A heavy haul railway small-radius curve corrugation disease comprehensive treatment method
By employing a comprehensive approach that combines dynamic models and friction adjustment, the problem of rail corrugation on small-radius curves in heavy-haul railways was solved, achieving effective rail protection and long-term track stability.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- INNER MONGOLIA JINHUA PORT LOGISTICS CO LTD CHIFENG RAILWAY BRANCH
- Filing Date
- 2024-11-15
- Publication Date
- 2026-06-09
AI Technical Summary
Existing technologies are insufficient to effectively suppress the corrugation defects on the surface of rails on small-radius curves in heavy-haul railways, and conventional treatment methods can easily lead to accelerated rail wear, affecting the service life of rails and the safety of train operation.
By comprehensively considering various factors, and employing methods such as large-scale grinding, milling, small-scale grinding, and rail side lubrication, combined with a real-parameter vehicle-track coupled dynamics model, a targeted treatment plan was developed to adjust the friction coefficient, improve the wheel-rail relationship, and extend the service life of the rails.
It significantly inhibited the development of rail corrugation, slowed down rail wear, extended rail service life, improved the stability and safety of the line, and reduced maintenance costs.
Smart Images
Figure CN119578063B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of engineering technology, specifically, it is a comprehensive treatment method for corrugation defects on small-radius curves of heavy-haul railways. Technical Background
[0002] Heavy-haul railways are a vital channel for freight transport in my country. With the increasing demand for goods year by year, the freight volume of heavy-haul railways is also rising annually. For example, the Shuohuang Railway has an annual transport volume of 360 million tons, and the Daqin Railway has an annual transport volume of 420 million tons. As a crucial piece of railway track equipment, rails bear the load of trains. Affected by a combination of factors such as track condition, line conditions, and rolling stock, rails gradually deteriorate during service, resulting in defects such as corrugation and spalling on the rail surface. This is especially true on small-radius curves of heavy-haul railways, where these defects not only occur frequently but also develop rapidly. Spalling defects on the rail surface are caused by wheel-rail rolling contact fatigue. This fatigue leads to fatigue cracks on the rail surface. Under shear force, these fatigue cracks gradually expand, eventually forming spalling. Spalling can be removed by grinding.
[0003] Rail corrugation is influenced by various factors, such as poor wheel-rail interaction, uneven track bed elasticity, and stick-slip vibration between the wheel and rail. Once rail corrugation occurs, it increases the wheel-rail interaction force, leading to accelerated damage to locomotives, rolling stock, and track components, and affecting the service life of the rails. In addition, corrugation increases vehicle vibration, causing serious damage to the fastening system and reducing track bed stability, resulting in track bed hardening and other issues that affect train operation safety.
[0004] Currently, the commonly used methods for treating rail corrugation defects are mainly divided into three types:
[0005] Method 1: Use a milling machine to mill the corrugated sections of the rail. This method can effectively remove the corrugation defects on the surface of straight and curved rails. However, when dealing with corrugation on the surface of curved rails, if there is side wear on the rail, the gauge angle is often not milled, and the corrugation defects on the rail surface cannot be effectively removed.
[0006] Method 2: Using large-scale grinding machines to treat rail surface corrugation. This method optimizes the rail profile and improves the wheel-rail relationship while removing rail surface corrugation defects. It has a significant inhibitory effect on the development of rail surface corrugation defects in conventional railways and high-speed railways. However, in heavy-haul railways, the wheel-rail interaction force and vibration are greater, the rail wear is greater, and the rail profile changes rapidly. This weakens the inhibitory effect of rail profile grinding on rail surface corrugation defects. For example, severe rail surface corrugation appeared one month after the rail profile of the R400m curve on the Shuohuang Railway was ground.
[0007] Method 3: Use small grinding machines to treat localized corrugations. Grinding rail corrugations with small machines is usually a method used when large machines are insufficient and cannot be used in time. However, the grinding process does not specifically constrain the target profile, failing to improve wheel-rail relationships and inhibit the development of defects. Furthermore, when the corrugation depth is large, completely removing the rail surface corrugations is extremely difficult. Summary of the Invention
[0008] To address the above problems, this invention employs engineering methods, summarizing and generalizing routine track maintenance and rail surface defect management, and proposes a comprehensive management method for corrugation defects on small-radius curves of heavy-haul railways, effectively suppressing the initiation and development of rail surface corrugation.
[0009] The present invention provides a comprehensive treatment method for corrugation defects on small-radius curves in heavy-haul railways, which is achieved through the following steps:
[0010] Step 1: Inspect the condition of the curve with corrugation defects, including ballast bed compaction, rail head whitening, and the condition of the under-rail rubber pads.
[0011] Step 2: Analyze the inspection results and take appropriate action.
[0012] Step 3: Detect the distribution and depth of rail corrugation, and collect rail profile data; by detecting the distribution and depth of rail corrugation, it can be determined whether the curve has local corrugation or corrugation over a large area. By measuring the corrugation depth, the average value and maximum value of the corrugation depth can be obtained.
[0013] Step 4: Establish a real-parameter vehicle-track coupled dynamics model, and obtain the grinding target profile through wheel-rail contact geometry and wheel-rail creep.
[0014] Step 5: Develop a treatment plan for surface corrugation on curved rails, including:
[0015] Option 1: If there are corrugations with a depth of 0.5mm or less in a local area of the curve, use a large grinding machine to remove the rail surface corrugations, and at the same time grind the rail to the target profile.
[0016] Option 2: If there are severe corrugations with a depth of more than 0.5 mm in some parts of the curve, the extreme points should be removed first by using a small grinding machine to grind the corrugations to a depth of less than 0.5 mm, and then the rail surface corrugations should be removed by using a large grinding machine, while grinding the rail to the target profile.
[0017] Option 3: If the curve has a large area of corrugation defects with an average corrugation depth of less than 0.5mm, use a large machine to grind away the rail surface corrugation, and at the same time grind the rail profile to the target profile.
[0018] Option 4: If the curve has severe corrugation defects with an average corrugation depth of 0.5 mm or more over a large area, the rail top corrugation must first be removed by rail milling, and then the rail must be ground to the target profile to improve the wheel-rail relationship.
[0019] Step 6: Arrange rail side lubrication and rail top coating equipment according to the corrugation curve, and adjust the rail surface friction coefficient so that the rail top friction coefficient reaches μ=0.3-0.4 and the rail side friction coefficient reaches μ<0.2.
[0020] The advantages of this invention are:
[0021] 1. The present invention provides a comprehensive treatment method for corrugation defects on small-radius curves of heavy-haul railways. Compared with previous corrugation defect treatment methods, this method comprehensively considers various factors that cause and develop rail corrugation, and addresses rail corrugation defects in a targeted manner.
[0022] 2. The comprehensive treatment method for corrugation defects on small-radius curves of heavy-haul railways of the present invention is applicable to the treatment of corrugation defects caused by multiple factors, and has a more obvious effect on inhibiting the development of corrugation compared with previous treatment methods.
[0023] 3. The comprehensive treatment method for corrugation defects on small-radius curves of heavy-haul railways of this invention has been comprehensively optimized based on previous treatment methods. It avoids the shortcomings of previous methods that only treat the symptoms and not the root cause. Multiple grinding or milling can quickly increase the vertical wear of the rail and accelerate the wear of the rail to the limit. Using this method can effectively alleviate the development of rail corrugation defects, extend the grinding or milling cycle of the rail, slow down the wear rate of the rail, and thus extend the service life of the rail.
[0024] 4. The comprehensive treatment method for corrugation defects on small-radius curves of heavy-haul railways of the present invention can keep the line in good condition for a longer period of time after maintenance using this method, effectively reduce the impact of rail corrugation defects on the overall condition of the line, and save line maintenance costs to a certain extent. Attached Figure Description
[0025] Figure 1 This is an overall flowchart of the comprehensive treatment method for corrugation defects on small-radius curves of heavy-haul railways according to the present invention;
[0026] Figure 2a The corrugation distribution 10 days after grinding a 400m radius curve of a heavy-haul railway using thermoplastic pads.
[0027] Figure 2b Corrugation distribution 30 days after grinding when thermoplastic pads are used on a 400m radius curve of a heavy-haul railway.
[0028] Figure 2c The corrugation distribution 10 days after grinding a 400m radius curve of a heavy-haul railway using Gästner rubber pads.
[0029] Figure 2d Corrugation distribution 30 days after grinding for a 400m radius curve of a heavy-haul railway using Gschner rubber pads.
[0030] Figure 3 This is a diagram showing the distribution of rail corrugation and the measurement of corrugation depth.
[0031] Figure 4 The curve shows a comparison of the wear on the side of the stock before and after lubrication. Detailed Implementation
[0032] The present invention will now be described in further detail.
[0033] This invention relates to a comprehensive treatment method for corrugation defects on small-radius curves in heavy-haul railways, such as... Figure 1 As shown, this is achieved through the following steps:
[0034] Step 1: Check the status of the corrugated curve circuit.
[0035] Curves with corrugation defects often experience track bed hardening due to significant vehicle vibration, leading to crushing or loss of rail pads. Before addressing these defects, the track condition must be inspected and recorded in detail, including whether the track bed is hardened, whether there is severe whitening of the rail sleepers, and whether there is crushing, slippage, or loss of rail pads.
[0036] Step 2: Analyze the line status check results and take appropriate action.
[0037] Analyzing the results of the track condition inspection, if the ballast bed is compacted or the rail sleepers are severely whitened, cleaning and tamping are required before removing the surface corrugations of the rails to restore track elasticity. If high-elasticity rubber pads are used under the rails, crushed pads need to be replaced, and protruding or missing pads need to be repositioned. If ordinary rubber pads are used under the rails, it is recommended to replace them with high-elasticity pads, such as Gschna polyurethane pads. Compared with thermoplastic pads, these have lower static stiffness, higher elasticity, less permanent deformation, and better vibration damping performance. See Table 1 for a detailed comparison.
[0038] Table 1 Comparison of polyurethane pads and thermoplastic pads
[0039]
[0040] By comparison Figures 2a-2dIt can be seen that when using thermoplastic pads, the wear exceedance rate for wavelengths of 30-100mm was 31.4% 10 days after polishing, and for wavelengths of 100-300mm it was 25.5%; after 30 days after polishing, the wear exceedance rate for wavelengths of 30-100mm was 40.0%, and for wavelengths of 100-300mm it was 32.9%. When using Gäsner polyurethane pads, the wear exceedance rate for wavelengths of 30-100mm was 0.4% 10 days after polishing, and for wavelengths of 100-300mm it was 4.2%; after 30 days after polishing, the wear exceedance rate for wavelengths of 30-100mm was 10.6%, and for wavelengths of 100-300mm it was 24.5%, indicating a significant slowdown in the wear rate.
[0041] Step 3: Detect the distribution and depth of rail corrugation, and collect rail profile data.
[0042] The distribution and depth of rail corrugation are detected using a rail corrugation measuring instrument. Figure 3 As shown, the profiles of the upper and lower rails are measured at positions along the curve. By detecting the distribution and depth of rail corrugation, it can be determined whether corrugation exists locally or throughout the entire curve. The average and maximum corrugation depths can be obtained by measuring the corrugation depth.
[0043] Step 4: Establish a real-parameter (actual parameters of the running vehicle) vehicle-track coupled dynamics model. Through key parameters such as wheel-rail contact geometry and wheel-rail creep, design the grinding target profile.
[0044] A real-parameter vehicle-track coupled dynamic model was established based on railway rail and track parameters and information on major operating vehicles. Through simulation calculations, dynamic response indicators such as derailment coefficient, wheel-rail lateral force, wear index, wheelset angle of attack, wheel-rail creep rate, and wheel-rail contact stress were obtained. These dynamic response indicators were compared with relevant standards to calculate the optimal grinding target profile.
[0045] Step 5: Develop a treatment plan for surface corrugation on curved rails.
[0046] Based on the corrugation detection results, the following treatment plan for surface corrugation of curved rails is formulated.
[0047] Option 1: If there are corrugations with a depth of 0.5mm or less in a local area of the curve, use a large grinding machine to remove the rail surface corrugations, and at the same time grind the rail to the target profile.
[0048] Option 2: If severe corrugation defects with a depth exceeding 0.5mm exist in a localized area of the curve, the extreme points should first be removed using a small grinding machine to reduce the corrugation depth to below 0.5mm. Then, a large grinding machine should be used to remove the rail surface corrugation while simultaneously grinding the rail to the target profile. During small-machine grinding, the actual measured rail profile before grinding should be used as the target profile to maintain the profile as unchanged as possible when removing localized corrugations, thus avoiding localized profile differences after large-machine grinding.
[0049] Option 3: If the curve has a large area of corrugation defects with an average corrugation depth of less than 0.5mm, use a large machine to grind away the rail surface corrugation, and at the same time grind the rail profile to the target profile.
[0050] Option 4: If the curve has severe corrugation defects with an average corrugation depth of 0.5 mm or more over a large area, the rail top corrugation must first be removed by rail milling, and then the rail must be ground to the target profile to improve the wheel-rail relationship.
[0051] Step 6: After removing the corrugation on the curved rail surface using the method in Step 5, arrange rail side lubrication and rail top coating equipment for the corrugated curve and adjust the rail surface friction coefficient.
[0052] As wear progresses, railside wear gradually develops on the rail sides of small-radius curves in heavy-haul railways. This railside wear increases lateral wheel-rail forces and vehicle lateral vibration. Furthermore, rail wear alters the rail profile, worsening the wheel-rail relationship. To address this issue, lubrication and coating equipment is installed on the curves to adjust the rail surface friction coefficient, achieving a rail top friction coefficient of μ = 0.3-0.4 and a rail side friction coefficient of μ < 0.2. This lubrication and coating equipment consists of a lubrication unit and a coating unit. The lubrication unit adjusts the rail side friction coefficient, while the coating unit adjusts the rail top friction coefficient, reducing rail wear, mitigating rail profile changes, and maintaining a good wheel-rail relationship. After the lubrication and coating equipment is installed on the line, the sensing device automatically sprays coating when a vehicle passes. The lubrication unit is typically located on the straight section before the curve, and the range of rail side lubrication is controlled by adjusting the amount of oil sprayed. The comparison of rail side wear before and after lubrication is shown in the figure. Figure 4 As shown, the coating device can be placed at relatively flexible locations, either on the straight section or the curved section before the curve. The lubricating grease is carried onto the curve by the wheels. The coating range of the coating device is about 400m, and additional coating equipment can be added as appropriate according to the length of the curve.
Claims
1. A comprehensive treatment method for corrugation defects on small-radius curves of heavy-haul railways, characterized in that: This can be achieved through the following steps: Step 1: Inspect the condition of the curves with corrugation defects, including ballast bed compaction, rail head whitening, and the condition of the under-rail rubber pads; Step 2: Analyze the inspection results and take appropriate action; Step 3: Detect the distribution and depth of rail corrugation, and collect rail profile data; by detecting the distribution and depth of rail corrugation, it can be determined whether the curve has local corrugation or large-scale corrugation. By measuring the corrugation depth, the average value and maximum value of the corrugation depth can be obtained. Step 4: Establish a real-parameter vehicle-track coupled dynamics model, and obtain the grinding target profile through wheel-rail contact geometry and wheel-rail creep; Step 5: Develop a treatment plan for surface corrugation on curved rails, including: Option 1: If there are corrugations with a depth of 0.5mm or less in a local area of the curve, use a large grinding machine to remove the rail surface corrugations, and at the same time grind the rail to the target profile. Option 2: If there are severe corrugations with a depth of more than 0.5 mm in some parts of the curve, the extreme points should be removed first by using a small grinding machine to grind the corrugations to a depth of less than 0.5 mm, and then the rail surface corrugations should be removed by using a large grinding machine, while grinding the rail to the target profile. Option 3: If the curve has a large area of corrugation defects with an average corrugation depth of less than 0.5mm, use a large machine to grind away the rail surface corrugation, and at the same time grind the rail profile to the target profile. Option 4: If the curve has severe corrugation defects with an average corrugation depth of 0.5mm or more over a large area, the rail top corrugation must first be removed by rail milling, and then the rail must be ground to the target profile to improve the wheel-rail relationship. Step 6: Arrange rail side lubrication and rail top coating equipment according to the corrugation curve, and adjust the rail surface friction coefficient so that the rail top friction coefficient reaches μ=0.3-0.4 and the rail side friction coefficient reaches μ<0.
2.
2. The comprehensive treatment method for corrugation defects on small-radius curves of heavy-haul railways as described in claim 1, characterized in that: In step 2, if the track bed is compacted or the sleepers are severely whitish, it is necessary to clean, sift, and tamp the track to restore its elasticity. If high-elasticity rubber pads are used under the rails, crushed pads must be replaced and any loose or missing pads must be repositioned. If ordinary rubber pads are used under the rails, they must be replaced with high-elasticity rubber pads.
3. The comprehensive treatment method for corrugation defects on small-radius curves of heavy-haul railways as described in claim 2, characterized in that: The high-elasticity rubber pad uses Gschna polyurethane padding.
4. The comprehensive treatment method for corrugation defects on small-radius curves of heavy-haul railways as described in claim 1, characterized in that: In step 3, the profiles of the upper and lower rails are measured at the positions in the curve.
5. The comprehensive treatment method for corrugation defects on small-radius curves of heavy-haul railways as described in claim 1, characterized in that: In step 6, the rail side lubrication equipment is arranged on the straight section before the curve, and the range of rail side lubrication is controlled by adjusting the amount of oil sprayed; the rail top coating equipment is arranged on the straight section before the curve or on the curved section, and the lubricating grease is carried onto the curve by the wheels. The coating range of the coating device is about 400m, and the coating equipment is appropriately added according to the length of the curve.