High-speed turnout front steel rail grinding profile design method

Abstract

The invention discloses a grinding profile design method for a front steel rail of a high-speed turnout. The method comprises the steps that firstly, the profile and diseases of the front steel rail of the high-speed turnout are measured and collected; discretization processing is conducted on the measured steel rail profile, and according to the deviation obtained through calculation, the steel rail polishing design profile under various kinds of abrasion is generated according to an optimization fitting method and a polyline polynomial overall fitting method. Turnout models are established on the basis of different designed steel rail polishing profiles, a vehicle-turnout system coupling dynamics analysis model is established on the basis of the turnout models, and the safety of the designed profiles is verified. According to the field actual measurement profile, the profile is compared with the designed polishing profile, the disease condition is considered, and the appropriate steel rail polishing profile is selected according to the minimum polishing amount principle. By means of the method, different polishing design profiles can be generated according to different lines, different turnouts and different abrasion and damage conditions, and the designed profiles meet the dynamic performance standard of national railway groups.

Description

Technical Field

[0001] The invention belongs to the field of railway rail profile design, and in particular relates to a method for designing a rail grinding profile at a position before a high-speed turnout. Background Art

[0002] The continuous extension of railway operating mileage is changing the way Chinese people travel and live, and people's requirements for railway speed and operating efficiency are getting higher and higher. As a connection and conversion device between train tracks, turnouts are important components of the entire track system. Once they fail or are in poor service, they will directly affect driving efficiency. High-speed turnout rails are damaged by many diseases, which has always been a difficult point in the maintenance of high-speed railway lines. In particular, the current problems of severe side wear and frequent surface diseases such as fish scale damage on the front rails of turnouts have become a problem that plagues the engineering department.

[0003] Although there are already design profiles for turnout rails, the design profiles are based on the overall state of the turnout and are designed for the turnout as a whole. Not much consideration is given to the damage and disease of the rails in front of the high-speed turnout, which can easily lead to excessive grinding of the rails, reduce the service life of the rails, and increase the maintenance workload and difficulty of repair.

[0004] Based on the above problems, a method for designing the grinding profile of the rail before the turnout of a high-speed turnout is now needed to solve the above problems. Summary of the invention

[0005] The present invention aims at the problems that the front end rails of turnouts have severe side wear, frequent surface diseases such as fish scale damage, etc., and based on the fact that the current turnout profile design does not take into account the damage and diseases of the rails in front of high-speed turnouts, resulting in excessive rail grinding, reduced rail service life, increased maintenance workload and repair difficulty, a method for designing the grinding profile of the rails in front of high-speed turnouts is provided.

[0006] The method for designing the grinding profile of the rail before the high-speed turnout of the present invention comprises the following steps:

[0007] Step 1: Measure and collect the rail profile before the high-speed turnout.

[0008] Step 2: Measure and collect the rail defects before the high-speed turnout.

[0009] Step 3: Divide the rail profile into six equal areas horizontally, determine the upper and lower limits of the wear of the profile curve in each area, perform spectrum analysis on the wear, and calculate the deviation of the profile curve in each area from the standard profile curve.

[0010] Step 4: Discretize the rail profile, and divide the upper and lower wear limits of the profile curve in each area into N intervals longitudinally; use the arithmetic mean fitting method to calculate the average coordinates of each point on the rail profile curve in each interval in turn as the representative point in each interval; further, fit through multi-segment function curves to generate rail grinding design profiles in 6 areas respectively.

[0011] Step 5: Use the interpolation fitting method to fit the rail grinding design profile in each area obtained in step S4 to obtain the overall rail grinding design profile.

[0012] Step 6: Establish turnout models based on different designed rail grinding profiles, and construct a vehicle-turnout system coupling dynamics analysis model based on the turnout model to verify the safety of the rail grinding design profile obtained in step S4.

[0013] Step 7: Compare the actual measured profile on site with the designed grinding profile, consider the defect situation, and select the appropriate rail grinding profile based on the principle of minimum grinding amount.

[0014] The advantages of the present invention are:

[0015] 1. The method for designing the grinding profile of the rail in front of a high-speed turnout of the present invention can generate different grinding design profiles for different lines, different turnouts, different wear and damage conditions.

[0016] 2. The method for designing the grinding profile of the rail in front of a high-speed turnout of the present invention can achieve a profile design that meets the dynamic performance standards of the China Railway Corporation through simulation calculation.

[0017] 3. The rail grinding profile obtained by the high-speed turnout front rail grinding profile design method of the present invention can be directly applied at the grinding site without recalculation, which is convenient and quick.

[0018] 4. The design method for grinding the profile of the rail in front of a high-speed turnout of the present invention can be completed by self-compiled software, so that the design method has better versatility. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a flow chart of the method for designing the profile of the rail grinding before the turnout of a high-speed turnout according to the present invention;

[0020] Figure 2 Schematic diagram of rail profile interval division method. DETAILED DESCRIPTION

[0021] The present invention will be further described in detail below in conjunction with the accompanying drawings.

[0022] The method for designing the profile of the rail grinding before the high-speed turnout of the present invention is as follows: Figure 1The specific steps are as follows:

[0023] S1: Measure and collect the rail profile before the high-speed turnout.

[0024] Use the Miniprof rail profiler to collect the left and right rail profiles of the 1st to 4th sleepers in front of the tip of the turnout rail that needs to be polished, as well as the left and right rail profiles of the 5th, 10th and 20th sleepers in front of the turnout.

[0025] S2: Measure and collect the rail defects before high-speed turnouts.

[0026] The eddy current flaw detector and depth meter are used to collect the defects of the left and right rails at the sleeper position in step S1, and record whether there are defects such as fish scale damage and block drop, and record the depth of fish scale damage and block drop respectively.

[0027] S3: Calculate the deviation of rail profile at different positions.

[0028] The rail profiles measured in step S1 are aligned with the standard cn60 rail profiles, and statistical analysis is performed on the measured rail profiles. Specifically, the rail profiles are divided into 6 equal areas horizontally, such as Figure 2 As shown, the upper and lower limits of the wear of the profile curve in each area are determined respectively, the wear is subjected to spectrum analysis, and the deviation of the profile curve in each area from the standard profile curve is calculated respectively.

[0029] S4: Generate rail grinding design profile based on deviation calculation.

[0030] (1) Discretize the rail profile collected in step S1

[0031] (2) The wear upper and lower limit intervals of the profile curve in each area are divided into N intervals longitudinally;

[0032] (3) Using the arithmetic mean fitting method, the average coordinates of each point on the rail profile curve in each region N intervals are calculated in turn as the coordinates of the representative point in interval j (x j代 ,y j代 ):

[0033]

[0034] In formula (1), z is the total number of points on the rail profile curve in interval j; (x ij ,y ij ) is the coordinate of point i on the rail profile curve in interval j.

[0035] (4) A multi-segment function curve is used for fitting to generate rail grinding design profiles in six areas. The specific method is as follows:

[0036] Assume the fitting function G(x) is an n-order polynomial:

[0037]

[0038] Where β is the curve fitting coefficient; n is the total number of representative points in the region.

[0039] At the same time, let the sum of squares of deviations between the fitting function and the true value be:

[0040]

[0041] The coefficient β in equation (2) is determined so that the sum of squared deviations δ is minimized.

[0042] S5: Using an interpolation fitting method to fit the rail grinding design profile in each area obtained in step S4, to obtain the overall rail grinding design profile.

[0043] When the number of data points of a segmented curve is limited, the third-order polynomial fitting can better meet the accuracy requirements of the fitting curve. The third-order least squares polynomial fitting is performed on the data in each segment, and the data is substituted into the following formula to obtain the fitting coefficient of each segment of the curve.

[0044] Since it is difficult to ensure that the rail profile curves of each region are continuous and differentiable at the intersection points in the rail profile curve obtained by third-order polynomial fitting, the interpolation fitting method is used to connect the rail profile curves of each region. Since the rail profile curve is a continuous smooth curve, constraints are added to each connection interpolation curve function so that the connection interpolation curve T of the rail profile curves of adjacent regions is i (x) and the adjacent area rail profile curve function at the connection point (x ik ,f(x ik )) and (x (i+1)(k+1) ,f(x (i+1)(k+1) )) have the same function values:

[0045]

[0046] In the formula, x ik is the i-th connection point of the k-th rail profile curve; x (i+1)(k+1) It is the i+1th connection point on the k+1th rail profile curve.

[0047] At the same time, ensure that the interpolation connection curve and each piecewise function (x ik ,f(x ik )) and (x (i+1)(k+1) ,f(x (i+1)(k+1) )) are equal, that is:

[0048]

[0049] At the same time, the purpose of the interpolation connection curve is to ensure that the position of the segmented point of the rail grinding design profile is continuous and differentiable during the design process. Therefore, the interpolation connection curve adopts third-order interpolation to meet the requirements, that is:

[0050] T1(x)=e1x 3 +e2x 2 +e3x+e4

[0051] In the formula, e1, e2, e3, e4 are coefficients, and x is the variable.

[0052] In step S3, the upper and lower limits of wear of the 10 profile curves in each region are determined, and 10 rail grinding design profiles can be obtained by the method described in step S4.

[0053] S6. Based on different designed rail grinding profiles, turnout models are established respectively, and a vehicle-turnout system coupling dynamic analysis model is constructed based on the turnout model to verify the safety of the 10 rail grinding design profiles obtained in step S4. The verification method is based on the standard of GBT 5599-2019 "Specifications for Evaluation and Test Identification of Locomotive and Vehicle Dynamic Performance", and the vehicle running stability, vehicle vibration acceleration, etc. are evaluated through simulation. If the rail design profile does not meet the verification, it will be discarded, and after modifying the wear parameters in step S3, step S4 is repeated to generate a new design profile.

[0054] S7. Compare the measured profile on site with the designed grinding profile, consider the defect situation, and select the appropriate rail grinding profile based on the principle of minimum grinding amount.

[0055] The minimum grinding amount principle is: the worn rail f of a certain operating line worn60 (y) surface, polished into target surface f gri60 (y) and polished into standard profile surface f T60 Compared with (y), the difference in the area of ​​rail cross-section material removal ΔS(y) is the smallest:

[0056]

[0057] Where: ΔS gri60 (y) and ΔS T60 (y) are the target profiles of the worn rails. gri60 (y) The area of ​​rail cross-section material removed after grinding to the standard profile.

Claims

1. A method for designing a grinding profile of a rail before a high-speed turnout, characterized in that: The specific steps are: Step 1: Measure and collect the rail profile before the high-speed turnout; Step 2: Measure and collect the rail defects before the high-speed turnout; Step 3: Divide the rail profile into six equal areas horizontally, determine the upper and lower limits of the wear of the profile curve in each area, perform spectrum analysis on the wear, and calculate the deviation of the profile curve in each area from the standard profile curve. Step 4: Discretize the rail profile, and divide the wear upper and lower limit intervals of the profile curve in each area into multiple intervals; use the arithmetic mean fitting method to calculate the coordinate averages of each point on the rail profile curve in each interval in turn, as the representative points in each interval; further, fit through multi-segment function curves to generate rail grinding design profiles in 6 areas respectively; Step 5: Use the interpolation fitting method to fit the rail grinding design profile in each area obtained in step S4 to obtain the overall rail grinding design profile. Step 6: Establish turnout models based on different designed rail grinding profiles, and construct a vehicle-turnout system coupling dynamics analysis model based on the turnout model to verify the safety of the rail grinding design profile obtained in step S4; Step 7: Compare the actual measured profile on site with the designed grinding profile, consider the defect situation, and select the appropriate rail grinding profile based on the principle of minimum grinding amount.

2. A method for designing a grinding profile of a high-speed turnout rail according to claim 1, characterized in that: In step S1, the profile positions collected are the left and right rail profiles of the 1st to 4th sleepers in front of the turnout point rail tip that need to be polished, and the left and right rail profiles of the 5th, 10th, and 20th sleepers in front of the turnout.

3. A method for designing a grinding profile of a high-speed turnout rail according to claim 1, characterized in that: In step S2, collecting diseases includes recording whether there are scale injuries, fish pieces falling off and other diseases, and recording the depth of scale injuries and fish pieces falling off respectively.

4. A method for designing a grinding profile of a high-speed turnout rail as claimed in claim 1, characterized in that: In step S6, the verification method is based on the standard of GBT 5599-2019 "Specifications for Evaluation and Test of Locomotive and Rolling Stock Dynamics Performance", and the vehicle running stability, vehicle vibration acceleration, etc. are evaluated through simulation; if the rail design profile does not meet the verification, it is discarded, and after modifying the wear parameters in step S3, step S4 is performed again to generate a new design profile.

5. A method for designing a grinding profile of a high-speed turnout rail as claimed in claim 1, characterized in that: In step S7, the minimum grinding amount principle is: the worn rail f of a certain operating line worn60 (y) surface, polished into the target surface fgri 60 (y) and polished into standard profile surface f T60 Compared with (y), the difference in the area of ​​rail cross-section material removal ΔS(y) is the smallest: Where: ΔS gri60 (y) and ΔS T60 (y) are the target profiles of the worn rails. gri60 (y) The area of ​​rail cross-section material removed after grinding to the standard profile.

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