Method for repairing worn molded surface of pantograph slide plate

Abstract

The invention discloses a method for repairing an abraded molded surface of a pantograph slide plate, and relates to the technical field of rail transit operation and maintenance and state monitoring. Comprising the following steps: extracting a profile curve and a groove characteristic parameter of an abrasion molded surface of the pantograph slide plate; analyzing an association rule of the groove characteristic parameters, the abrasion performance parameters and the dynamic interaction parameters through a current-carrying friction wear test; based on the simulation of the pantograph-catenary coupling model, determining a repair critical threshold for ensuring the stable performance of the pantograph-catenary system; and according to the repair critical threshold value, a corresponding repair means is adopted to repair the worn molded surface of the pantograph slide plate, so that the repaired slide plate profile meets the requirement of stable system performance. According to the method, by systematically extracting profile feature parameters and combining a current-carrying friction wear test and pantograph-catenary coupling model simulation, the association rule of groove damage and system performance is defined, a scientific repair critical threshold value is determined, and an accurate theoretical basis is provided for repair work.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of rail transit operation and maintenance technology and state monitoring technology, and more particularly to a pantograph slide plate wear profile repair method. BACKGROUND

[0002] As the core component of electric energy transmission of electrified railway, the dynamic contact characteristics of pantograph-catenary system directly determine the current collection quality and operation safety of the train. Under the condition of high-speed sliding current-carrying, the contact interface often gradually forms a profile curve with specific geometric characteristics under the joint action of mechanical wear and electrical wear. When the contact point passes through the curve area, it is easy to cause continuous arc due to sudden contact loss, resulting in serious ablation of the contact surface, which not only causes high-temperature softening, erosion damage and increase of abrasive dust of the material, but also significantly aggravates mechanical wear and electrical wear, eventually leading to the overall degradation of the wear performance and dynamic performance of the pantograph-catenary system, which seriously threatens the safety of train operation.

[0003] The appearance of different profile curves often leads to deterioration of contact pressure distribution, edge stress concentration and reduction of effective contact area, thereby causing increase of current density, abnormal vibration and accumulation of arc energy, and accelerating material failure. Existing research shows that excessive normal contact pressure can significantly increase the wear rate and change the vibration characteristics of the system, and this deterioration effect is more significant when large current and interface damage coexist. Therefore, studying the evolution law of wear performance of the contact pair after damage and its influence on the matching performance of the pantograph-catenary system has become a key problem to be solved in the current rail transit field. The present application can provide accurate evaluation basis and decision support for on-site operation and maintenance, and has important engineering value for inhibiting abnormal wear, prolonging the service life of components and improving the operation safety and economy of the system.

[0004] Therefore, the present application provides a pantograph slide plate wear profile repair method to solve the problems existing in the prior art, which is a problem to be solved by those skilled in the art. SUMMARY

[0005] Therefore, the present application provides a pantograph slide plate wear profile repair method to solve the problems existing in the prior art, which is a problem to be solved by those skilled in the art.

[0006] In order to achieve the above purpose, the present application provides the following technical scheme: A pantograph slide plate wear profile repair method, comprising the following steps: S1, extracting the profile curve and groove characteristic parameters of the pantograph slide plate wear profile; S2, analyzing the correlation between the groove characteristic parameters and the wear performance parameters and the dynamic interaction parameters through the current-carrying friction and wear test. S3, determining a repair critical threshold value for ensuring performance stability of the pantograph-catenary system based on the pantograph-catenary coupling model simulation; S4, repairing the pantograph slide plate wear profile according to the repair critical threshold value by using a corresponding repair method, so that the repaired slide plate profile meets the system performance stability requirements.

[0007] Optionally, the groove characteristic parameters in S1 include: groove width, groove depth, and groove depth-length ratio λ, the groove depth-length ratio λ being a ratio of the groove depth to the groove width.

[0008] Optionally, the extraction range of the groove width in S1 is 10-160 mm, and the extraction range of the groove depth is 0-20 mm; when extracting, the asymmetric profile is equivalent to a plurality of grooves with the same width but different depths for characteristic parameter statistics.

[0009] Optionally, the wear performance parameters in S2 include: wear rate, friction coefficient, and contact resistance, and the dynamic interaction parameters include: vibration acceleration, normal force statistical value, and arcing rate.

[0010] Optionally, the CTA120 type contact line is used for pairing test with the slide plate to be tested in the load carrying friction and wear test in S2.

[0011] Optionally, the repair critical threshold value in S3 is: groove depth-length ratio λ < 0.15 and curvature slope k g ≤0.55.

[0012] Optionally, the pantograph-catenary coupling model in S3 is a dynamic model considering the damage characteristics of the contact pair groove, which is used to quantitatively analyze the influence of the groove width, groove depth, and groove depth-length ratio on the system contact force distribution, vibration response, and arcing characteristics.

[0013] Optionally, the repair method in S4 includes: surface smoothness improvement and mechanical polishing repair, when the groove depth is ≤3 mm, directly polishing to maintain the surface smoothness, and when the groove depth is >3 mm, first performing mechanical polishing shaping, and then polishing to restore the surface smoothness.

[0014] Optionally, 800# and 1500# sandpaper are used for longitudinal and transverse polishing in sequence during the mechanical polishing repair, and after polishing, the surface is washed with 95% alcohol.

[0015] Optionally, the slide plate profile is rechecked after repair to ensure that the groove depth-length ratio λ < 0.15, the curvature slope k g ≤0.55, and the contact force distribution uniformity meets the current collection quality requirements of the pantograph-catenary system.

[0016] According to the above technical solution, compared with the prior art, the present application provides a pantograph slide plate wear profile repair method, which has the following advantages: 1) This invention systematically extracts profile feature parameters, combines current-carrying friction and wear tests with pantograph-catenary coupling model simulation, clarifies the correlation between groove damage and system performance, determines the scientific critical threshold for repair, and provides a precise theoretical basis for repair work; 2) The repair methods are highly targeted, and different repair methods are used according to the depth of the groove, which not only ensures the repair effect, but also avoids material waste caused by over-repair, effectively reducing operation and maintenance costs; 3) The repaired skateboard profile satisfies λ < 0.15 and k g The requirement of ≤0.55 can significantly improve the contact pressure distribution, reduce edge stress concentration and arcing, suppress the synergistic deterioration of mechanical wear and electrical wear, and improve the current collection quality and operational reliability of the pantograph-catenary system; 4) This method is simple to operate and highly practical. It can be directly applied to on-site operation and maintenance work, extend the service life of the pantograph sliding plate, reduce the total life cycle cost of the pantograph-catenary system, and has important engineering application value. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0018] Figure 1 A flowchart illustrating a method for repairing the worn surface of a pantograph sliding plate provided by the present invention; Figure 2 The actual shape of the skateboard provided by the present invention is shown in the figure; where a is W-shaped wear, b is deep U-shaped wear, and c is single-sided V-shaped wear. Figure 3a The profile curve diagram provided for this invention; Figure 3b This invention provides a profile curve feature parameter extraction diagram; Figure 4a The width statistics of the profile curve feature parameter statistical chart provided by the present invention; Figure 4b The depth statistics results of the profile curve feature parameter statistical graph provided by the present invention; Figure 5a The time history curve of the current-carrying friction and wear test provided by the present invention; Figure 5b The statistical values ​​of the current-carrying friction and wear test provided by this invention are distributed along the transverse direction of the sliding plate; Figure 6 The simulation time history curve provided for this invention; Figure 7 The simulation results provided by this invention are distributed along the lateral direction of the skateboard. Figure 8a The diagram showing the variation of the standard deviation of contact force with the characteristic parameters of the groove provided by this invention; Figure 8b The maximum contact force varies with the groove characteristic parameters as provided by this invention; Figure 8c The diagram showing the variation of the minimum contact force with the characteristic parameters of the groove provided by this invention; Figure 8d The graph showing the variation of the average acceleration value with the characteristic parameters of the groove provided by this invention; Figure 9 The graph shows the variation of wear performance parameters with groove characteristic parameters provided by the present invention. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] See Figure 1 As shown, this invention discloses a method for repairing the worn surface of a pantograph sliding plate, comprising the following steps: S1. Extract the profile curve and groove feature parameters of the pantograph sliding plate wear surface; S2. The correlation between groove characteristic parameters, wear performance parameters, and dynamic interaction parameters was analyzed through current-carrying friction and wear tests. S3. Based on the simulation of the pantograph-catenary coupling model, determine the critical repair threshold to ensure the stable performance of the pantograph-catenary system; S4. Based on the critical repair threshold, use corresponding repair methods to repair the wear surface of the pantograph sliding plate so that the repaired sliding plate profile meets the system performance stability requirements.

[0021] Furthermore, the groove feature parameters in S1 include: groove width, groove depth, and groove depth-to-length ratio λ, where λ is the ratio of groove depth to groove width.

[0022] Furthermore, in S1, the extraction range of groove width is 10~160mm, and the extraction range of groove depth is 0~20mm; during extraction, the asymmetric profile is equivalent to several grooves with the same width but different depths for feature parameter statistics.

[0023] Specifically, urban rail trains undergo maintenance after each day's operation, including monitoring the wear and tear on the pantograph sliding plates. Typically, the sliding plate shape is either U-shaped or W-shaped, depending on the actual conditions of the operating line. Figure 2 As shown in a and b, the subway lines currently exhibit numerous abnormal wear conditions, primarily including a significant increase in wear rate and abnormal slide plate profiles. A single-sided V-shaped groove is one such abnormal profile. Figure 2 As shown in c, its characteristic is that a relatively deep groove appears on one side of the midpoint of operation, with a maximum of nearly 20mm, while the other side is relatively flat. The abnormal profile will worsen the current collection quality of the pantograph-catenary system, and may even cause the contact pair to go offline, burn the contact surface, and cause more serious wear and worse current collection quality. In more serious cases, it will affect the safety of train operation and reduce the service life of the pantograph.

[0024] Figure 3a and Figure 3b The skateboard profiles tested during a subway operation window show that different skateboard profiles are basically symmetrically distributed around the center (where the pull-out value is 0). To facilitate the quantitative analysis of skateboard wear profiles, the skateboard profiles are divided into grooves of different widths and depths, such as... Figure 3b The purple curved groove V3 shown has the same height at both ends, therefore it is equivalent to a single groove working condition. Figure 3b The groove formed by the black curve V1 and the blue curve V2 shown has different heights at both ends, so it is equivalent to two grooves with the same width but different depths.

[0025] To facilitate the statistical analysis of the width and depth distribution of grooves during actual line operation, based on the extraction of the aforementioned groove characteristic parameters, numerical statistical analysis was performed on the collected slide profile curves. Figure 3a It can be seen that the groove width values ​​are mainly concentrated between 30 and 160 mm, with the most concentrated value being 60 mm; from Figure 3b It can be seen that the most widespread groove depth distribution is within 0.5mm, followed by a relatively wide distribution in the 2-3mm range. Since the statistical data represents skateboards under normal service conditions, the wear depth is relatively small. However, considering the frequent occurrence of abnormal wear on current skateboards, the groove depth can reach over 15mm in a short period. Figure 2 In the case of 'c', the depth of the carbon strip on a new skateboard is usually around 20mm to 23mm. Therefore, in order to investigate the changes in flow performance after different groove depths occur (including abnormal wear) and to propose corresponding treatment measures, the groove width range is set to 10 to 160mm and the depth is set to 0 to 20mm.

[0026] Furthermore, the wear performance parameters in S2 include: wear rate, friction coefficient and contact resistance, and the dynamic interaction parameters include: vibration acceleration, normal force statistics and arcing rate.

[0027] Furthermore, the parameters for the current-carrying friction and wear test in S2 are set as follows: current 200A, normal force 40N, sliding speed 60km / h, and a CTA120 contact wire is used to perform a pairing test with the test slide.

[0028] Specifically, from Figure 4a , Figure 4b It can be seen that the 60mm groove width has the highest proportion. Therefore, experiments were conducted using a 60mm groove width skateboard with different groove depths and CTA120 contact wire, with material properties consistent with actual circuit applications. Each experiment included sanding the contact wire and skateboard longitudinally and laterally with 800# and 1500# sandpaper. After each sanding, the surface was rinsed and wiped with 95% alcohol to remove any residual debris and foreign particles.

[0029] The distribution of dynamic parameters along the lateral side of the contact pair surface is very important for further exploring the evolution of wear performance and the weight of each parameter in relation to wear performance. Figure 5a and Figure 5b This displays data on acceleration, force, and arc energy during the experiment, at different numbers of cycles during the sliding process (c1~c5 represent the first to fifth cycles, respectively). According to... Figure 5a It can be seen that the response parameters fluctuate with time during the experiment, with particularly dramatic fluctuations at 2.1s and 4.9s. The data can be converted into a lateral distribution along the contact pair as follows: Figure 5b As shown, the horizontal axis represents the simulated pull-out value with the center of the slide plate as 0, and the vertical axis represents the average value of each parameter, where -30~30mm represents the set groove position. It can be seen that during the stage where the contact point passes through the groove, the acceleration, tangential force, and arc energy are all greater than those at the flat part of the contact pair. This indicates that the formation of the groove will increase both electrical and mechanical wear during the sliding electrical contact process of the contact pair, and the deterioration mainly occurs at the groove, further aggravating the unevenness of the contact pair.

[0030] Furthermore, the critical repair threshold in S3 is: the groove depth-to-length ratio λ < 0.15 and the curvature slope k. g ≤0.55.

[0031] Furthermore, the pantograph-catenary coupling model in S3 is a dynamic model that considers the damage characteristics of the contact pair groove, used to quantitatively analyze the influence of groove width, groove depth, and groove depth-to-length ratio on the system's contact force distribution, vibration response, and arcing characteristics.

[0032] For details, see Figure 6The figure shows the time history curves of some simulation results. The groove width is set to 30mm, and the depth is 5~20mm. When the contact pair passes through the groove of the sliding plate, the contact force undergoes a sudden change, momentarily decreasing and then increasing after a period of time. This leads to an increase in Fmax and a decrease in Fmin when performing contact force statistical analysis. In some cases, Fc even becomes 0 when the groove depth is 20mm, which is usually indicative of poor current collection quality and should be avoided as it can cause arcing and erosion of the sliding plate and contact line. The sudden change in contact force begins at the edge of the sliding plate groove. Due to the abrupt change in tight contact, this is related to… Figure 5a and Figure 5b The experimental results shown are consistent.

[0033] In tribology, the uniformity of load distribution on the contact surface is an important parameter. Different intervals are defined by the lateral distribution of the sliding plate, and the lateral distribution coefficient of the contact force is defined as shown in the following formula.

[0034]

[0035] in, Fc ij For the first i The first interval j A contact force, Fc ave This represents the average contact force. n This represents the value of the contact force within this interval. ζ i For the first i Lateral distribution coefficient of contact force in each interval.

[0036] The magnitude of this difference can indicate the uniformity of load distribution, and is used to evaluate dynamic interaction performance and wear performance. See also Figure 7 As shown w g When h is 30, different h g Next ζ i The changes.

[0037] It can be clearly observed that the change in Δζi is larger at the groove, due to h g It is 0.13 at 5mm, and then to h. g The value of 1.25 at 20mm is 9.62 times higher, which has a great impact on the change of load at different positions, thus affecting the wear performance, and may even lead to the instability of the friction system during the actual operation of the line.

[0038] Furthermore, the repair methods in S4 include: surface smoothness improvement and mechanical grinding repair. When the groove depth is ≤3mm, it is directly ground to maintain the surface smoothness. When the groove depth is >3mm, mechanical grinding is performed first to reshape the surface, and then the surface smoothness is restored by grinding.

[0039] Furthermore, during mechanical polishing repair, 800# and 1500# sandpaper are used to polish longitudinally and transversely in sequence. After polishing, the surface is rinsed and wiped with 95% alcohol.

[0040] Furthermore, the skateboard's profile was re-inspected after repair to ensure the groove's depth-to-length ratio was correct. λ <0.15, curvature slope k g The contact force distribution is ≤0.55, and the uniformity of the contact force distribution meets the current collection quality requirements of the pantograph-catenary system.

[0041] For details, see Figure 8a - Figure 8d As shown, F std The changing trend, in k g When λ is less than or equal to 0.65, i.e., when λ is less than or equal to 0.18, the standard deviation of the contact force hardly changes, and has little impact on the flow quality. Similarly, within this threshold range... F max and Accave The changes were also relatively minor. k g When λ is less than or equal to 0.55, that is, when λ is less than or equal to 0.15, F min The trend of change is increasing. Furthermore, when... k g When the value exceeds 1.55, i.e., λ is greater than 0.4, the arcing rate begins to increase. See also... Figure 9 The figure shows the change in wear rate. k g More than 1.55, that is λ When the value is greater than 0.4, the arc rate changes significantly. The main change is the sharp increase in the arc rate, while other trends are related to changes in force.

[0042] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0043] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for repairing the worn surface of a pantograph sliding plate, characterized in that, Includes the following steps: S1. Extract the profile curve and groove feature parameters of the pantograph sliding plate wear surface; S2. The correlation between groove characteristic parameters, wear performance parameters, and dynamic interaction parameters was analyzed through current-carrying friction and wear tests. S3. Based on the simulation of the pantograph-catenary coupling model, determine the critical repair threshold to ensure the stable performance of the pantograph-catenary system; S4. Based on the critical repair threshold, use corresponding repair methods to repair the wear surface of the pantograph sliding plate so that the repaired sliding plate profile meets the system performance stability requirements.

2. The method for repairing the worn surface of a pantograph sliding plate according to claim 1, characterized in that, The groove feature parameters in S1 include: groove width, groove depth, and groove depth-to-length ratio λ, where λ is the ratio of groove depth to groove width.

3. The method for repairing the worn surface of a pantograph sliding plate according to claim 2, characterized in that, The extraction range of groove width in S1 is 10~160mm, and the extraction range of groove depth is 0~20mm. During extraction, the asymmetric profile is equivalent to several grooves with the same width but different depths for feature parameter statistics.

4. The method for repairing the worn surface of a pantograph sliding plate according to claim 1, characterized in that, The wear performance parameters in S2 include: wear rate, friction coefficient and contact resistance; the dynamic interaction parameters include: vibration acceleration, normal force statistics and arcing rate.

5. The method for repairing the worn surface of a pantograph sliding plate according to claim 1, characterized in that, The S2 current-carrying friction and wear test uses a CTA120 contact wire paired with the test slide plate.

6. The method for repairing the worn surface of a pantograph sliding plate according to claim 1, characterized in that, The critical repair threshold in S3 is: groove depth-to-length ratio λ < 0.15 and curvature slope k. g ≤0.

55.

7. The method for repairing the worn surface of a pantograph sliding plate according to claim 2, characterized in that, The pantograph-catenary coupling model in S3 is a dynamic model that considers the damage characteristics of the contact pair grooves. It is used to quantitatively analyze the influence of groove width, groove depth, and groove depth-to-length ratio on the system's contact force distribution, vibration response, and arcing characteristics.

8. The method for repairing the worn surface of a pantograph sliding plate according to claim 1, characterized in that, The repair methods in S4 include: surface smoothness improvement and mechanical grinding repair. When the groove depth is ≤3mm, it is directly ground to maintain the surface smoothness. When the groove depth is >3mm, mechanical grinding is performed first to shape it, and then the surface smoothness is restored by grinding.

9. A method for repairing the worn surface of a pantograph sliding plate according to claim 8, characterized in that, When mechanically grinding and repairing, use 800# and 1500# sandpaper to grind longitudinally and transversely in sequence. After grinding, rinse and wipe the surface with 95% alcohol.

10. A method for repairing the worn surface of a pantograph sliding plate according to claim 1, characterized in that, After repair, the skateboard profile is re-inspected to ensure that the groove depth-to-length ratio λ < 0.15 and the curvature slope k g The contact force distribution is ≤0.55, and the uniformity of the contact force distribution meets the current collection quality requirements of the pantograph-catenary system.

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