Monitoring method for identifying abrasion of linings of action rod pieces of turnout switch rails

Abstract

According to the monitoring method for identifying the abrasion of the linings of the turnout switch rail actuating rod pieces, when the vibration acceleration reaches the threshold value, overhauling or replacing is conducted, and compared with an existing mode that manual inspection tour is conducted at a skylight point to disassemble equipment for observation, the method does not need to frequently disassemble the equipment to inspect abrasion, the equipment maintenance efficiency is improved, and the maintenance cost is reduced. Errors caused by manual subjective measurement can be avoided; by monitoring the effective acceleration values and kurtosis factors of the action rod piece and the closely-attached switch rail and comparing the effective acceleration values and kurtosis factors with the threshold values, the wear state of the bush is recognized, after the sensor is installed, the vibration acceleration collection process can be continuously conducted, and train operation is not affected; vibration parameters are monitored through vibration, the lining is replaced in time when the vibration parameters reach a threshold value, further impact of a train on the interior of the switch machine can be effectively avoided, and the service life of equipment is prolonged.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of maintenance of railway turnout conversion equipment, in particular to a method for identifying bushing wear of a turnout frog action rod connecting part by monitoring vibration parameters. BACKGROUND

[0002] Turnout conversion equipment is one of the important train operation equipment of the railway, and is a key facility for ensuring train operation safety and improving transportation efficiency. Switch machine and external locking and installation device are the actuators of turnout conversion equipment, which are used for converting and locking the turnout, and indicating and supervising the position and state of the turnout frog or the point rail.

[0003] The monitoring of bushing wear at the rod connecting part plays an important role in the maintenance of the conversion equipment. When the bushing wear exceeds a certain limit, the vibration and impact intensity of the rod will increase due to the increase of the gap between the bushings when the train passes through the turnout, which accelerates the fatigue failure of the conversion equipment.

[0004] At the turnout frog, the identification of bushing wear at the rod connecting parts such as the switch machine action rod, the action connecting rod, and the locking rod is currently mainly based on manual observation by disassembling the rods and other equipment. The disassembly work needs to be done at the window point when the train is not passing, and frequent disassembly of equipment and assembly and debugging not only increase the workload of maintenance personnel, but also reduce the maintenance efficiency.

[0005] Currently, maintenance personnel patrol to disassemble the rods and manually measure the diameter of the bushings at the connecting parts. Since the bushing is circular in shape, the wear of the inner circular surface is not completely the same, and when the measurement position is selected differently, it will affect the measurement result and there will be measurement errors. In addition, the manual disassembly of equipment for bushing wear measurement reduces the equipment maintenance efficiency.

[0006] Chinese invention patent application file CN118293851 A discloses a method for monitoring bushing wear, in which the head of the monitoring sensor is inserted into the bushing at a predetermined position through the external knuckle. When the bushing reaches the predetermined wear amount, the sensor can monitor and trigger the alarm. However, this method requires a hole in the external device (knuckle) of the bushing, which will affect the strength of the external device of the bushing under the vibration and impact of the train.

[0007] Therefore, there is an urgent need for a method that can quickly monitor the wear condition of the frog action rod bushing, monitor the wear of the bushing, and replace the bushing in time when the wear reaches the limit value. SUMMARY

[0008] The application provides a monitoring method for recognizing bushing wear of a switch rail action lever, so that the wear of the bushing can be reflected by monitoring the change of a vibration parameter, and when the vibration parameter of the monitoring sensor reaches a threshold value, it indicates that the wear of the bushing reaches a safety limit.

[0009] In order to solve the above problems, the technical scheme of the application is as follows: a monitoring method for recognizing bushing wear of a switch rail action lever, comprising the following steps: 1) replacing the bushing at the connection of the action lever of the switch rail with a bushing reaching a wear safety limit, collecting the vertical time-domain vibration acceleration signal of the action lever and the closely fitted switch rail after the bushing is replaced; 2) performing data analysis on the vibration acceleration signal, calculating the acceleration effective value and kurtosis factor as the threshold value of the vibration parameter; 3) replacing the bushing reaching the wear safety limit with a normal bushing, monitoring the acceleration effective value and kurtosis factor of the action lever and the closely fitted switch rail; 4) comparing the acceleration effective value and kurtosis factor with the threshold value to recognize the wear state of the bushing.

[0010] The step S1 comprises the following steps: S11: replacing the bushing between the action lever (2) of the switch rail, the action connecting rod (3) and the locking rod (4) with a bushing reaching a wear safety limit, and arranging an acceleration sensor (6) at the action lever (2) and the closely fitted switch rail; the safety limit radius of the bushing after wear is: wherein, is the initial radius of the normal bushing, is the safety limit radius of the bushing after wear, and the radii both refer to the inner diameter of the bushing; is the maximum allowable wear amount of the bushing, and the maximum allowable wear amount of the bushing of the action lever is 0.5 mm.

[0011] S12: collecting the vertical time-domain vibration acceleration signal in one running cycle.

[0012] The steps S11 and S12 collect the vibration acceleration curve.

[0013] The step S2 comprises the following steps: S21: converting the vibration acceleration signal into a frequency spectrum signal through fast Fourier transform (FFT), filtering through a 4th order Butterworth low-pass filter with a cutoff frequency of 1 kHz to eliminate environmental noise interference, and converting the signal from the frequency spectrum into a power spectral density; S22: calculating the effective value of the signal through the power spectral density, and the calculation formula is: wherein, The effective value of the signal. For frequency, This is the lower frequency limit of the power spectral density. The upper frequency limit of the power spectral density. This represents the power spectral density value. S23: Calculate the mean value of the vibration acceleration signal mentioned in step S12. The calculation formula is as follows: In the formula, The mean of the signal. The time domain value of the signal. The signal length; S24: For all vertical time-domain vibration accelerations of the moving rod (2) and the closely attached switch rail in step S12, calculate their kurtosis factors respectively. The calculation formula is as follows: In the formula, For acceleration kurtosis factor, The time domain value of the signal. The mean of the signal. The effective value of the signal. The signal length; S25: Select the maximum values ​​of the effective acceleration value and the kurtosis factor as the threshold values ​​of the effective acceleration value and the kurtosis factor, respectively; The vibration parameter threshold is calculated using steps S21, S22, S23, S24, and S25.

[0014] Step S4 includes the following steps: S41: Compare the effective value of the acceleration of the switch rod (2), the close contact switch rail, the kurtosis factor and the threshold value when the same turnout passes through; S42: When the kurtosis factor of the actuator is less than the threshold, the bushing wear between the actuators is considered to be within the safe limit. S43: When the kurtosis factor of the action rod is greater than the threshold, if the effective value of the acceleration and the kurtosis factor of the close-fitting switch rail are greater than the threshold, it indicates that the excitation is large, and vibration signal is collected for verification. If the effective value of the acceleration and the kurtosis factor of the close-fitting switch rail are less than the threshold, it indicates that the wear of the rod bushing exceeds the safety limit. Further verification shows that the effective value of the acceleration of the action rod (2) also increases. Step S4 uses steps S41, S42, and S43 to identify the wear condition of the bushing.

[0015] The following devices are used to complete steps S1 to 4: switch machine (1), action rod (2), action connecting rod (3), locking rod (4), switch rail (5), acceleration sensor (6), sensor line (7), data acquisition instrument (8), computer (9), network cable (10). The connection between the action rod (2) and the action connecting rod (3) is a metal bushing and the two rods are fixed with bolts. The connection between the action connecting rod (3) and the locking rod (4) is a non-metal bushing and the two rods are fixed with bolts. The acceleration sensor (6) is installed on the side of the action rod (2) at a horizontal distance of 25mm from the end hole of the action rod, so that the normal operation of the switch machine does not affect the signal acquisition. The acceleration sensor (6) is connected to the data acquisition instrument (8) by wire or wireless means. The data acquisition instrument (8) is connected to the computer (9) by wire or wireless means.

[0016] The accelerometer (6) is of ICP type, with a frequency response range of 0.5–10 kHz and a sensitivity of 100 mV / g; the data acquisition instrument 8 supports a 24-bit ADC with a sampling frequency ≥20 kHz.

[0017] The advantages of this invention are: This invention identifies bushing wear by monitoring the effective acceleration value and kurtosis factor of the moving rod and the closely attached switch rail, and comparing them with a threshold. After the sensor is installed, the vibration acceleration acquisition process can be carried out continuously without affecting train operation.

[0018] This invention monitors vibration parameters and replaces the bushing in a timely manner when the vibration parameters reach a threshold, which can effectively prevent further impact from the train on the inside of the switch machine and extend the service life of the equipment.

[0019] This invention provides a monitoring method for identifying wear of bushings on switch switch action rods. This method allows for maintenance or replacement only when the vibration acceleration reaches a threshold. Compared to the current method of manual inspection during track maintenance windows, which involves disassembling equipment for observation, this invention eliminates the need for frequent disassembly to check for wear, thus improving equipment maintenance efficiency and avoiding errors caused by subjective manual measurement.

[0020] The present invention will be further described below with reference to the accompanying drawings of the embodiments. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the installation of the turnout switch rail actuating member according to an embodiment of the present invention; Figure 2 It is a metal bushing between the rods in an embodiment of the present invention; Figure 3 It is a non-metallic bushing (insulating tube) between the rods in the embodiment of the present invention. Figure 4This is a flowchart of the method for identifying wear of the switch switch rod bushing according to an embodiment of the present invention; Figure 5A It is a normal bushing time-domain curve; Figure 5B It is the wear limit bushing time domain curve; Figure 5C Normal bushing frequency domain curve; Figure 5D Wear limit bushing frequency domain curve.

[0022] In the diagram: 1. Switch machine; 2. Actuating rod; 3. Actuating connecting rod; 4. Locking rod; 5. Switch rail; 6. Accelerometer; 7. Sensor cable; 8. Data acquisition instrument; 9. Computer; 10. Network cable. Detailed Implementation

[0023] To further illustrate the technical means and effects of the present invention in achieving its intended purpose, the specific implementation methods, structural features and effects of the present invention are described in detail below with reference to the accompanying drawings and embodiments.

[0024] like Figure 1 As shown, this invention relates to a monitoring method for identifying wear of bushings on switch switch rods, comprising: a switch machine 1, an actuating rod 2, an actuating connecting rod 3, a locking rod 4, a switch rail 5, an acceleration sensor 6, a sensor cable 7, a data acquisition instrument 8, a computer 9, and a network cable 10. The connection between the actuating rod 2 and the actuating connecting rod 3 is a metal bushing. Figure 2 As shown, the two rods are fixed with bolts. The connection between the action connecting rod 3 and the locking rod 4 is a non-metallic bushing (insulating tube). Figure 3 As shown, the two rods are fixed with bolts. The acceleration sensor 6 is installed on the side of the action rod 2, and the horizontal distance from the end hole of the action rod is 25mm. The normal operation of the switch machine does not affect the signal acquisition. The acceleration sensor 6 is connected to the data acquisition instrument 8 by wire or wireless means, and the data acquisition instrument 8 is connected to the computer 9 by wire or wireless means.

[0025] The accelerometer 6 is an ICP type with a frequency response range of 0.5–10 kHz and a sensitivity of 100 mV / g; the data acquisition instrument 8 supports a 24-bit ADC with a sampling frequency ≥20 kHz.

[0026] like Figure 4 , Figure 5A , Figure 5B , Figure 5C , Figure 5D As shown.

[0027] This invention relates to a monitoring method for identifying wear of the bushing of a turnout switch rail actuator, comprising the following steps: S1: Replace the bushing at the connection of the actuator at the switch rail with a bushing that has reached the wear safety limit, and collect the vertical time-domain vibration acceleration curves of the actuator and the close-fitting switch rail after the bushing replacement when the train passes. In this step, the vibration acceleration curve is acquired using steps S11 and S12; S11: Replace the bushings between the switch rail actuating rod 2, actuating connecting rod 3, and locking rod 4 with bushings that have reached their wear safety limit, and install an acceleration sensor 6 at the actuating rod 2 and the point where it is in close contact with the switch rail; the safety limit radius after the bushing wears out is: In the formula, The initial radius of the normal bushing. This refers to the safe limit radius after bushing wear; all radii refer to the inner diameter of the bushing. The maximum permissible wear of the bushing is determined according to the "Technical Standards for High-Speed ​​Railway Signal Maintenance Rules" (China Railway Transportation

[2015] No. 332) and the "Technical Standards for Conventional Railway Signal Maintenance Rules" (China Railway Transportation

[2015] No. 238), which define the maximum permissible wear of the bushing for the actuating rod. It is 0.5mm.

[0028] S12: Acquire the vertical time-domain vibration acceleration signal within one operating cycle.

[0029] S2: Perform data processing and analysis on the vibration acceleration signal, calculate the effective value of acceleration and kurtosis factor, and use them as vibration parameter thresholds; In this step, the vibration parameter threshold is calculated using steps S21, S22, S23, S24, and S25; S21: The vibration acceleration signal is converted into a spectrum signal by Fast Fourier Transform (FFT), and then filtered by a 4th-order Butterworth low-pass filter (cutoff frequency 1 kHz) to remove environmental noise interference; and the signal is converted from spectrum to power spectral density; S22: The effective value of the signal is obtained by calculating the power spectral density. The calculation formula is as follows: In the formula, The effective value of the signal. For frequency, This is the lower frequency limit of the power spectral density. The upper frequency limit of the power spectral density. This represents the power spectral density value. S23: Calculate the mean value of the vibration acceleration signal mentioned in step S12. The calculation formula is as follows: In the formula, The mean of the signal. The time domain value of the signal. The signal length; S24: For all vertical time-domain vibration accelerations of the moving rod and the closely attached switch rail in step S12, calculate their kurtosis factors. The calculation formula is as follows: In the formula, For acceleration kurtosis factor, The time domain value of the signal. The mean of the signal. The effective value of the signal. The signal length; S25: Select the maximum values ​​of the effective acceleration value and the kurtosis factor as the threshold values ​​of the effective acceleration value and the kurtosis factor, respectively.

[0030] S3: Replace the bushing with the one that has reached the wear safety limit with a normal bushing, and monitor the effective value of the acceleration and the kurtosis factor of the actuating rod and the close-fitting switch.

[0031] S4: Compare the effective value of acceleration, kurtosis factor and threshold value to identify the bushing wear state.

[0032] In this step, steps S41, S42, and S43 are used to identify the wear condition of the bushing; S41: Compare the effective values ​​of the acceleration of the lever 2 and the close-fitting switch rail, the kurtosis factor and the threshold value when the same turnout passes through; S42: When the kurtosis factor of the actuator is less than the threshold, the bushing wear between the actuators is considered to be within the safe limit. S43: When the kurtosis factor of the actuator is greater than the threshold, if the effective value of the acceleration and the kurtosis factor of the close-fitting switch are greater than the threshold, it indicates that the excitation is large, and vibration signal acquisition should continue to be performed for verification; if the effective value of the acceleration and the kurtosis factor of the close-fitting switch are less than the threshold, it indicates that the wear of the bushing of the actuator exceeds the safety limit, and further verification is required that the effective value of the acceleration of actuator 2 also increases.

[0033] The following is the experimental verification data.

[0034] False positive rate and sensitivity analysis of the present invention When the vehicle speed increases from 220km / h to 320km / h, the ratio of the kurtosis factor at 300km / h to that at 220km / h is within 1.5 for a normal bushing, and the kurtosis factor is relatively stable. However, when the bushing reaches the wear safety limit, its kurtosis factor changes significantly, and the abnormal kurtosis factor can reach more than twice the normal kurtosis factor.

[0035] Comparative experiment with existing technologies Compared to CN 118293851A, this invention requires no drilling for installation, no need to install alarms, reduces the number of sensors by 50%, and eliminates the need to consider the continuity of sensor detection circuits, thus improving maintenance efficiency by 60%.

[0036] This invention reflects wear by monitoring vibration acceleration, requiring only the monitoring and processing of vibration data; the monitoring part only requires the installation of a sensor, making the installation method simple. It does not require altering the structure of the external bushing device and does not affect the mechanical strength of the external device.

[0037] The above description is only a preferred embodiment of the present invention and is not intended to limit the scope of the present invention. Any changes, substitutions or improvements made to the structure and features described in the scope of the present invention should be included within the protection scope of the present invention.

Claims

1. A monitoring method for identifying wear of the bushing of the switch switch rod, characterized in that: Includes the following steps: S1: Replace the bushing at the connection of the actuator at the switch rail with a bushing that has reached the wear safety limit, and collect the vertical time-domain vibration acceleration curves of the actuator and the close-fitting switch rail after the bushing replacement when the train passes. S2: Perform data processing and analysis on the vibration acceleration signal, calculate the effective value of acceleration and kurtosis factor, and use them as vibration parameter thresholds; S3: Replace the bushing with the one that has reached the wear safety limit with a normal bushing, and monitor the effective value of the acceleration and the kurtosis factor of the actuating rod and the close-fitting switch rail; S4: Compare the effective value of acceleration, kurtosis factor and threshold value to identify the bushing wear state.

2. The monitoring method for identifying wear of the bushing of the switch switch rod according to claim 1, characterized in that: the step... S1 includes the following steps: S11: Replace the bushings between the switch rail actuating rod (2), actuating connecting rod (3), and locking rod (4) with bushings that have reached the wear safety limit, and place an acceleration sensor (6) at the actuating rod (2) and the close contact point with the switch rail; the safety limit radius after the bushing wears out is: In the formula, The initial radius of the normal bushing. This refers to the safe limit radius after bushing wear; all radii refer to the inner diameter of the bushing. The maximum permissible wear of the bushing; the maximum permissible wear of the bushing of the actuating rod. It is 0.5mm; S12: Acquire the vertical time-domain vibration acceleration signal within one operating cycle; Steps S11 and S12 collect the vibration acceleration curve.

3. The monitoring method for identifying wear of the bushing of the switch switch rod according to claim 1, characterized in that: the step... S2 includes the following steps: S21: The vibration acceleration signal is converted into a spectrum signal by Fast Fourier Transform (FFT), then filtered by a 4th-order Butterworth low-pass filter with a cutoff frequency of 1 kHz to remove environmental noise interference; and the signal is converted from spectrum to power spectral density. S22: The effective value of the signal is obtained by calculating the power spectral density. The calculation formula is as follows: In the formula, The effective value of the signal. For frequency, This is the lower frequency limit of the power spectral density. The upper frequency limit of the power spectral density. This represents the power spectral density value. S23: Calculate the mean value of the vibration acceleration signal mentioned in step S12. The calculation formula is as follows: In the formula, The mean of the signal. The time domain value of the signal. The signal length; S24: For all vertical time-domain vibration accelerations of the moving rod (2) and the closely attached switch rail in step S12, calculate their kurtosis factors respectively. The calculation formula is as follows: In the formula, For acceleration kurtosis factor, The time domain value of the signal. The mean of the signal. The effective value of the signal. The signal length; S25: Select the maximum values ​​of the effective acceleration value and the kurtosis factor as the threshold values ​​of the effective acceleration value and the kurtosis factor, respectively; The vibration parameter threshold is calculated using steps S21, S22, S23, S24, and S25.

4. The monitoring method for identifying wear of the bushing of the switch switch rod according to claim 1, characterized in that: the step... S4 includes the following steps: S41: Compare the effective value of the acceleration of the switch rod (2), the close contact switch rail, the kurtosis factor and the threshold value when the same turnout passes through; S42: When the kurtosis factor of the actuator is less than the threshold, the bushing wear between the actuators is considered to be within the safe limit. S43: When the kurtosis factor of the action rod is greater than the threshold, if the effective value of the acceleration and the kurtosis factor of the close-fitting switch rail are greater than the threshold, it indicates that the excitation is large, and vibration signal is collected for verification. If the effective value of the acceleration and the kurtosis factor of the close-fitting switch rail are less than the threshold, it indicates that the wear of the rod bushing exceeds the safety limit. Further verification shows that the effective value of the acceleration of the action rod (2) also increases. Step S4 uses steps S41, S42, and S43 to identify the wear condition of the bushing.

5. The monitoring method for identifying wear of the bushing of the switch switch rod according to claim 1, characterized in that: The following devices are used to complete steps S1 to 4: switch machine (1), action rod (2), action connecting rod (3), locking rod (4), switch rail (5), acceleration sensor (6), sensor line (7), data acquisition instrument (8), computer (9), network cable (10). The connection between the action rod (2) and the action connecting rod (3) is a metal bushing and the two rods are fixed with bolts. The connection between the action connecting rod (3) and the locking rod (4) is a non-metal bushing and the two rods are fixed with bolts. The acceleration sensor (6) is installed on the side of the action rod (2) at a horizontal distance of 25mm from the end hole of the action rod, so that the normal operation of the switch machine does not affect the signal acquisition. The acceleration sensor (6) is connected to the data acquisition instrument (8) by wire or wireless means. The data acquisition instrument (8) is connected to the computer (9) by wire or wireless means.

6. The monitoring method for identifying wear of the bushing of the switch switch rod according to claim 5, characterized in that: The accelerometer (6) is of ICP type, with a frequency response range of 0.5–10 kHz and a sensitivity of 100 mV / g; the data acquisition instrument 8 supports a 24-bit ADC with a sampling frequency ≥20 kHz.

Images