A personalized curve rail milling and grinding scheme design method

Abstract

The application discloses a personalized curve rail milling and grinding scheme design method, which comprises the following steps: firstly, detecting the rail state of a curve section; then, judging single rail milling and grinding or upper and lower rail milling and grinding according to the rail profile and disease condition; aligning the measured profiles of the same curve, and selecting the profile with the median deviation value as a representative profile; when milling and grinding the lower rail, aligning the first contact point of the representative profile and the cutter disc profile, calculating the distance between the center of the cutter disc profile and the center of the profile before milling and grinding, and combining the disease depth to obtain the designed milling and grinding amount; when milling and grinding the upper rail, aligning the measured upper rail profile and the designed profile according to the side grinding mode, aligning the center of the cutter disc profile with the rail top center of the designed profile, and making the cutter disc contact with the highest point of the measured profile, and calculating the distance between the center of the cutter disc profile and the rail top center of the designed profile, which is the milling and grinding depth; determining the milling and grinding amount of the milling cutter in single feeding through the relationship between the milling and grinding amount and the feeding amount, and obtaining the cutter disc transverse displacement through the calculation of the rail side grinding amount; and finally, calculating the feeding times of the two milling cutters on one side.

Description

Technical Field

[0001] This invention belongs to the field of rail milling technology and relates to a design method for a personalized curved rail milling scheme. Background Technology

[0002] As a crucial piece of railway track equipment, steel rails bear the load of trains. Influenced by a combination of factors including track condition, line conditions, and rolling stock, they gradually deteriorate during service, developing defects such as spalling, wavy wear, edge thickening, and abnormal wear. With the annual increase in railway freight transport, rail surface defects are becoming increasingly severe, especially on heavy-haul railways, where serious spalling and wavy wear are frequently observed. If rail defects are not addressed promptly and effectively, their development will accelerate, significantly shortening the rail's service life and even jeopardizing traffic safety.

[0003] Rail milling is a common maintenance method for removing rail defects. Using a milling cutter on a rail milling machine, the rail is milled to effectively remove fatigue damage, corrugation, and spalling. However, current rail milling operations in China rely entirely on experience, lacking scientific design based on the actual rail profile and defects. This makes it difficult to determine the appropriate milling amount. Insufficient milling at the rail top when rail profile deviations are large, or excessive milling when defects are severe, shortens rail lifespan. Furthermore, it fails to specifically repair the rail profile and maintain a good wheel-rail relationship. Summary of the Invention

[0004] To address the above issues and accurately determine the milling amount under different track conditions and different defects, thus providing effective guidance for milling operations and eliminating defects without over-milling, this invention proposes a rail milling scheme design method based on a rail milling vehicle. Before milling, by measuring the rail profile and rail surface defects and combining it with certain data processing algorithms, a rail milling scheme for the corresponding working conditions can be accurately designed.

[0005] This invention proposes a design method for a personalized curved rail milling scheme, which is achieved through the following steps:

[0006] A method for designing a personalized milling scheme for curved rails, characterized by the following specific steps:

[0007] Step 1: Rail condition inspection, obtain rail parameter information, including rail profile and rail surface defect detection.

[0008] Step 2: Determine whether the rail to be milled is a single strand or both upper and lower strands milled simultaneously.

[0009] Step 3: Based on the judgment result of Step 2, align the corresponding rail profile with the design profile, and select the profile with the middle deviation as the representative profile.

[0010] Step 4: Calculate the milling amount of the curved rail.

[0011] A. The calculation method for the milling amount of the rail under the curve is as follows:

[0012] a1. Align the center points of the cutter head profile and the representative profile on the same vertical line. When the cutter head profile and the representative profile contact each other at the first contact point A, calculate the vertical distance between the center points of the representative profile and the cutter head profile, i.e., the vertical distance d between the center point B of the cutter head and the center point C of the profile before milling. f ;

[0013] a2, using formula d max =d h +d f +d j Calculate the milling amount of the lower rail under the curve, where d max The required maximum milling amount; d h Average depth of track surface defects d j For experience value; d f The profile deviation obtained in a1;

[0014] B. The calculation method for the milling amount of the rail on the curve is as follows:

[0015] b1. Align the representative profile and the design profile using the side-grinding alignment method. The center point of the cutter head profile should be on the normal line of the center point c of the design profile. When the cutter head profile and the representative profile contact at the first contact point a, calculate the vertical distance D between the center of the cutter head profile and the center point c of the guide rail of the design profile. f ;

[0016] b2. Without a pulsator, D f This refers to the milling amount H; when corrugation defects exist, if the corrugation depth is less than D... f D f This refers to the milling amount H. If the corrugation depth is greater than D... f The milling amount H is equal to the corrugation depth.

[0017] Step 5: Calculate the rail side wear amount and determine the lateral movement of the upper cutterhead.

[0018] Step 6: Calibrate the relationship between the number of feeds of the milling lathe and the milling amount, and determine the milling amount per feed.

[0019] Step 7: Calculate the number of feeds.

[0020] Step 8: Determine the milling scheme.

[0021] The advantages of this invention are:

[0022] 1. The present invention provides a personalized curved rail milling scheme design method, which innovatively proposes a method for calculating the amount of rail milling. This transforms the previous experience-based milling into a personalized milling with traceable patterns and methods, making the milling operation more precise, preventing excessive rail milling caused by relying solely on experience, and accelerating the vertical grinding to the limit.

[0023] 2. The personalized curved rail milling scheme design method of the present invention is easy to operate. By inputting the collected data on the rail profile and surface defects of the milling section, the number of cuts for each milling cutter can be calculated.

[0024] 3. The personalized curved rail milling scheme design method of the present invention has wide application and is suitable for various types of milling machines. The invention provides a calculation method for the milling amount of each feed, which can be applied to milling machines of different models.

[0025] 4. The personalized curved rail milling scheme design method of the present invention is easy to promote and use. The invention provides a complete rail milling scheme design process, and the milling scheme design can be completed by following the process. Attached Figure Description

[0026] Figure 1 This is an overall flowchart of the design method for a personalized curved rail milling scheme according to the present invention.

[0027] Figure 2 This is a schematic diagram of the profile measurement points.

[0028] Figure 3a This is an example diagram showing the alignment of the measured profile of a rail on a curve with the designed profile.

[0029] Figure 3b This is an example diagram showing the alignment of the measured profile of the rail under the curve with the designed profile.

[0030] Figure 4a This is a schematic diagram showing the positional relationship between the cutterhead and the rail profile on the curve.

[0031] Figure 4b This is a schematic diagram showing the positional relationship between the cutterhead and the lower rail profile of the curve. Detailed Implementation

[0032] The present invention will now be described in further detail with reference to the accompanying drawings.

[0033] This invention provides a design method for a personalized curved rail milling scheme, such as... Figure 1 As shown, this is achieved through the following steps:

[0034] Step 1: Obtain rail parameter information through rail condition detection.

[0035] Rail condition inspection includes rail profile inspection, rail corrugation inspection, and rail surface fatigue spalling inspection, which respectively obtain information on rail profile, surface defects, and corrugation conditions. The specific methods are as follows:

[0036] A. Rail profile inspection

[0037] The profiles of the upper and lower rails in the milled curve section were measured, including the profiles at three points: the curve's transition point, the middle of the curve, and the transition point of the curve. Specific measurement locations are as follows: Figure 2 As shown.

[0038] B. Rail corrugation inspection

[0039] For milled curved sections, a rail corrugation trolley or rail profiler is used to detect corrugation defects on the rail surface. Based on the detection data, it is determined whether corrugation exists in the milled section. If corrugation exists, the maximum corrugation depth is determined based on the detection data.

[0040] C. Detection of fatigue spalling on rail surfaces

[0041] When detecting fatigue spalling depth on the rail surface of milled curved sections, a depth gauge is used to measure the locations on the rail surface where large areas of spalling are visually observed, and the average value is taken. The number of measurement points is recorded as n, and the spalling depth at each point is recorded as a. i Average drop depth Where i = 1, 2, 3, ..., n.

[0042] Step 2: Determine whether to mill a single strand or mill both the upper and lower strands simultaneously.

[0043] If the lower strand of the curve does not have severe spalling or undulation defects, milling is not required. If the upper strand of the curve does not have undulation defects and the maximum deviation between the upper strand profile and the milling target profile is less than 0.2 mm, milling is not required.

[0044] Step 3: Align the upper and lower rail profiles of the milled curve according to their respective suitable methods, and select representative profiles.

[0045] 1. Align the lower profile obtained from step 1 at the three points of the curve's gentle curve, the middle of the curve, and the gentle curve's transition with the designed profile using the inner alignment method, such as... Figure 3a As shown.

[0046] 2. Align the profiles at the three points (curve transition, mid-curve, and curve transition) obtained in step 1 with the designed profile using the side grinding alignment method, such as... Figure 3b As shown.

[0047] 3. After alignment, select the silhouette with the central deviation as the representative silhouette.

[0048] Step 4: Calculate the milling amount of the curved rail.

[0049] A. If the lower rail of the curve needs to be milled, the calculation method for the milling amount is as follows:

[0050] a1. Calculate the vertical distance between the center point of the profile represented by the lower curve and the center point of the cutter head profile.

[0051] Align the center points of the cutter head profile and the representative profile on the same vertical line. When the cutter head profile and the representative profile contact each other at the first contact point A (the initial contact point between the cutter head profile and the representative profile), calculate the vertical distance between the center points of the representative profile and the cutter head profile, that is, the vertical distance d between the center point B of the cutter head and the center point C of the profile before milling. f ,like Figure 4a As shown, d f This refers to the profile deviation caused by rail surface concavity. If concavity exists on the rail surface, the profile deviation caused by concavity must be removed during milling before milling to the top of the rail. If there is no concavity on the rail surface, the center point of the cutter head approximately coincides with the center line of the profile before milling. f It is 0.

[0052] a2. Calculate the amount of milling on the lower rail of the curve.

[0053] The formula for calculating the milling amount of the lower rail under the curve is d. max =d h +d f +d j In the formula d max The required maximum milling amount; d h The depth of rail surface defects is taken as the average value of the depths of corrugation and spalling defects. d j This is an empirical value of 0.3mm, ensuring that defects on the rail surface can be effectively removed after milling.

[0054] B. If the rails on the curve need to be milled, the milling amount is calculated as follows:

[0055] b1. Align the representative profile and the design profile using the side-grinding alignment method. The center point of the cutter head profile should be on the normal line of the center point c of the design profile. When the cutter head profile and the representative profile contact at the first contact point a, calculate the vertical distance D between the center of the cutter head profile and the center point c of the guide rail of the design profile. f The milling depth is obtained by combining the condition of the disease.

[0056] The vertical distance D between the above-mentioned cutter head profile and the center point c of the designed profile. f Without a ripple, D f This refers to the milling amount H; when corrugation defects exist, if the corrugation depth is less than D... f D f This refers to the milling amount H. If the corrugation depth is greater than D... f The milling amount H is equal to the corrugation depth.

[0057] Step 5: Calculate the rail side wear amount and determine the lateral movement of the upper cutterhead;

[0058] After aligning the representative profile with the standard rail profile, calculate the horizontal difference 16mm below the rail apex, which is the rail side grinding amount; determine the lateral movement of the upper cutter head, which is slightly less than the side grinding amount to prevent scratching the rail side during milling. The side grinding amount here is rounded down to get the cutter head lateral movement amount.

[0059] Step 6: Calibrate the relationship between the number of feeds of the milling lathe and the milling depth;

[0060] By calibrating the relationship between the milling lathe feed rate and the milling depth, the milling depth per single feed is determined. The milling lathe feed rate h, the milling depth d, and the milling depth per single feed are defined as m; that is, the relationship between the three is h = d × m. Since mechanical vibration introduces some error, multiple milling experiments can be conducted to determine multiple sets of m values. The average value, rounded to one decimal place, is then taken as the milling depth per single feed. As shown in Table 3, the milling depth m per single feed in the three milling experiments were 0.099, 0.093, and 0.101, respectively. The average value, rounded to one decimal place, is 0.1 mm.

[0061] Table 3. Analysis of the relationship between feed rate and milling amount

[0062]

[0063] Step 7: Calculate the number of feeds

[0064] The milling machine has two end mills on one side, and each end mill has d feeds k = d. max / m / 2, where k is the number of feeds for each milling cutter, rounded down. For example, the number of feeds for milling on the upper section of the K168+500 curve is k1=4, k2=3; the number of feeds for milling on the lower section of the curve is k1=10, k2=9.

[0065] Step 8: Determine the milling plan. The milling plan is a detailed table of parameters for the milling operation, including the milling curve radius, total length, corrugation depth, chipping depth, upper cutter head lateral movement, and the number of feeds for the two milling cutters on the left and right sides of the milling machine. This facilitates the milling operation. During the milling operation, after starting the milling machine, tool setting is performed first. After tool setting is completed, the corresponding number of feeds is entered sequentially according to the milling plan.

Claims

1. A design method for a personalized curved rail milling scheme, characterized in that: The specific steps are as follows: Step 1: Rail condition inspection, obtaining rail parameter information, including rail profile and rail surface defect detection; Step 2: Determine whether the rail to be milled is a single strand or both upper and lower strands milled simultaneously; Step 3: Based on the judgment result of Step 2, align the corresponding rail profile with the design profile, and select the profile with the middle deviation as the representative profile; Step 4: Calculate the milling amount for the curved rail; A. The calculation method for the milling amount of the rail under the curve is as follows: a1. Align the center points of the cutter head profile and the representative profile on the same vertical line. When the cutter head profile and the representative profile contact each other at the first contact point A, calculate the vertical distance between the center points of the representative profile and the cutter head profile, i.e., the vertical distance d between the center point B of the cutter head and the center point C of the profile before milling. f ; a2, using formula d max = d h +d f +d j Calculate the milling amount of the lower rail under the curve, where d max The required maximum milling amount; d h Average depth of track surface defects ;d j For experience value; d f The profile deviation obtained in a1; B. The calculation method for the milling amount of the rail on the curve is as follows: b1. Align the representative profile and the design profile using the side-grinding alignment method. The center point of the cutter head profile should be on the normal line of the center point c of the design profile. When the cutter head profile and the representative profile contact at the first contact point a, calculate the vertical distance D between the center of the cutter head profile and the center point c of the guide rail of the design profile. f ; b2. Without a pulsator, D f This refers to the milling amount H; when corrugation defects exist, if the corrugation depth is less than D... f D f This refers to the milling amount H. If the corrugation depth is greater than D... f The milling amount H is equal to the corrugation depth; Step 5: Calculate the rail side wear amount and determine the lateral movement of the upper cutterhead; Step 6: Calibrate the relationship between the number of feeds of the milling lathe and the milling amount, and determine the milling amount per feed; Step 7: Calculate the number of feeds; Step 8: Determine the milling scheme.

2. The personalized curved rail milling scheme design method as described in claim 1, characterized in that: In step 1, the upper and lower rails of the milled section are inspected, the profiles of the gentle curve, the middle curve, and the gentle curve are measured, and the location of severe corrugation on the curve is detected. The depth of the broken pieces is measured and the average value is taken.

3. The personalized curved rail milling scheme design method as described in claim 1, characterized in that: In step 2, if there are no severe chipping or ripple defects on the lower strand of the curve, then milling is not required; if there are no ripple defects on the upper strand of the curve and the maximum deviation of the upper strand profile is less than 0.2 mm, then milling is not required.

4. The personalized curved rail milling scheme design method as described in claim 1, characterized in that: In step 3, the upper rail profile is aligned by aligning it with the design profile using the side grinding alignment method; the lower rail profile is aligned by aligning it with the design profile using the inner side alignment method.

5. The personalized curved rail milling scheme design method as described in claim 1, characterized in that: In step 5, the method for determining the lateral movement of the upper cutter head is as follows: Align the representative profile with the standard rail profile, calculate the horizontal difference 16mm downward from the top of the rail, which is the rail side wear amount, and round down to the cutter head lateral movement amount.

6. The personalized curved rail milling scheme design method as described in claim 1, characterized in that: The method for calculating the number of feeds in step 7 is as follows: For each milling cutter on both sides of the milling machine, the number of feeds is k=d. max / m / 2, where k is the number of feeds per milling cutter, rounded down; m is the milling depth per feed; d max This represents the maximum milling amount.

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