A new type of dynamic and static calibration test block for a double-track rail flaw detection vehicle

Abstract

The utility model relates to rail flaw detection technical field, and disclose a new type railway double rail flaw detection car flaw dynamic and static calibration test block. The new type railway double rail flaw detection car flaw dynamic and static calibration test block, including base plate and rail, the rail includes rail head, rail waist and rail bottom, the top fixedly connected with the rail of base plate is before and after symmetry distribution, the surface of rail head all is inlayed and set with wear -resisting alloy layer, the surface of rail head all is equipped with transverse slot type defect, this device has the advantages such as simplifying calibration procedure, improving calibration stability, reducing economy and site restriction, perfecting detection function, reducing comprehensive cost and improving centring accuracy, guaranteeing the accuracy and efficiency of flaw detection car detection, adapting to the development demand of railway flaw detection technology, solve the calibration operation of the existing railway double rail flaw detection car flaw dynamic and static calibration technology complicated, poor stability, is restricted by economy and site, test block function is insufficient, detects the cost is high and the problem of low centring calibration accuracy.

Description

Technical Field

[0001] This utility model relates to the field of rail flaw detection technology, specifically a novel dynamic and static calibration test block for a railway dual-rail flaw detection vehicle. Background Technology

[0002] In the railway transportation safety assurance system, rail flaw detection technology is a crucial link. With the development of railways towards high speed and heavy load, the requirements for the accuracy, efficiency, and coverage of rail flaw detection are increasing. Early railway flaw detection relied mainly on manual labor, with personnel using experience and simple tools, resulting in low efficiency, high susceptibility to human factors, and a high rate of missed detections. Later, analog flaw detection technology emerged. Analog flaw detectors, through the coordinated operation of multiple circuit components, convert ultrasonic signals into image information. They are simple in structure, easy to operate, and low in cost, but they cannot process and record signals, requiring manual recording of echoes, making it difficult to guarantee the accuracy of the detection results, leading to frequent missed and false detections. To improve this situation, digital technology was introduced into analog flaw detectors, enabling them to acquire, store, and process data, as well as self-diagnose and automatic speed control, reducing human interference. However, due to the limitations of microprocessor chips at the time, their functions were relatively simple. In the late 1980s, my country's general-purpose digital flaw detection technology began to take off. In 1989, Wuhan Zhongke Innovation Technology Co., Ltd. successfully developed a digital ultrasonic flaw detector, breaking the market monopoly and propelling ultrasonic flaw detection technology towards digitalization. Fully digital rail flaw detection technology, with digital signal processing and microprocessing as its core, can collect, process, and store data, and automatically determine defects. However, it suffers from high costs, instability in harsh environments, and room for improvement in operability. Regarding sensor technology, slipper-type sensors have high requirements for rail head shape and are easily affected by rail gaps and side wear, disrupting the coupling effect. Wheel-type sensors have better adaptability to the track and have been widely used in my country's railway flaw detection vehicles for many years; they will remain the primary type in the future, with slipper-type sensors as a supplement. The detection speed positioning of rail flaw detection vehicles has been continuously optimized. Considering various factors, the ideal detection speed for high-speed railways and passenger / freight mixed-use railways is set at 80-100 km / h, and my country has ultimately determined this range as the target speed value. In terms of flaw detection equipment calibration, the early system was imperfect, resulting in low detection accuracy. Currently, based on relevant technical conditions and project requirements, dual-track flaw detection for rail transit adopts a dynamic calibration method, laying low-speed and high-speed test lines to construct a complete calibration system, ensuring the accuracy of test data. For example, the Shuohuang Railway Company has established a calibration system covering the ultrasonic testing system from the probe wheel to the entire system, from static to dynamic calibration. The dual-track flaw detection area in the rail flaw detection workshop uses a combination of static and dynamic calibration methods for quarterly calibration. In the future, railway dual-track flaw detection technology is expected to develop towards higher precision, efficiency, and intelligence, and the dynamic and static calibration test blocks will be continuously optimized to meet the demands.

[0003] In existing technologies for railway rail flaw detection, the accuracy of dual-rail flaw detection vehicles relies on the precise calibration of the flaw detection system using dynamic and static calibration blocks. However, existing technologies have shortcomings. Currently, railway departments commonly use rail flaw detection vehicles for periodic ultrasonic flaw detection. The flaw detection vehicle introduced by Shuohuang Railway Company in 2013 has a maximum detection speed of 80 km / h, which is a significant advantage. However, the flaw detection standard uses artificial damage calibration lines, and each railway bureau has its own calibration lines. Sensitivity needs to be adjusted on these lines before each trip, requiring an artificial damage detection rate of ≥80% and a false alarm rate of ≤20%. While this method can reflect the on-site sensitivity adjustment, it has obvious drawbacks. Existing ultrasonic calibration blocks must meet the relevant requirements in TJGW157-2017 "Provisional Technical Conditions for Dual-Rail Ultrasonic Flaw Detectors," which limits their practical application. For example, in the quantitative analysis of specific defects during rail weld flaw detection, there is a lack of transverse beam width test blocks, and the longitudinal beam width test blocks have large depth increments, which is not conducive to accurate detection. Furthermore, wheeled ultrasonic probe equipment lacks specific test blocks during factory and acceptance testing, resulting in the inability to effectively detect some performance indicators. Existing test blocks used for wheeled ultrasonic rail flaw detection equipment, such as a comprehensive ultrasonic test block for rail flaw detection, can detect some performance indicators, but they are large in size and require specialized equipment during testing, increasing cost and operational complexity. In addition, the alignment and calibration of the flaw detection vehicle's probe wheels mostly rely on manual adjustment, which is prone to errors, affecting detection accuracy and reducing work efficiency.

[0004] The disadvantages of existing technologies are as follows: 1. Complex calibration operation: Using the manual damage calibration line as the standard, the sensitivity of each probe wheel needs to be dynamically adjusted before the vehicle is deployed. The process is complex, time-consuming, and labor-intensive, increasing preparation workload and manpower costs. 2. Poor calibration stability: After the probe wheel is repaired on-site, the original calibration value becomes invalid, requiring comprehensive recalibration. This seriously affects the continuity and timeliness of flaw detection work. In complex line environments, the probe wheel is easily damaged and repaired, and frequent calibration further reduces efficiency. 3. Constrained by economic and site conditions: Laying the manual damage calibration line requires high investment and is limited by terrain and space. Some lines (such as remote areas) are difficult to lay, resulting in the flaw detection vehicle being unable to be calibrated in a timely and effective manner. Moreover, the calibration cycle is long and cannot reflect the equipment status in real time. 4. Insufficient test block functions: Existing test blocks lack a transverse beamwidth detection structure, and the depth increment value of the longitudinal beamwidth detection test block is large, which is not conducive to accurate detection. There is a lack of dedicated test blocks for wheeled ultrasonic probe equipment, resulting in some performance indicators being unable to be effectively verified. 5. High testing costs: Existing wheel-type flaw detectors require large test blocks and specialized testing devices, increasing equipment procurement and maintenance costs, complicating operation, and raising the application threshold. 6. Low centering and calibration accuracy: Wheel centering relies on manual adjustment, which is prone to errors due to differences in operator experience, affecting the accuracy of flaw detection results. Furthermore, the adjustment is time-consuming, reducing overall work efficiency.

[0005] In summary, a novel dynamic and static calibration test block for railway dual-rail flaw detection vehicle is proposed to solve the above problems. Utility Model Content

[0006] Technical problems to be solved To address the shortcomings of existing technologies, this utility model provides a novel dynamic and static calibration test block for railway dual-rail flaw detection vehicles. This block simplifies the calibration process, improves calibration stability, reduces economic and site limitations, enhances testing functions, lowers overall costs, and improves alignment accuracy. It ensures the accuracy and efficiency of flaw detection vehicle testing and meets the development needs of railway flaw detection technology. This invention solves the problems of complex calibration operations, poor stability, economic and site constraints, insufficient test block functionality, high testing costs, and low alignment accuracy in existing dynamic and static calibration technologies for railway dual-rail flaw detection vehicles.

[0007] (II) Technical Solution The technical solution of this utility model to solve the above-mentioned technical problems is as follows: A novel dynamic and static calibration test block for railway dual-rail flaw detection vehicle, comprising a base plate and a rail, wherein the rail comprises a rail head, a rail web and a rail bottom, the top of the base plate is fixedly connected with rails symmetrically distributed front and back, the surface of the rail head is embedded with a wear-resistant alloy layer, the surface of the rail head is provided with transverse groove defects, the interior of the rail head is provided with longitudinal groove defects, the surface of the rail web is provided with oblique defect groups, and the rail bottom is provided with flat-bottomed defect holes and longitudinal cracks.

[0008] The longitudinal length of each rail is 6000-8000 mm, and the rail spacing is 1435 mm.

[0009] The transverse groove defect consists of transverse grooves that are evenly distributed laterally. The depths of the transverse grooves are 0.5mm, 1mm, 2mm, 3mm and 5mm, respectively, and the spacing between adjacent transverse grooves is 10mm.

[0010] The longitudinal groove defect adopts a stepped longitudinal groove defect with a depth increment of 0.2 mm, and the depth range of the longitudinal groove defect is 1-5 mm.

[0011] The oblique defect group includes simulated cracks with three inclination angles of 30°, 45° and 60°. The length of the simulated cracks is 5-20 mm and the width is 0.1-0.3 mm.

[0012] The flat-bottom defect hole is perpendicular to the rail bottom surface, and the hole diameters of the flat-bottom defect hole are 1mm, 3mm and 5mm respectively. The longitudinal crack is parallel to the longitudinal axis of the rail, and the length of the longitudinal crack is 10-30mm.

[0013] The front and rear sides of the rail head are affixed with reflective marks that are distributed horizontally at equal intervals, with a spacing of 100 mm between adjacent reflective marks.

[0014] Laser alignment reference lines are engraved on both the front and rear sides of the rail head.

[0015] The beneficial effects of this utility model are: 1) The new type of railway dual-rail flaw detection vehicle integrates a dual-rail structure and multiple types of defects into one test block. It does not rely on manual damage calibration lines. Static and dynamic calibration can be completed on the same test block, reducing the step of calibrating each probe wheel individually, reducing labor costs and preparation time, improving calibration efficiency, and has the advantage of simplifying the calibration process.

[0016] 2) The new type of railway dual-rail flaw detection vehicle uses dynamic and static calibration test blocks. The defect size of the rail test blocks is stable. After the test wheel is repaired, it can be directly recalibrated on the test blocks without the need to re-lay calibration lines. This ensures the traceability and continuity of calibration values, reduces the impact on the progress of flaw detection work, and has the advantage of improving calibration stability.

[0017] 3) The new type of railway dual-rail flaw detection vehicle's dynamic and static calibration test block, the integral rail test block can be fixedly installed in the laboratory or maintenance base, without the need for large-scale laying of on-site calibration lines, reducing dependence on line conditions and economic investment, and is especially suitable for the calibration needs of railway flaw detection vehicles in remote areas, with the advantages of reducing economic and site restrictions.

[0018] 4) The new type of railway dual-rail flaw detection vehicle has dynamic and static calibration test blocks to supplement the detection of transverse sound beam width defects and high-precision longitudinal step defects, realizing the full performance index verification of wheel probe equipment; the oblique defect group and rail bottom defects cover common damage types, improving the comprehensiveness of calibration and possessing the advantage of perfect detection function.

[0019] 5) The dynamic and static calibration test blocks of this new type of railway dual-rail flaw detection vehicle do not require special testing equipment. The test blocks come with a wear-resistant layer and a baseline, reducing the frequency of equipment maintenance and replacement. The long-term use cost is lower than the traditional combination of calibration lines and dispersed test blocks, thus having the advantage of reducing overall costs.

[0020] 6) The new type of railway dual-rail flaw detection vehicle uses dynamic and static calibration test blocks for flaw detection. The laser alignment reference line, combined with the automatic alignment device, controls the alignment error within ±0.5mm, reduces manual operation error, and improves the accuracy and consistency of flaw detection results, thus having the advantage of improving alignment accuracy. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of this utility model; Figure 2 This is an enlarged schematic diagram of the structure at point a of this utility model; Figure 3 This is a cross-sectional view of the rail structure of this utility model; Figure 4 This is a schematic diagram of a partial structure of the rail web of this utility model; Figure 5 This is a schematic diagram of a partial structure of the rail base of this utility model.

[0022] In the figure: 1. Base plate; 2. Rail; 2a. Rail head; 2b. Rail web; 2c. Rail bottom; 3. Wear-resistant alloy layer; 4. Transverse groove defect; 5. Longitudinal groove defect; 6. Oblique defect group; 7. Flat bottom defect hole; 8. Longitudinal crack; 9. Reflective mark; 10. Laser alignment reference line. Detailed Implementation

[0023] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0024] In the embodiments, by Figure 1-5 This invention discloses a novel dynamic and static calibration test block for a railway dual-rail flaw detection vehicle. The invention includes a base plate 1 and a rail 2. The rail 2 includes a rail head 2a, a rail web 2b, and a rail base 2c. The top of the base plate 1 is fixedly connected to the rails 2, which are symmetrically distributed front and back. The surface of the rail head 2a is embedded with a wear-resistant alloy layer 3. The surface of the rail head 2a is provided with transverse groove defects 4. The interior of the rail head 2a is provided with longitudinal groove defects 5. The surface of the rail web 2b is provided with oblique defect groups 6. The rail base 2c is provided with flat-bottomed defect holes 7 and longitudinal cracks 8. The longitudinal length of each rail 2 is 6000-8000 mm, and the spacing between the rails 2 is 1435 mm. The transverse groove defect 4 consists of transverse grooves that are evenly distributed in the transverse direction. The depths of the transverse grooves are 0.5mm, 1mm, 2mm, 3mm and 5mm, respectively, and the spacing between adjacent transverse grooves is 10mm. The longitudinal groove defect 5 adopts a stepped longitudinal groove defect with a depth increment of 0.2 mm, and the depth range of the longitudinal groove defect 5 is 1-5 mm; The oblique defect group 6 includes simulated cracks with three inclination angles of 30°, 45° and 60°. The length of the simulated cracks is 5-20 mm and the width is 0.1-0.3 mm. The flat-bottom defect hole 7 is perpendicular to the rail bottom surface, and the diameters of the flat-bottom defect hole 7 are 1mm, 3mm and 5mm respectively. The longitudinal crack 8 is parallel to the longitudinal axis of the rail 2, and the length of the longitudinal crack 8 is 10-30mm. Reflective marks 9 are affixed to both the front and rear sides of the rail head 2a in a horizontally equidistant manner, with a spacing of 100 mm between adjacent reflective marks 9; Laser alignment reference lines 10 are engraved on both the front and rear sides of the rail head 2a.

[0025] Working principle: Park the flaw detection vehicle at the starting end of rail 2 test block, turn on the laser alignment device, align the probe wheel with the laser alignment reference line 10, record the initial alignment parameters, control the flaw detection vehicle to travel along rail 2 test block at a speed of 2km / h, and sequentially detect transverse groove-shaped defects in area 4, record the echo height of defects at different depths, adjust the flaw detector gain to the standard echo amplitude (80% full screen), complete the sensitivity calibration, detect longitudinal groove-shaped defects in area 5, record the echo width corresponding to each step depth, verify the longitudinal resolution of the sound beam, and ensure that a depth difference of 0.2mm can be effectively detected.

[0026] Test block preparation process: Raw material selection: Low-carbon alloy steel billets (chemical composition: C 0.65-0.75%, Si 0.15-0.35%, Mn 1.10-1.40%, P≤0.030%, S≤0.030%) with the same material as U71Mn steel rails are used to ensure that the acoustic performance is consistent with the actual steel rail 2.

[0027] Forging and Machining: After forging at 1200℃, the steel billet is rolled into a 6-meter-long double rail blank, with the gauge controlled at 1435±0.5mm. The rail head 2a transverse groove defect 4 is machined using a CNC milling machine: depth 0.5mm, 1mm, 2mm, 3mm, 5mm, width 0.2mm, length 50mm, adjacent defect spacing 10mm, machining accuracy ±0.05mm; the longitudinal groove defect 5 is machined using electrical discharge machining: depth starts from 1mm, increasing in increments of 0.2mm to 5mm, step width 20mm, sidewall verticality ≤0.01mm; the rail web 2b oblique defect group 6 is machined using wire cutting: 30°, 45°, 60°... The inclination angles are 5mm, 10mm, 15mm, and 20mm respectively, the width is 0.1mm, and the radius of the crack tip is ≤0.05mm; the flat bottom defect hole 7 of the rail bottom 2c is drilled and then ground: the diameter is 1mm, 2mm, and 3mm, the hole depth is 10mm, and the surface roughness of the hole bottom surface Ra≤0.8μm. The longitudinal crack 8 is processed by an ultraviolet laser engraving machine.

[0028] Surface treatment: The surface of rail head 2a is overlaid with wear-resistant alloy (composition: Cr 15-18%, Ni 3-5%, Mo 2-3%), with a thickness of 2mm. After welding, it is tempered at 500℃ to eliminate stress. The speed calibration sections at both ends of rail head 2a are laser-engraved with reflective marks 9 at 100mm intervals, with a mark line width of 0.5mm and a contrast of ≥90%. The two sides of the rail head are laser-engraved with 0.1mm wide laser alignment reference lines 10, with a straightness of ≤0.1mm / m.

[0029] Accuracy inspection: A coordinate measuring machine (accuracy ±0.001mm) is used to inspect all defect dimensions, track gauge, and baseline position to ensure compliance with design requirements.

[0030] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0031] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A new type of dynamic and static calibration test block for a new railway double-track flaw detection vehicle, comprising a base plate (1) and a steel rail (2), wherein the steel rail (2) comprises a rail head (2a), a rail waist (2b) and a rail bottom (2c), characterized in that: The top of the base plate (1) is fixedly connected with steel rails (2) that are symmetrically distributed front and back. The surface of the rail head (2a) is embedded with a wear-resistant alloy layer (3). The surface of the rail head (2a) is provided with transverse groove defects (4). The interior of the rail head (2a) is provided with longitudinal groove defects (5). The surface of the rail web (2b) is provided with oblique defect groups (6). The bottom of the rail (2c) is provided with flat-bottom defect holes (7) and longitudinal cracks (8).

2. The novel dynamic and static calibration block for a double-track rail flaw detection vehicle according to claim 1, characterized in that: The longitudinal length of each rail (2) is 6000-8000 mm, and the spacing between the rails (2) is 1435 mm.

3. The novel dynamic and static calibration block for a double-track rail flaw detection vehicle according to claim 2, characterized in that: The transverse groove defect (4) is a transverse groove that is distributed at equal intervals in the transverse direction. The depths of the transverse grooves are 0.5mm, 1mm, 2mm, 3mm and 5mm respectively, and the distance between adjacent transverse grooves is 10mm.

4. The novel dynamic and static calibration block for a double-track rail flaw detection vehicle according to claim 3, characterized in that: The longitudinal groove defect (5) adopts a stepped longitudinal groove defect with a depth increment of 0.2 mm, and the depth range of the longitudinal groove defect (5) is 1-5 mm.

5. The novel dynamic and static calibration block for a double-track rail flaw detection vehicle according to claim 4, characterized in that: The oblique defect group (6) includes simulated cracks with three inclination angles of 30°, 45° and 60°. The length of the simulated crack is 5-20 mm and the width is 0.1-0.3 mm.

6. The novel dynamic and static calibration block for a double-track rail flaw detection vehicle according to claim 5, characterized in that: The flat-bottom defect hole (7) is perpendicular to the rail bottom surface. The diameters of the flat-bottom defect hole (7) are 1mm, 3mm and 5mm respectively. The longitudinal crack (8) is parallel to the longitudinal axis of the rail (2). The length of the longitudinal crack (8) is 10-30mm.

7. The novel dynamic and static calibration block for a double-track rail flaw detection vehicle according to claim 6, characterized in that: The front and rear sides of the rail head (2a) are covered with reflective marks (9) that are distributed horizontally at equal intervals, and the spacing between adjacent reflective marks (9) is 100 mm.

8. The novel dynamic and static calibration block for a double-track rail flaw detection vehicle according to claim 7, characterized in that: Laser alignment reference lines (10) are engraved on both the front and rear sides of the rail head (2a).

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