Tension measuring device and tension measuring method

Abstract

To measure a partial change in tension in a wire rope.SOLUTION: A tension diagnosis device 10 according to one embodiment of the present invention includes: a magnetic sensor 12 for acquiring information corresponding to a strand width, which is the distance between recesses along the longitudinal direction of one strand in a specific section of a wire rope; and a signal analysis unit 3 for calculating a strand frequency indicating the period of temporal variation in the information corresponding to the strand width acquired by the magnetic sensor 12, and for measuring the tension of the wire rope at a portion where the information corresponding to the strand width is acquired, on the basis of information of the strand frequency.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a tension measuring device and a tension measuring method. [Background technology]

[0002] Wire ropes are widely used in machinery such as elevators and cranes, as well as in structures such as bridges. In elevators, which are elevators, wire ropes are used as the main ropes, and multiple main ropes are used to raise and lower the car. Elevator wire ropes are subject to deterioration such as bending fatigue, wear, and corrosion over time, so they require regular inspections and testing.

[0003] The wire rope, powered by a hoist, travels through the rope groove of the sheave while carrying the load of the car and counterweight. At this time, friction occurs between the rope groove and the wire rope due to the load and tension on the wire rope. Because elevators use multiple wire ropes, it is necessary to ensure that the tension on each rope is uniform. For example, if the tension on each of the multiple main ropes is uneven, the load on the main rope with the highest tension increases, which can cause the main rope to deteriorate earlier than when the tension is lower. Therefore, monitoring the tension state of the wire rope is used as an auxiliary method for diagnosing main rope deterioration.

[0004] A conventional technique for measuring tension in a wire rope is, for example, the tension measuring device described in Patent Document 1. The tension measuring device disclosed in Patent Document 1 strikes each of three wire ropes with a hammer, acquires the frequency of vibrations generated in the wire ropes using an acceleration sensor, and indirectly determines the tension of the wire rope based on the acquired frequency. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 7-209109 Summary of the Invention [Problem to be solved by the invention]

[0006] When an elevator car is moving, bending of the sheave and changes in load cause the wire rope serving as the main rope to expand and contract in parts like a spring. Accumulating such expansion and contraction of the wire rope affects the degree of deterioration of the wire rope. Meanwhile, the tension measuring device described in Patent Document 1 is a technology that measures the wire rope in a static state when the car is not moving, so it is considered difficult to capture the spring-like expansion and contraction that occurs in parts of the wire rope and measure the tension.

[0007] The present invention has been made in consideration of the above circumstances, and an object of the present invention is to make it possible to measure changes in partial tension in a wire rope. [Means for solving the problem]

[0008] A tension measuring device according to one aspect of the present invention measures the tension of a wire rope formed by twisting multiple strands. The tension measuring device according to one aspect of the present invention includes a sensor unit that acquires information corresponding to a strand width, which is the distance between recesses in the longitudinal direction of one strand, in a specific section of the wire rope, and a tension measuring unit that calculates a strand frequency that indicates the period of change in the information corresponding to the strand width acquired by the sensor unit over time, and measures the tension of the wire rope in the portion where the information corresponding to the strand width was acquired based on the information of the strand frequency. [Effects of the Invention]

[0009] According to at least one aspect of the present invention, changes in local tension in a wire rope are measured. Problems, configurations, and effects other than those described above will become apparent from the following description of the embodiments. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a diagram showing an example of the configuration of a wire rope according to an embodiment of the present invention. FIG. [Figure 2] 1 is a diagram showing an example of the configuration of a magnetizer used to detect leakage magnetic field according to an embodiment of the present invention; [Figure 3] 1 is a schematic diagram showing an example of the configuration of an elevator according to an embodiment of the present invention. [Figure 4] 1 is a block diagram showing an example of the configuration of a tension diagnostic system according to an embodiment of the present invention. [Figure 5] FIG. 1 illustrates an example of a wire rope and strand signal according to an embodiment of the present invention. [Figure 6] 1 is a graph showing the relationship between the elongation of a wire rope according to one embodiment of the present invention and the load applied to the wire rope. [Figure 7] 1 is a graph showing an example of a change in strand frequency when the load applied to the wire rope according to one embodiment of the present invention is changed. [Figure 8] 1 is a flowchart showing an example of a procedure for diagnosing tension of a wire rope by a tension diagnosis system according to Example 1 of an embodiment of the present invention. [Figure 9] 10 is a flowchart showing an example of a procedure for diagnosing the tension of a wire rope by a tension diagnosis system according to Example 2 of an embodiment of the present invention. [Figure 10] FIG. 10 is a diagram showing an example of the configuration of an analysis result display screen according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, examples of modes for carrying out the present invention (hereinafter referred to as "embodiments") will be described with reference to the accompanying drawings. The present invention is not limited to the embodiments, and various numerical values ​​in the embodiments are merely examples. Furthermore, in this specification and drawings, identical components or components having substantially the same functions will be designated by the same reference numerals, and redundant explanations will be omitted.

[0012] <Wire rope configuration> First, the configuration of a wire rope 30, which is the target of tension diagnosis by a tension diagnosis system 100 (see FIG. 4) according to this embodiment, will be described with reference to Fig. 1. Fig. 1 is a diagram showing an example of the configuration of the wire rope 30. The wire rope 30 is a rope used as a main rope in an elevator 50 (see Fig. 3).

[0013] As shown in FIG. 1, the wire rope 30 is formed by twisting eight strands 310 together, and the strand 310 is made up of a large number of wires 311. If any of the wires 311 has a break, the tension diagnostic system 100 is required to reliably detect it. The break in the wire 311 varies depending on the location; if it occurs on the outer periphery of the strand 310, it is called a mountain break 311a in the wire 311, and if it occurs midway between adjacent strands 310, it is called a valley break 311b in the wire 311. The valley break 311b is a break in the wire 311 midway between the outermost and innermost portions of the strand 310 in the circumferential direction of the strand 310. The number of strands 310 constituting the wire rope 30 is not limited to the example (eight) shown in FIG. 1.

[0014] Because the wires 311 of the wire rope 30 are made of a magnetic metal material, deterioration such as broken wires in the wire rope 30 can be detected using magnetic leakage flux testing. Magnetic leakage flux testing is a method in which the wire rope 30 is excited by a magnet or the like, and the leakage magnetic flux generated from the wire rope 30 by the excitation is detected by a magnetic sensor 12 (see FIG. 2). The tension diagnosis system 100 (see FIG. 2) according to this embodiment diagnoses deterioration of the wire rope 30 by measuring the tension of the wire rope 30 using magnetic leakage flux testing.

[0015] <Magnetizer configuration> Fig. 2 is a diagram showing an example of the configuration of the magnetizer 1 used to detect leakage magnetism from the wire rope 30. As shown in Fig. 2, the magnetizer 1 has two magnets 11-1 and 11-2 arranged with opposite polarities. When the magnetizer 1 approaches the wire rope 30, the magnetic field causes magnetic flux to circulate between the wire rope 30 and the magnetizer 1, forming a magnetic path in a predetermined section in the longitudinal direction of the wire rope 30.

[0016] The magnetizer 1 also includes a magnetic sensor 12 (an example of a sensor unit), which is disposed along the outer periphery of the wire rope 30. The magnetic sensor 12 is configured, for example, with a detection coil and a Hall element (neither of which are shown). Note that the magnetic sensor 12 may also be, for example, a TMR (Tunnel Magneto Resistive) sensor, an AMR (Anisotropic Magneto Resistive) sensor, or a GMR (Giant Magneto Resistive effect) sensor. The magnetic sensor 12 included in the magnetizer 1 is disposed at a position that is considered optimal depending on the type of magnetic sensor 12, etc.

[0017] In the wire rope 30 in which a magnetic path is formed, the magnetic sensor 12 detects periodic magnetic signals originating from the strands. Because the wire rope 30 has a structure in which strands 310 are twisted, there are irregularities on its surface, and the distance between the positions of the irregularities and the magnetic sensor 12 varies. Therefore, changes in magnetic flux occur constantly. Specifically, the magnetic signals increase at the convex portions (peaks) of the strands 310 because they are close to the magnetic sensor 12, and the magnetic signals decrease at the concave portions (valleys) of the strands 310 because they are farther away from the magnetic sensor 12.

[0018] When operating car 51 (see FIG. 3) of elevator 50, wire rope 30 is reeled out by hoist 53, causing counterweight 53 and car 51 (both see FIG. 3) to rise and fall within the elevator. At this time, magnetic sensor 12 attached to wire rope 30 detects a magnetic signal that repeatedly increases and decreases in response to the unevenness of strand 310. The magnetic signal that repeatedly increases and decreases exhibits a sine wave, and is acquired as a strand signal that changes periodically depending on the configuration of wire rope 30 and the reeling speed of hoist 53.

[0019] For example, if the tension applied to one wire rope 30 is constant over its entire length, the period of the strand signal will be a constant value. On the other hand, if the tension of the wire rope 30 changes due to the influence of a load or the like, causing even slight stretching of the rope in some areas, the period of the strand signal will not be uniform over its entire length.

[0020] The tension diagnostic system 100 according to this embodiment detects periodic changes in the strand signal as dynamic changes in the tension of the wire rope 30, thereby determining the deterioration tendency of the wire rope 30 due to loads or the like.

[0021] <Elevator configuration> Next, the configuration of an elevator 50 that uses the wire rope 30 will be described with reference to Fig. 3. Fig. 3 is a schematic diagram showing an example of the configuration of the elevator 50.

[0022] As shown in Fig. 3, the elevator 50 includes a car 51 for transporting passengers P and the like, a counterweight 52, a hoist 53, a deflector sheave 54, and a wire rope 30 serving as the main rope. The car 51 and the counterweight 52 are disposed in a hoistway (not shown) provided within a building. The hoist 53, the deflector sheave 54, and an elevator control device (not shown) are installed in a machine room (not shown) provided above the hoistway. The deflector sheave 54 is disposed near the hoist 53.

[0023] A wire rope 30 serving as a main rope is wound around a hoist 53 and a deflector sheave 54. One end of the wire rope 30 is connected to the top of the cage 51, and the other end is connected to the top of the counterweight 52. The hoist 53 raises and lowers the cage 51 and the counterweight 52 via the wire rope 30.

[0024] <Configuration of tension diagnostic system> Next, the configuration of the tension diagnostic system 100 according to this embodiment will be described with reference to Fig. 4. Fig. 4 is a block diagram showing an example of the configuration of the tension diagnostic system 100. As shown in FIG. 4, the tension diagnostic system 100 includes a tension diagnostic device 10 and a terminal device 20.

[0025] [Configuration of tension diagnostic device] The tension diagnostic device 10 (an example of a tension measuring device) is a device that diagnoses the tension of each wire rope 30 (see Figure 1) used as a main rope in an elevator 50, and is equipped with a magnetizer 1, a magnetic sensor circuit 2, and a signal analysis unit 3.

[0026] Magnetizer 1 includes magnets 11-1 to 11-m (m is a natural number of 2 or more) and magnetic sensors 12-1 to 12-n (n is a natural number of 2 or more). Magnetizer 1 has already been described with reference to FIG. 1, so a duplicated description will be omitted.

[0027] The magnetic sensor circuit 2 is made up of magnetic sensor circuits 2-1 to 2-n. The magnetic sensor circuit 2 has magnetic signal amplifiers 21-1 to 21-n and filter circuits 22-1 to 22-n. In the following description, when it is not necessary to distinguish between the magnetic signal amplifiers 21-1 to 21-n, they will be collectively referred to as "magnetic signal amplifier 21," and when it is not necessary to distinguish between the filter circuits 22-1 to 22-n, they will be collectively referred to as "filter circuit 22."

[0028] The magnetic signal amplifier 21 amplifies the magnetic signal detected by the magnetic sensor 12. The filter circuit 22 performs general analog filtering on the magnetic signal amplified by the magnetic signal amplifier 21 to generate an analog signal, and outputs the generated analog signal to the filter circuit 22. In the analog filtering, the filter circuit 22 removes commercial frequencies and noise components, etc., and passes only the desired frequency range. The analog magnetic signal consisting only of the desired frequency range is output to the signal analysis unit 3.

[0029] The signal analysis unit 3 (an example of a tension measurement unit) is made up of A / D converters 31-1 to 31-n, signal collectors 32-1 to 32-n, and a signal processor 33. In the following description, when it is not necessary to distinguish between the A / D converters 31-1 to 31-n, they will be collectively referred to as "A / D converter 31," and when it is not necessary to distinguish between the signal collectors 32-1 to 32-n, they will be collectively referred to as "signal collector 32."

[0030] The A / D converter 31 converts the analog magnetic signal output from the magnetic sensor circuit 2 into a digital signal, and outputs the digital magnetic signal to the signal collector 32.

[0031] The signal processor 33 has the functions of signal addition and digital filtering, and generates a strand signal by performing signal processing on the digital magnetic signal extracted from the signal collector 32. Furthermore, the signal processor 33 measures and determines the tension of the wire rope 30 based on the frequency of the strand signal, and determines whether a wire has been broken. The signal processor 33 can determine the tension by determining whether the frequency of the strand signal of the wire rope 30 is within a reference value range. The reference value is a value that serves as a criterion for determining deterioration of the wire rope 30, and is set in advance for each type of wire rope 30 and each model of elevator.

[0032] The signal processor 33 is configured, for example, by a one-chip microcomputer (microcontroller) or a single-board computer, and includes a CPU (Central Processing Unit) 331a, a ROM (Read Only Memory) 331b, and a RAM (Random Access Memory) 331c. The CPU 331a reads program code of software that realizes each function according to this embodiment from the ROM 331b, loads it into the RAM 331c, and executes it. Note that the control unit 331 may include a processing device such as an MPU (Micro-Processing Unit) instead of the CPU 331a. Alternatively, the control unit 331 may include both the CPU 331a and the MPU.

[0033] The RAM 331c temporarily stores variables, parameters, etc. generated during the calculation process by the CPU 331a. The ROM 331b stores software programs, etc., that realize the functions according to this embodiment.

[0034] The nonvolatile storage 331d is a storage unit configured, for example, with an HDD (Hard Disk Drive), an SSD (Solid State Drive), etc. In addition to an OS (Operating System) and various parameters, the nonvolatile storage 331d also stores programs for operating the tension diagnostic device 10. Note that software programs for realizing the various functions according to this embodiment may be stored in the nonvolatile storage 331d.

[0035] The program is stored in the form of a computer-readable program code, and the CPU 331a sequentially executes operations in accordance with the program code. In other words, the ROM 331b or the non-volatile storage 331d is used as an example of a computer-readable non-transitory recording medium that stores a program to be executed by a computer.

[0036] [Terminal device configuration] The terminal device 20 is configured, for example, by a general-purpose computer or the like, and includes a power supply 201, a control unit 202, a non-volatile storage 203, a communication I / F (Interface) 204, and a data input / display unit 205. These components constituting the terminal device 20 are connected to each other via a bus B so as to be able to communicate with each other.

[0037] The power supply 201 supplies power to each component of the terminal device 20. The control unit 202 is a functional block that controls the operations of the magnetizer 1, the signal analysis unit 3, etc., and includes a CPU 202a, a ROM 202b, and a RAM 202c.

[0038] The CPU 202a reads out the program code of the software that realizes each function according to this embodiment from the ROM 202b, expands it into the RAM 202c, and executes it. Note that the control unit 202 may include a processing device such as an MPU instead of the CPU 202a. Alternatively, the control unit 202 may include both the CPU 202a and the MPU.

[0039] Variables, parameters, etc. generated during the arithmetic processing by the CPU 202a are temporarily written to the RAM 202c. The ROM 202b stores software programs, etc., that realize the various functions according to this embodiment.

[0040] The nonvolatile storage 203 is a storage unit configured, for example, with an HDD, an SSD, etc. In addition to the OS and various parameters, the nonvolatile storage 203 also stores programs for operating the terminal device 20. Note that software programs for realizing the functions according to this embodiment may be stored in the nonvolatile storage 203.

[0041] The program is stored in the form of a computer-readable program code, and the CPU 202a sequentially executes operations in accordance with the program code. In other words, the ROM 202b or the non-volatile storage 203 is used as an example of a computer-readable non-transitory recording medium that stores a program to be executed by a computer.

[0042] The communication I / F 204 is configured by a communication device or the like that controls communication between other devices (not shown). Networks for which the communication I / F 204 performs communication control include, for example, multi-drop serial communication such as RS-485 and communication paths that provide multiple topologies such as Ethernet (registered trademark). Communication paths that provide multiple topologies include wired communication paths such as LAN (Local Area Network) and WAN (Wide Area Network), and wireless communication paths such as RAN (Radio Area Network). Networks for which the communication I / F 204 performs communication control also include wireless paths such as Wi-Fi (registered trademark) and wireless paths provided by wireless communication infrastructure.

[0043] The data input / display unit 205 is composed of an input unit that accepts instruction input from a user (not shown) and a display unit that displays an analysis result display screen 40 (see FIG. 10) and the like. The analysis result display screen 40 is a screen that displays the analysis results obtained by the signal analysis unit 3. The input unit is composed of, for example, a mouse, a keyboard, and the like, and the display unit is composed of an LED (Liquid Crystal Display), and the like. The input unit and the display unit may be integrally formed as a touch panel.

[0044] <Outline of tension measurement process> Next, an outline of the tension measurement process of the wire rope 30 by the tension diagnostic system 100 according to this embodiment will be described with reference to FIGS. 5 is a diagram showing an example of the wire rope 30 and the strand signal Ss. The leakage magnetic flux from the strand 310 of the wire rope 30 is detected by the magnetic sensor 12 (see FIG. 4) and is converted into the strand signal Ss by the signal analysis unit 3. The strand signal Ss is detected as a signal corresponding to the length of the width of the strand 310 of the wire rope 30 (hereinafter also referred to as "strand width"). The strand width Ws is the length between the irregularities formed on the surface of the strand 310, i.e., the length (distance) between the recesses in the longitudinal direction of one strand 310.

[0045] Furthermore, the strand frequency, which indicates the period of change in the strand signal Ss in the time direction, is determined by the feed speed of the wire rope 30 by the hoisting machine 53 (see FIG. 3) and the strand configuration of the wire rope 30. The strand configuration is determined by the number of strands 311, the twisting method, etc.

[0046] When the feed speed and strand configuration of the wire rope 30 are constant, if a periodic change is detected in the strand frequency of the strand signal Ss, the periodic change indicates a change in tension, i.e., a change in elongation of the wire rope 30.

[0047] Figure 6 is a graph showing the relationship between the elongation of the wire rope 30 and the load applied to the wire rope 30. The vertical axis of the graph represents the load (W), and the horizontal axis represents the elongation (dl). Point a on the graph represents the initial elongation length of the wire rope 30, and point b represents the elastic limit of the wire rope 30. The elastic limit is the limit at which the rope will break due to being unable to withstand the load.

[0048] In a new (unused) wire rope 30, the wires 311 (see Figure 1) are not densely packed, so when a load is applied, the wires come into stable contact with each other. Once the initial elongation stabilizes, the elongation and load in the wire rope 30 become directly proportional, as shown by the straight line ab in the graph. The correlation between the elongation and load of the wire rope when the elongation and load are directly proportional is shown by the following equation (1). In the following equation (1), "dl" is the elongation of the wire rope 30, "W" is the load, "L" is the length of the wire rope 30, "EW" is the tensile modulus of elasticity, and "A" is the cross-sectional area of ​​the wire rope 30.

[0049] dl=W×L / EW×A…Formula (1)

[0050] As described above, since the load on the wire rope 30 is directly proportional to the elongation, it can be said that the change in width of the strand Ss indicates the change in elongation, i.e., the change in tension on the wire rope 30.

[0051] 7 is a graph showing an example of changes in strand frequency when the load applied to the wire rope 30 is changed. The vertical axis of the graph represents the load (W) applied to the wire rope 30, and the horizontal axis represents the strand frequency (Hz).

[0052] The graph shown in Figure 7 shows the measurement results for a wire rope 30 with a nominal diameter of 8 mm and six strands 310. The feed speed of the wire rope 30 is 30 m / min, and the acquisition range of the strand signal Ss is a range of 1.5 m of the total length of the wire rope 30. The solid polygonal line in the graph shows the change in strand frequency when a load of 350 kgf is applied to the wire rope 30, and the dashed polygonal line shows the change in strand frequency when a load of 150 kgf is applied to the wire rope 30.

[0053] As shown in the graph, the strand frequency decreases as the load increases, and increases as the load decreases. This is because an increase in the load on the wire rope 30 causes rope elongation, which changes the width of the strands 310. More specifically, as the wire rope 30 elongates, the number of strands 310 per unit length of the wire rope 30 decreases, which results in a lower strand frequency.

[0054] The tension diagnosis system 100 for the wire rope 30 in this embodiment diagnoses changes in tension in a specific range of the wire rope 30 by analyzing changes in the strand signal Ss in a specific range (section), such as 1.5 m, of the wire rope 30 when it is under load.

[0055] In a first embodiment described below, the tension diagnostic system 100 selects, depending on the diagnosis result, either a process of measuring the entire length (total length) of the wire rope for each model of elevator 50 (see FIG. 3) or a process of measuring the tension preferentially from high-risk portions of the wire rope 30. A high-risk portion of the wire rope 30 is a portion that is considered to be deteriorating due to excessive tension. In a second embodiment described below, the tension diagnostic device 10 measures the tension in the high-risk portion and performs a process of determining whether a wire has been broken when the tension in a partial area of ​​the wire rope 30 is outside the range of reference values.

[0056] [Example 1] First, the first embodiment will be described with reference to Fig. 8. Fig. 8 is a flowchart showing an example of a procedure for diagnosing the tension of the wire rope 30 by the tension diagnosis system 100 according to the first embodiment.

[0057] First, the magnetizer 1 of the tension diagnostic device 10 starts detecting the magnetic signal of the wire rope 30 under the control of the control unit 202 (see FIG. 4) of the terminal device 20 (step S1). The magnetic sensor 12 is installed together with the magnetizer 1 near the wire rope 30, for example, near the hoist 53 (see FIG. 3). Then, by running the cage 51, the wire rope 30 moves in the longitudinal direction. This allows the magnetic sensor 12 to acquire a magnetic signal as time-series data of leakage magnetic flux from the wire rope 30. In step S1, the magnetic sensor 12 measures the magnetic signal in a specific narrow range (e.g., 1.5 m) in the longitudinal direction of the wire rope 30. The magnetic signal detected by the magnetic sensor 12 is subjected to analog processing by the magnetic sensor circuit 2 and then digitally converted by the A / D converter 31 of the signal analysis unit 3 to become the strand signal Ss.

[0058] Next, the signal processor 33 acquires the strand signal Ss (step S2), and then calculates the frequency of the strand signal Ss (strand frequency) based on information such as the feed speed of the wire rope 30 and the strand configuration of the wire rope 30 (step S3).

[0059] Next, the signal processor 33 checks the reference value against the strand frequency calculated in step S3 and compares the two values. The reference value is a strand frequency corresponding to the degree of tension in the wire rope 30, and the frequency is set to the frequency of an undegraded wire rope 30. An undegraded wire rope 30 refers to a wire rope when it is installed in the elevator 50 or immediately after the wire rope 30 is replaced.

[0060] The reference value is associated with information on the correspondence between the magnitude of tension and the frequency of the strand signal and is stored in a table (not shown) etc. This table is set for each type of wire rope 30 and each model of elevator, for example.

[0061] Then, the signal processor 33 determines whether the tension corresponding to the strand frequency is within the range of the reference value (step S4). If it is determined in step S4 that the tension is within the range of the reference value (YES in step S4), the signal processor 33 performs processing to measure the entire wire rope 30 (step S5). In step S5, the signal processor 33 measures the total length (approximately several hundred meters) of the wire rope 30 for each model of elevator 50.

[0062] Next, the signal processor 33 performs a process for determining whether a wire has been broken in the wire rope 30 (step S6). In the process for determining whether a wire has been broken in step S6, the signal processor 33 detects a signal change in leakage magnetic flux caused by a wire break in the wire rope 30, thereby performing a process for identifying the location in the wire rope 30 where the wire break has occurred.

[0063] On the other hand, if it is determined in step S4 that the tension is outside the range of the reference value (step S4 is NO), the signal processor 33 prioritizes measuring the tension in the high-risk area (step S7). The high-risk area is the area where the tension is determined to be outside the range of the reference value. In step S7, the signal processor 33 performs a process to detect a signal change in leakage magnetic flux due to a wire breakage in the high-risk area of ​​the wire rope 30. Next, the signal processor 33 performs a wire breakage determination process for the wire rope 30 based on information on the detected signal change (step S8). After processing step S6 or step S8, the tension diagnosis process for the wire rope 30 according to the first embodiment is terminated.

[0064] According to the above-described first embodiment, it is possible to measure changes in the tension of the wire rope 30. That is, the tension diagnosis system 100 according to the first embodiment can measure the tension of the wire rope 30 by detecting the spring-like expansion and contraction that occurs partially in the wire rope 30 while the car 51 is ascending and descending.

[0065] Furthermore, in the first embodiment, when the tension of the wire rope 30 is within the range of the reference value, it is possible to shorten the measurement of the entire (total length) of the wire rope 30 per model and shorten the inspection cycle for performing the entire measurement. In other words, according to the first embodiment, it is possible to shorten the measurement time of the wire rope 30 by the tension diagnostic system 100 and improve the efficiency of deterioration diagnosis.

[0066] [Example 2] Next, a second embodiment will be described with reference to Fig. 9. Fig. 9 is a flowchart showing an example of a procedure for diagnosing the tension of the wire rope 30 by the tension diagnosis system 100 according to the second embodiment.

[0067] The processing of steps S11 to S14 in Fig. 9 is the same as the processing of steps S1 to S4 in Fig. 8, and therefore description thereof will be omitted. If it is determined in step S14 that the tension of the wire rope 30 is outside the range of the reference value (NO in step S14), the signal processor 33 performs priority measurement of the tension in the high-risk area (step S15). Next, the signal processor 33 performs processing to determine whether a wire has been broken in the high-risk area (step S16).

[0068] On the other hand, if it is determined in step S14 that the tension of the wire rope 30 is within the range of the reference value (YES in step S14), the tension diagnosis process for the wire rope 30 according to the second embodiment ends.

[0069] According to the second embodiment, the wire breakage determination process in the high-risk portion is performed only when the tension in a specific range of the wire rope 30 is outside the range of the reference value. Therefore, according to the second embodiment, the time required for measurement and deterioration diagnosis of the wire rope 30 can be reduced.

[0070] In the second embodiment, when the tension in a specific range of the wire rope 30 is outside the range of reference values, the signal processor 33 performs only the process of determining whether or not the wire has broken in the high-risk portion, but the present invention is not limited to this. When the tension in a specific range of the wire rope 30 is outside the range of reference values, the signal processor 33 may weight the deterioration determination in the high-risk portion and then measure the tension of the entire wire rope 30 (deterioration diagnosis).

[0071] <Example of analysis result display screen configuration> Next, an analysis result display screen showing the analysis results of the tension of the wire rope 30 will be described with reference to Fig. 10. Fig. 10 is a diagram showing an example of the configuration of the analysis result display screen 40.

[0072] As shown in FIG. 10, the analysis result display screen 40 includes a judgment result display section 41, a judgment position display section 42, a model number display section 43, an analysis date and time display section 44, and a wire rope data display section 45.

[0073] The judgment result display section 41 is an area where the judgment result of the deterioration diagnosis of the wire rope 30 by the signal processor 33 is displayed. The judgment result of the deterioration diagnosis of the wire rope 30 may be "normal", "abnormal", etc.

[0074] The determination position display section 42 is an area that displays information about the position where tension was measured in the wire rope 30. The position of the wire rope 30 is indicated by, for example, the distance (m) from the starting point of the wire rope 30. The model number display section 43 is an area where information about the model number of the elevator 50 is displayed. The analysis date and time display section 44 is an area where information on the date and time when the analysis including the tension measurement of the wire rope 30 was performed is displayed.

[0075] The wire rope data display section 45 is an area where information about the wire rope 30 acquired by the signal processor 33 is displayed. In the example shown in Fig. 10, the wire rope data display section 45 displays tension data 451 of the wire rope 30 and strand signal determination data 452 as graphs. The tension data 451 of the wire rope 30 is displayed as a graph with the position of the wire rope 30 on the vertical axis and the tension of the wire rope 30 on the horizontal axis. In the strand signal determination data 452, the range of strand frequencies is displayed as a graph.

[0076] By checking the analysis result display screen 40 as shown in FIG. 10, the user can obtain information regarding the tension of the wire rope 30.

[0077] In the above-described embodiments (Examples 1 and 2), the magnet 11 of the magnetizer 1 excites the wire rope 30, and the magnetic sensor 12 detects the leakage magnetic flux generated from the wire rope 30 due to the excitation, but the present invention is not limited to this. The magnetic sensor 12 may detect the leakage magnetic flux generated from the wire rope 30 without excitation by the magnet 11.

[0078] Furthermore, in the above-described embodiment, an example was given in which the signal analysis unit 3 measures and diagnoses the tension of the wire rope 30 based on the frequency of the strand signal, but the present invention is not limited to this. The signal analysis unit 3 may measure and diagnose the tension of the wire rope 30 based on information about the strand width Ws obtained by analyzing an image of the strand 310 captured by a camera (an example of a sensor unit) not shown. Alternatively, the signal analysis unit 3 may calculate the strand width Ws based on the distance of the wire rope 30 from a concave or convex portion of the strand 310 measured by a laser rangefinder (an example of a sensor unit) not shown or the like and information about the distance, and measure and diagnose the tension of the wire rope 30 based on the information about the calculated strand width Ws.

[0079] It should be noted that the above-described embodiments provide detailed and specific descriptions of the configurations of the devices and systems in order to clearly explain the present invention, and are not necessarily limited to those having all of the configurations described.

[0080] 4, the control lines or information lines shown by solid lines are those considered necessary for explanation, and do not necessarily show all control lines or information lines in the product. In reality, it can be considered that almost all components are interconnected.

[0081] Furthermore, in this specification, processing steps describing chronological processing include not only processing that is performed chronologically in the order described, but also processing that is not necessarily performed chronologically but is performed in parallel or individually (for example, parallel processing or processing by objects). [Explanation of symbols]

[0082] 1...magnetizer, 2...magnetic sensor circuit, 3...signal analysis unit, 10...tension diagnosis device, 11...magnet, 12...magnetic sensor, 20...terminal device, 30...wire rope, 32...signal collector, 33...signal processor, 50...elevator, 51...car, 53...hoisting machine, 100...tension diagnosis system, 310...strand, 311...element wire, 331...control unit

Claims

1. A tension measuring device for measuring the tension of a wire rope formed by twisting a plurality of strands, a sensor unit that acquires information corresponding to a strand width, which is the distance between recesses in the longitudinal direction of one of the strands in a specific section of the wire rope; and a tension measuring unit that calculates a strand frequency indicating a period of change in the time direction of the information corresponding to the strand width acquired by the sensor unit, and measures the tension of the wire rope at a portion where the information corresponding to the strand width is acquired based on the information of the strand frequency. Tension measuring device.

2. The tension measuring unit measures the tension of the wire rope by comparing the strand frequency in correspondence information between preset strand frequencies and tension of the wire rope with the calculated strand frequency.

2. The tension measuring device according to claim 1.

3. a magnetic sensor that detects leakage magnetic flux generated from the strand as a magnetic signal; a signal processor that generates a strand signal that is time-series data of the magnetic signal collected by the magnetic sensor; The information corresponding to the strand width is the strand signal.

3. The tension measuring device according to claim 2.

4. The tension measuring unit diagnoses the deterioration of the wire rope based on information on whether the calculated strand frequency is within a range of reference values ​​that are strand frequencies in the wire rope that is not deteriorated.

4. The tension measuring device according to claim 3.

5. When the tension measuring unit determines that the calculated strand frequency is outside the range of the reference value, the tension measuring unit performs a wire break determination process for the portion of the wire rope from which the strand frequency was acquired, with priority over other portions of the wire rope.

5. The tension measuring device according to claim 4.

6. When the tension measuring unit determines that the calculated strand frequency is within the range of the reference value, it measures the tension of the entire length of the wire rope.

6. The tension measuring device according to claim 5.

7. A tension measurement method using a tension measurement device that includes a sensor unit and a tension measurement unit and measures the tension of a wire rope formed by twisting a plurality of strands, a step in which the sensor unit acquires information corresponding to a strand width, which is a distance between recesses in a longitudinal direction of one of the strands, in a specific section of the wire rope; The tension measuring unit calculates a strand frequency indicating a period of change in the time direction of the information corresponding to the strand width acquired by the sensor unit, and measures the tension of the wire rope at a portion where the information corresponding to the strand width is acquired based on the information of the strand frequency. Tension measurement method.

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