A method for correcting the symmetry imbalance of a rail end that is twisted beyond the standard

Abstract

The application discloses a symmetrical imbalance compensation and correction method for excessive rail end torsion, which comprises the following steps: selecting a rail, wherein the rail comprises a rail head, a rail waist and a rail bottom; measuring the rail bottom end torsion value; selecting the rail with excessive rail bottom end torsion value; placing the pad according to the direction of the rail bottom end torsion on different parts of the rail bottom, and placing the pressing block in the middle of the rail head to correct the rail bottom end torsion value to be qualified; correcting the rail with qualified rail bottom end torsion value to be flatness qualified, and completing the symmetrical imbalance compensation and correction of the rail end torsion. The application sets two pads in the diagonal direction of the rail bottom of the rail with excessive end torsion, forms an inclined surface with an angle of 1-5 degrees between the contact position of the pad and the rail bottom, and sets a pressing block in the middle of the rail head of the rail with excessive end torsion. The method is simple and effective, can correct the end torsion of rails of various types and sizes, and has strong popularization and applicability.

Description

Technical Field

[0001] This invention relates to the technical field of rail end torsion correction methods, and in particular to a symmetrical imbalance correction method for excessive rail end torsion. Background Technology

[0002] Excessive end torsion of rails not only affects the straightness of the finished rails but also the welding process at the rail welding plant after they leave the factory. Furthermore, track torsion after entering the line not only causes track irregularities but also significantly worsens wheel-rail dynamic interaction, with maximum lateral and vertical forces exceeding 15.2 kN and 131.8 kN respectively, seriously impacting operational safety. Therefore, it is essential to control the end torsion of rails within the standard allowable range before they leave the factory.

[0003] Therefore, it is of great significance to develop a method for effectively correcting the end torsion of rails. Summary of the Invention

[0004] This invention provides a method for correcting symmetrical imbalances caused by excessive torsion at the ends of rails, including...

[0005] Select a rail, which includes a rail head, rail web and rail base; measure the torsion value at the rail base end; and select rails whose torsion value at the rail base end exceeds the standard.

[0006] Place pads at different parts of the rail base according to the direction of the rail base twist, and place a pressure block in the middle of the rail head to correct the rail base twist value to the qualified level;

[0007] The rails whose torsion values ​​at the bottom end have been corrected to be within acceptable limits are then straightened to be within acceptable limits, thus completing the symmetrical imbalance correction of the torsion at the rail ends.

[0008] Furthermore, the step of placing the pad at different locations on the rail bottom according to the direction of the rail bottom end's twist includes,

[0009] When the positive end torsion value of the rail base exceeds the standard, place the first pad on the other side of the position of the measuring contact point for measuring the torsion of the rail base end, and place the second pad diagonally opposite to the first pad at the other end of the rail base.

[0010] When the negative direction end torsion value of the rail base exceeds the standard, the first pad is placed at the position of the measuring contact point for measuring the torsion at the end of the rail base, and the second pad is placed diagonally opposite to the first pad at the other end of the rail base.

[0011] Furthermore, the pad is rectangular in shape;

[0012] The contact position between the pad and the rail base has an inclination angle of 1-5° with respect to the rail base, and the direction of the inclination angle is biased towards the inside of the rail base.

[0013] Furthermore, the parameters of the pad are as follows:

[0014] Dimensions: Length 100-200mm, Width 20-50mm, Height 20-30mm;

[0015] Tensile strength, not greater than 600 MPa.

[0016] Furthermore, all edges of the pad are chamfered.

[0017] Furthermore, the pressing block is rectangular in shape.

[0018] Furthermore, all the edges of the pressing block are chamfered.

[0019] Furthermore, the parameters of the pressing block are as follows:

[0020] Dimensions: Length 120-300mm, width 1.1-1.5 times the width of the rail head, height 100-300mm;

[0021] Tensile strength, not greater than 600 MPa.

[0022] Furthermore, the torsion value at the bottom end of the measuring rail includes,

[0023] The rail end section is used as the measurement reference, and a torsion ruler is used to measure the measurement contact point at the bottom of the rail.

[0024] The distance between the center of the measuring contact and the edge of the rail bottom is 10mm.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] This invention involves placing two pads diagonally along the base of a rail with excessive end torsion. The contact points between the pads and the rail base form a 1-5° incline with the rail base. A pressure block is also placed in the middle of the rail head of the rail with excessive end torsion. This symmetrical, unbalanced padding design decomposes the vertical force on the rail with excessive end torsion into two parts: vertical force and lateral force. Combined with the pads, this lateral force causes a slight torsional deformation in the end rail, with the pressure contact point as the fixed end, thus correcting the torsion value. This method is simple and effective, capable of correcting end torsion in various types of standard-length rails, improving economic efficiency, and possessing strong applicability and scalability.

[0027] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the steps indicated in the description and the drawings. Attached Figure Description

[0028] 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 some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 A flowchart of a symmetrical imbalance correction method for excessive torsion at the end of a rail, according to an embodiment of the present invention, is shown.

[0030] Figure 2 This illustrates the arrangement of the pads under the rail in an embodiment of the present invention;

[0031] Figure 3 A schematic diagram of a pad block placed at the bottom of the rail and a pressure block placed in the middle of the rail head is shown in an embodiment of the present invention;

[0032] Figure 4 A schematic diagram showing the direction of the force in the symmetrical unbalanced padding configuration of an embodiment of the present invention is shown. Detailed Implementation

[0033] The endpoints and any values ​​of the ranges disclosed in this invention are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this invention.

[0034] To address the problem of excessive torsion at the rail ends, this invention involves placing two pads diagonally along the bottom of the rail where the torsion exceeds the limit. The contact points between the pads and the rail bottom form an inclined surface with the rail bottom. A pressure block is also placed in the middle of the rail head of the rail where the torsion exceeds the limit. This symmetrical and unbalanced padding design decomposes the vertical force on the rail with excessive torsion into two parts: vertical force and lateral force. Combined with the effect of the pads, this lateral force causes a slight torsional deformation in the rail end, with the pressure contact point as the fixed end, thereby correcting the torsion value.

[0035] The technical solutions of the present invention will be clearly and completely described below with reference to specific embodiments and 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.

[0036] Example

[0037] For a 60kg / m 100m high-speed rail, the end torsion measurement value is required to be ≤0.45mm / m. In the actual measurement process, there is a problem with the positive and negative directions of the measurement. Therefore, the end torsion measurement value should be within the range of -0.45mm / m to +0.45mm / m; a torsion value exceeding this range is considered to be out of standard.

[0038] like Figure 1 As shown, in one embodiment of the present invention, a method for correcting symmetrical imbalance caused by excessive torsion at the end of a rail is provided, comprising the following steps:

[0039] S101. Select a rail, which includes a rail head, rail web and rail base. Measure the torsion value at the rail base end and select rails whose torsion value at the rail base end exceeds the standard.

[0040] In step S101, the measurement of rail end torsion includes using the rail end cross-section as the measurement reference and measuring the measurement contact point at the bottom of the rail with a torsion ruler; the distance between the center of the measurement contact point and the edge of the bottom of the rail is 10mm.

[0041] S102. Place the pads at different parts of the rail base according to the direction of the rail base torsion, and place a pressure block in the middle of the rail head to correct the rail base torsion value to the qualified level.

[0042] like Figure 2 As shown on the left, in step S101, when the positive end torsion value of the rail base exceeds the standard, the first pad is placed on the other side of the position of the measuring contact point for measuring the end torsion of the rail base, and the second pad is arranged diagonally with the first pad at the other end of the rail base.

[0043] like Figure 2 As shown on the right, when the negative direction end torsion value of the rail base exceeds the standard, the first pad is placed at the position of the measuring contact point for measuring the end torsion of the rail base, and the second pad is arranged diagonally with the first pad at the other end of the rail base.

[0044] The pressure block is rectangular in shape. Its parameters are as follows: dimensions: length 120-300mm, width 1.1-1.5 times the rail head width, height 100-300mm; preferably, length 200mm, width 80mm, height 200mm. The tensile strength is generally selected as 1 / 3-1 / 2 of the rail's tensile strength, not exceeding 600MPa. The pressure block has a rectangular structure, and the surface of the block used to press against the curved tread of the rail head is planar. This ensures that during rail straightening, the downward pressure applied by the block to the curved tread of the rail head is always at the apex of the curved tread, effectively avoiding lateral forces on the rail and preventing lateral bending during straightening. All edges of the pressure block are chamfered to reduce the risk of the corresponding edges scratching the curved tread of the rail head during straightening.

[0045] In this embodiment, the first pad and the second pad are used only for distinguishing description; the first pad and the second pad are completely identical. The pad is rectangular in shape, with the following parameters: dimensions: length 100-200mm, width 20-50mm, height 20-30mm; preferably, the dimensions are 200mm long, 50mm wide, and 30mm high. The tensile strength is generally selected as 1 / 3-1 / 2 of the rail's tensile strength, not exceeding 600MPa. The contact position between the pad and the rail base has an angle of 1-5° with the rail base, the direction of which is biased towards the inner side of the rail base; preferably, the angle is 2°. All edges of the pad are chamfered to reduce the risk of the corresponding edges scratching the rail base during straightening.

[0046] like Figure 3 As shown, after the first and second pads are placed at the bottom of the rail, a pressure block is then placed in the middle of the rail head.

[0047] like Figure 4 As shown, this symmetrical unbalanced padding method decomposes the vertical force of the rail with excessive end torsion into a part of vertical force and another part of lateral force. With the help of the pads, the lateral force causes the end rail to undergo slight torsional deformation with the pressure contact position as the fixed end, thereby correcting the end torsion value of the rail.

[0048] Generally, the end torsion value of rails is not very large, and even if it exceeds the standard, the change in value does not need to be too large during the correction process. Therefore, large point straightening forces are not required during torsion correction operations. A slight deformation in the vertical direction of the rail, which is visible to the naked eye, is sufficient. Because the rail undergoes plastic deformation during the torsion correction process, the corrected torsion value will not revert or rebound.

[0049] In actual operation, the end of the rail with excessive end torsion is placed into the bidirectional hydraulic system, with one end positioned precisely at the lower anvil of the bidirectional hydraulic system. Following the shim block placement method in step S102, shims are placed on one side of each of the two lower anvils. Then, a pressure block is placed in the middle of the rail head of the rail with excessive end torsion for correction. After correction, the rail is removed from the bidirectional hydraulic system, and the end torsion is tested again. If the torsion value at the rail base is still excessive, correction is performed again according to step S102 until the torsion value at the rail base is corrected to a acceptable level.

[0050] S103. Correct the straightness of the rails whose torsion value at the bottom end has been corrected to meet the standard, and complete the symmetrical imbalance correction of the torsion at the rail end.

[0051] Rails that have passed end torsion correction must undergo straightness correction. After end torsion correction, no padding is placed under the rail; the rails that have passed end torsion correction are only subjected to vertical compression. During the end torsion correction process, after elastic-plastic deformation, straightness correction only improves the vertical curvature and does not affect the end torsion value. Therefore, the vertical and lateral curvatures of rails that have passed end torsion correction are corrected until straightness is satisfactory, at which point they can be released for storage.

[0052] Application Examples

[0053] The symmetrical imbalance correction method for excessive end torsion of rails in the embodiments of the present invention is applied to the Panzhihua Iron and Steel Group rail beam finishing line to correct rails whose end torsion does not meet the standard.

[0054] Currently, the annual output of 100m standard-length rails is about 800,000 tons. Assuming a 1% failure rate due to excessive torsion, the price difference between 100m and 25m standard-length rails is 500 yuan / ton. The annual output of 25m rails is about 600,000 tons, with a scrap rate of about 0.5% due to excessive torsion. The price difference between standard and scrap products is about 2,000 yuan / ton.

[0055] The results show that, using the method of this invention, 100m standard-length rails with excessive torsion can be salvaged during production. This avoids the situation where rails can only be cut to 25m lengths for delivery due to incorrect torsion values. Furthermore, 25m standard-length rails with excessive torsion at the ends can also be salvaged and delivered as good products, avoiding direct scrapping. This solves the long-standing technical problem of torsion at the ends of long-length rails that has plagued enterprises, generating approximately 10 million yuan in annual profits and creating considerable economic benefits for the company.

[0056] In summary, this invention involves placing two pads diagonally along the bottom of a rail with excessive end torsion. The contact points between the pads and the rail bottom form a 1-5° incline with the rail bottom. A pressure block is also placed in the middle of the rail head of the rail with excessive end torsion. This symmetrical and unbalanced padding design decomposes the vertical force of the rail with excessive end torsion into two parts: vertical force and lateral force. Combined with the effect of the pads, this lateral force causes a slight torsional deformation in the end rail, with the pressure contact point as the fixed end, thereby correcting the torsion value. This method is simple and effective, capable of correcting end torsion in various types of standard-length rails, improving economic efficiency, and possessing strong applicability and scalability.

[0057] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for correcting symmetrical imbalance caused by excessive torsion at the ends of rails, characterized in that, include, Select a rail, which includes a rail head, rail web and rail base; measure the torsion value at the rail base end; and select rails whose torsion value at the rail base end exceeds the standard. The first and second pads are placed at different parts of the rail bottom according to the direction of the rail bottom end torsion, and a pressure block is placed in the middle of the rail head to correct the torsion value of the rail bottom end to the qualified level; the pressure block is cuboid in shape, and all the edges of the pressure block are chamfered; the dimensions of the pressure block are 120-300mm in length, 1.1-1.5 times the width of the rail head, and 100-300mm in height. The rails with qualified torsion values ​​at the bottom end are straightened to qualified straightness, thus completing the symmetrical imbalance correction of the torsion at the rail end. The step of placing the first pad and the second pad at different locations on the rail bottom according to the direction of the twist at the rail bottom end includes... When the positive end torsion value of the rail base exceeds the standard, place the first pad on the other side of the position of the measuring contact point for measuring the torsion of the rail base end, and place the second pad diagonally opposite to the first pad at the other end of the rail base. When the negative direction end torsion value of the rail base exceeds the standard, the first pad is placed at the position of the measuring contact point for measuring the torsion at the end of the rail base, and the second pad is placed diagonally opposite to the first pad at the other end of the rail base. Both the first pad and the second pad are rectangular parallelepipeds with dimensions of 100-200mm in length, 20-50mm in width, and 20-30mm in height. The contact position between the first pad and the rail base has an angle of 1-5° with the rail base, the angle being biased towards the inside of the rail base. The contact position between the second pad and the rail base has an angle of 1-5° with the rail base, the angle being biased towards the inside of the rail base. Both the first pad and the second pad have chamfered edges.

2. The method of claim 1, wherein, The tensile strength of both the first and second pads is no greater than 600 MPa.

3. The method of claim 1, wherein, The tensile strength of the briquette is not greater than 600 MPa.

4. The method of claim 1, wherein, The measurement of the torsion value at the bottom of the rail includes measuring the rail bottom contact point with a torsion ruler, using the rail end section as the measurement reference; the distance between the center of the measurement contact point and the edge of the rail bottom is 10mm.

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