse when the mark 20 is detected last time is obtained, and the distance between the marks is obtained from the difference value. Become.

  In order to associate the rope position and 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 accumulated values of the pulses when the mark 20 is detected are sequentially stored, and the car 11 is moved later using the accumulated value as an index, the portion of the main rope 10 to be checked is marked. It can be visually observed at the place where the detection sensor 21 is installed.

  For example, in the case of 2: 1 roping, the car movement amount obtained by the encoder 22 provided in the governor 17 is ½ of the rope movement amount. Therefore, in order to obtain the mark interval from the count value of the pulse signal, it is necessary to consider the roping ratio at that time.

  Here, when the elevator is installed, 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 is 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 extended due to 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 is shown in FIG.

  FIG. 8 is a diagram for explaining the relationship between the pulse signal and the mark interval. FIG. 8A is a pulse signal output in synchronization with the movement of the main rope 10, and FIG. 8B is a mark interval at the time of installation. FIG. 5C shows the mark interval when the rope is stretched due to secular change.

  Assuming that the reference value when the pulse signal is counted at the mark interval at the time of installation is n pulses, the count value obtained by the inspection operation is slightly different from the n pulse at the time of installation if the main rope 10 is not deteriorated. Are substantially the same. However, when the main rope 10 is extended due to deterioration, the count value obtained by 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 extension amount 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, the rope elongation at the time of inspection includes elastic elongation due to tension in addition to elongation due to aging. Therefore, the calculation device 23 corrects the elongation amount calculated in step S16 to the elongation amount under a constant tension in consideration of the elastic elongation due to the tension (step S17).

More 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)
As required.

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

  Here, the main rope 10 is elastically stretched according to the tension T when the main rope 10 passes the mark detection sensor 21. For this reason, 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)
However, k = AE / D0
k is the spring constant (elastic modulus) of the rope with respect to the mark interval D0 when there is no load. A is the cross-sectional area of the rope, and E is the elastic modulus of the rope.

  By using the above equation (2), the elongation Λ at the standard tension T0 can be obtained from the following equation, regardless of the tension state of the rope to be inspected.

Λ = d / D0 (3)
Λ is the elongation rate under a constant tension as in the bending durability test. The amount of elastic elongation included in the amount of elongation of the rope can be regarded as equivalent to a deteriorated sample that determines the exchange standard, and therefore can be managed by the elongation rate λ in the elongation-residual strength characteristics shown in FIG. That is, it is possible to use the main rope 10 having strength and safety for a longer time than in the case where λ ′ is managed as an exchange standard in view of the tension variation shown in FIG.

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

  When it is determined that the main rope 10 is in a deteriorated state, the arithmetic unit 23 displays a warning message on the display device 24 or generates an alarm sound, for example, to notify the maintenance staff that the rope replacement time is approaching. Inform. Thereby, the inspection work by the maintenance staff can be reduced, and the time when the rope needs to be replaced can be grasped and dealt with.

  Further, since it is easy to correlate the measured value of the mark interval of each part from the count value of the pulse signal and the amount of rope movement by the inspection operation, the rope position at the location exceeding the threshold value is displayed on the display device 24. May be. A portion where the mark interval exceeds the threshold is a portion where 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 work is facilitated by displaying the rope position at the location exceeding the threshold.

  Alternatively, the most extended portion of the main rope 10, that is, the rope position with the maximum mark interval may be displayed on the display device 24. In general, a portion where the main rope 10 is largely deteriorated is a portion where the bending load associated with the floor where the stoppage frequency of the car 11 is high is maximized. However, for example, if there is a part that is accidentally damaged during installation or the like, there is a possibility that deterioration of the damaged part will precede. By displaying the rope position of the maximum stretched portion, it becomes easy to check such a deteriorated portion different from the normal deterioration.

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

  Furthermore, if the history information is periodically sent to a remote elevator monitoring center (not shown), the elevator monitoring center can centrally manage the deterioration state of the main rope 10 of each property, and the rope replacement time The maintenance staff can be informed of nearby properties.

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

(Second Embodiment)
Next, the second embodiment will be described. It is desirable in terms of accuracy to use a load cell having 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 with reference to FIGS. 4 and 5, a photoelectric sensor is used as the mark detection sensor 21. As a general photoelectric sensor detection method, a method of irradiating an object with visible light or infrared light and detecting a change in surface due to a mark or the like based on a difference in reflected light intensity is widespread.

  In the mark detection method using the photoelectric sensor having such a configuration, when the main rope 10 is swayed, the reflected light intensity varies. 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 regular intervals as shown in FIG. 9 is obtained.

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

ν = n / (2L) × √ (T / ρ) (n = 1, 2, 3,...) (4)
L is the length of the string, T is the tension, and ρ is the rope line 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 is obtained by counting the pulse signals of the encoder 22. The value of ρ is known.

  It is easy to vibrate the main rope 10 at an arbitrary 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 frequency of the main rope 10, the tension T of the main rope 10 can be obtained from the above equation (4). A series of these processes is executed by the arithmetic unit 23.

  In addition, the dispersion | variation in the tension | tensile_strength of each rope which comprises the main rope 10 of an elevator arises with the difference in the feed amount of a rope. When attention is paid to a specific rope, the range of change increases as the moving distance of the car 11 increases. In the case of the car side rope, generally, when the car 11 moves to the top floor, the variation width of the tension of each rope becomes the maximum. In addition, the tension change increases near the top floor because the difference in the rope feed amount is stored on the shortened rope. Therefore, it is effective to reduce the spring constants of the rope hitches 4a and 4b (see FIG. 1) in order to suppress the tension change width. This is considered to be the same effect as extending a rope that has become shorter on the top floor.

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

  Thus, according to the second embodiment, the rope tension corresponding to the car position can be obtained even by using the mark detection sensor as a tension sensor. Thereby, similarly to the first embodiment, it is possible to perform strength management by correcting the amount of elongation of the rope in consideration of elastic elongation due to tension.

  According to at least one of the embodiments described above, in the maintenance and inspection of the rope where the tensile strength material cannot be visually observed, the operational life in the state where the rope strength is secured is improved and the reliability of the strength management is improved. An elevator rope inspection system can be provided.

  In the example of FIG. 1, the pulse signal output from the encoder 22 provided in the governor 17 is counted. However, for example, a similar encoder is provided in the traction sheave 13 and the pulse output from the encoder is provided. It may be configured to count signals. Moreover, it is good also as a structure which fixes an encoder to the upper part of the passenger car 11, and press-contacts the rotation part of the encoder to a guide rail. These are rotary encoders, but for example, a linear encoder (not shown) that outputs a pulse magnetically or optically along the ascending / descending direction of the car 11 in the hoistway 2 may be used.

  In short, several embodiments of the present invention have been described, but 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, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

  DESCRIPTION OF SYMBOLS 1 ... Elevator, 2 ... Hoistway, 3a ... Rope one end part, 3b ... Rope other end part, 3c ... Rope middle part, 4a, 4b ... Rope hitch, 5 ... Guide rail, 10 ... Main rope, 11 ... Ride car, DESCRIPTION OF SYMBOLS 12 ... Counterweight, 13 ... Traction sheave, 14 ... Hoisting machine, 15, 16 ... Sheave, 17 ... Speed governor, 18 ... Governor rope, 20 ... Mark, 21 ... Mark detection sensor, 22 ... Encoder, 23 ... Arithmetic unit 23a ... Memory, 24 ... Display device, 25 ... Irradiation unit, 26 ... Light receiving unit, 30 ... Heart rope, 31 ... Rope body, 32 ... Outer coating layer, 32a ... Outer peripheral surface, 33 ... Strand, 34 ... Filling unit, 40: Tension detector.

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 detecting means for detecting the tension of the rope;
The rope extension amount is calculated from the interval between the marks detected by the mark detection means, and the rope extension amount under a constant tension is calculated based on the rope tension detected by the tension detection means. An elevator rope inspection system comprising: an arithmetic unit that corrects the amount of elongation and performs strength management based on the amount of elongation after the correction. The mark detection means is
It consists of an optical sensor that irradiates the resin-coated surface of the rope with a laser beam and optically detects the presence or absence of each mark by the intensity of the reflected light, and has a detection sensitivity with respect to the width of the rope diameter. The elevator rope inspection system according to claim 1. The optical sensor is
3. 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 moves the car up and down. The elevator rope inspection system according to claim 1, wherein the tension detecting means detects the tension of the rope using a load cell provided at an end of the rope. The tension detecting means is
3. The elevator rope according to claim 2, wherein the roll vibration of the rope is obtained from the intensity of the reflected light obtained from the optical sensor, and the tension of the rope acting on the roll vibration is detected. Inspection system. 2. The elevator rope inspection system according to claim 1, wherein the tension detecting means detects the tension of the rope after the elevator car has been lifted and lowered a plurality of times in accordance with a predetermined condition. Comprising pulse generating means for generating a pulse signal in synchronization with the movement of the rope;
The computing means is
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 rope extension is calculated using the count value and the amount of rope movement per pulse. The elevator rope inspection system according to claim 1.

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