Reference test block for ultrasonic detection of waist hole of steel rail
By designing a comparative test block for ultrasonic testing of rail web holes, the problem of the inability to quickly distinguish the location of newly formed cracks in existing technologies has been solved, providing accurate test data and ensuring construction quality and safety.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-26
- Publication Date
- 2026-03-03
AI Technical Summary
Existing technology cannot quickly distinguish the location of newly formed cracks in the web holes of subway rails, and there is a lack of accurate and reliable detection data, which leads to safety hazards in bolted connections.
A comparative test block for ultrasonic testing of rail web holes is designed, which includes multiple rail web holes and cracks in different directions. The size is consistent with that of an actual rail, and a copper sleeve is installed to simulate different conditions and provide a testing reference.
It provides accurate and reliable testing data to help construction companies, testing service providers, and operators ensure construction quality, promote process improvement, and reduce safety risks.
Smart Images
Figure CN223966524U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the technical field of ultrasonic testing equipment for rail web holes, specifically relating to a comparative test block for ultrasonic testing of rail web holes. Background Technology
[0002] Subways are a type of urban rail transit system, referring to high-speed, high-capacity rail transit systems built in cities using electric traction. The traction power supply system, as the power source for subways, faces technological challenges. Currently, domestic power supply systems mainly use DC 750V and DC 1500V power supply systems, with overhead contact line suspension methods primarily including flexible suspension, rigid suspension, and contact rail power supply. For the traction power supply system, the traction network serves as the current source for the locomotive, and the rails serve as the return current source. The current ultimately flows back to the traction substation through cables connected to the rails. Because subways use DC power supply systems, the current is relatively large, requiring a large number of return cables. One method of connecting the return cables to the rails is bolted connection.
[0003] Bolted connections involve custom-made fishplates for rails, drilling holes in the rail web, and using bolts to connect the fishplate to the rail, achieving uniform flow and backflow. Bolted connections carry the following risks: 1) Drilling holes in the rail can damage the rail itself; 2) Poor contact and poor backflow can lead to high rail potential, resulting in rail-to-ground discharge and high-temperature melting at the rail-fishplate contact surface; 3) The bolt bushings are fixed to the inner wall of the bolt hole through expansion, creating residual stress. Therefore, ultrasonic testing of the bolt holes is necessary before construction and acceptance to ensure safety.
[0004] Because new cracks sometimes appear around the bolt holes during their formation, and these cracks are located in various positions, current ultrasonic testing methods for subway rail web holes cannot quickly distinguish the location of these new cracks, thus failing to provide accurate and reliable testing data for construction companies, testing service providers, and operators. Therefore, there is currently a lack of a comparative test block for ultrasonic testing of rail web holes. Utility Model Content
[0005] The technical problem to be solved by this utility model is to provide a comparative test block for ultrasonic testing of rail web holes, addressing the shortcomings of the prior art.
[0006] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is: a comparative test block for ultrasonic testing of rail web holes, characterized in that: it includes a rail-shaped test block, the rail-shaped test block includes a rail base, a rail web and a rail head, the rail web is provided with a first rail web hole, a second rail web hole, a third rail web hole, a fourth rail web hole and a fifth rail web hole at equal intervals along the length direction, the first rail web hole and the fifth rail web hole are free of artificial defects, the second rail web hole has a horizontal crack on one side of the middle part, the third rail web hole has an upward oblique crack on the upper left part, the third rail web hole has a downward oblique crack on the lower right part, the central axis of the upward oblique crack and the central axis of the downward oblique crack coincide and both pass through the center of the third rail web hole, and the fourth rail web hole has a vertical crack on the top or bottom.
[0007] The aforementioned comparative test block for ultrasonic testing of rail web holes is characterized in that: the dimensions of the rail-shaped test block are consistent with the dimensions of the actual rail.
[0008] The aforementioned comparative test block for ultrasonic testing of rail web holes is characterized in that: the diameters of the first, second, third, fourth, and fifth rail web holes are 10mm to 31mm; the intervals between the first, second, third, fourth, and fifth rail web holes are 100mm to 200mm; and the distances of the first and fifth rail web holes from the rail end face are not less than 40mm.
[0009] The aforementioned comparative test block for ultrasonic testing of rail web holes is characterized in that: the width of the horizontal crack, the upward oblique crack, the downward oblique crack, and the vertical crack is no greater than 0.5 mm, and the depth of the horizontal crack, the upward oblique crack, the downward oblique crack, and the vertical crack is 1.5 mm to 5 mm.
[0010] The aforementioned comparative test block for ultrasonic testing of rail web holes is characterized in that the angle between the central axis of the upward and downward oblique cracks and the horizontal line is 15° to 53°.
[0011] The aforementioned comparative test block for ultrasonic testing of rail web holes is characterized in that: copper sleeves fixed by press riveting are installed in the first, second, third, and fourth rail web holes.
[0012] The beneficial effects of this utility model are that it has a novel and reasonable design. By opening five rail waist holes, the first and fifth rail waist holes are used to compare the test results when a copper sleeve is installed, and the second to fourth rail waist holes are used to compare the test results under different orientations of cracks. This comparative test block can provide a reference for whether there are cracks and the ultrasonic test results under different orientations of cracks, providing accurate and reliable test data for construction parties, testing service providers, and operators, ensuring the quality of construction for construction parties, promoting the improvement of construction processes, and facilitating its widespread use.
[0013] The technical solution of this utility model will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description
[0014] Figure 1 This is a schematic diagram of the structure of the comparative test block of this utility model.
[0015] Figure 2 for Figure 1 The left view.
[0016] Figure 3 for Figure 2 A schematic diagram of the structure after adding the copper sleeve.
[0017] Explanation of reference numerals in the attached figures:
[0018] 1—rail base; 2—rail web; 3—rail head;
[0019] 4—First rail waist hole; 5—Second rail waist hole; 6—Third rail waist hole;
[0020] 7—Fourth rail waist hole; 8—Fifth rail waist hole; 9—Horizontal crack;
[0021] 10—Upward-sloping crack; 11—Downward-sloping crack; 12—Vertical crack;
[0022] 13—Copper sleeve. Detailed Implementation
[0023] like Figures 1 to 3 As shown, this utility model includes a rail-shaped test block, which includes a rail base 1, a rail web 2, and a rail head 3. The rail web 2 has a first rail web hole 4, a second rail web hole 5, a third rail web hole 6, a fourth rail web hole 7, and a fifth rail web hole 8 at equal intervals along its length. The first rail web hole 4 and the fifth rail web hole 8 are free of artificial defects. A horizontal crack 9 is formed on one side of the middle of the second rail web hole 5. An upward-sloping crack 10 is formed on the upper left of the third rail web hole 6, and a downward-sloping crack 11 is formed on the lower right of the third rail web hole 6. The central axis of the upward-sloping crack 10 and the central axis of the downward-sloping crack 11 coincide and both pass through the center of the third rail web hole 6. A vertical crack 12 is formed on the top or bottom of the fourth rail web hole 7.
[0024] It should be noted that by opening five rail web holes, the first and fifth rail web holes are used to compare the test results with and without copper bushings, while the second to fourth rail web holes are used to compare the test results under different orientations of cracks. This comparative test block can provide a reference for the presence of cracks and the ultrasonic test results under different orientations of cracks, providing accurate and reliable test data for construction parties, testing service providers, and operators, ensuring the quality of construction for the construction party, and promoting the improvement of construction processes.
[0025] In this embodiment, the dimensions of the rail-shaped test block are consistent with the dimensions of the actual rail.
[0026] In actual production, the material and dimensions of the rail-shaped test block are consistent with those of the actual rail.
[0027] In this embodiment, the diameters of the first rail waist hole 4, the second rail waist hole 5, the third rail waist hole 6, the fourth rail waist hole 7, and the fifth rail waist hole 8 are 10mm to 31mm, the intervals between the first rail waist hole 4, the second rail waist hole 5, the third rail waist hole 6, the fourth rail waist hole 7, and the fifth rail waist hole 8 are 100mm to 200mm, and the distances between the first rail waist hole 4 and the fifth rail waist hole 8 and the end face of the rail are not less than 40mm.
[0028] In this embodiment, the width of the horizontal crack 9, the upward oblique crack 10, the downward oblique crack 11, and the vertical crack 12 is no greater than 0.5 mm, and the depth of the horizontal crack 9, the upward oblique crack 10, the downward oblique crack 11, and the vertical crack 12 is 1.5 mm to 5 mm.
[0029] In this embodiment, the angle between the central axis of the upward oblique crack 10 and the downward oblique crack 11 and the horizontal line is 15° to 53°.
[0030] In this embodiment, copper sleeves 13, which are fixed by press riveting, are installed in the first rail waist hole 4, the second rail waist hole 5, the third rail waist hole 6 and the fourth rail waist hole 7.
[0031] In actual use, the material, geometric dimensions, and installation method of the copper sleeve 13 are consistent with those of the actual test track rail web hole.
[0032] In use, this invention defines the name of the crack based on the angle between the rail web hole crack and the longitudinal horizontal direction of the rail. A crack with an angle of 0° is called a horizontal crack, a crack with an angle of 90° is called a vertical crack, a crack with an angle above the longitudinal center of the rail is called an upper crack, and a crack with an angle below the longitudinal center of the rail is called a lower crack, such as an upper 15° crack, a lower 45° crack, etc. If a crack appears in the rail web hole, the screen will display two reflected waves (double waves): a rail web hole reflected wave and a crack reflected wave. The crack reflected wave follows the rail web hole reflected wave. During the actual testing process, some rail web holes were equipped with copper sleeves while others were not. First, ultrasonic testing was performed on the five rail web holes without copper sleeves to obtain the corresponding reflected wave waveforms for each rail web hole. Then, copper sleeves were installed on the first to fourth rail web holes, and ultrasonic testing was performed to obtain the reflected wave waveforms for the four rail web holes with copper sleeves. This comparative test block can provide a reference for the presence of cracks and the ultrasonic testing results under different orientations of cracks, providing accurate and reliable testing data for construction parties, testing service providers, and operators, thus ensuring construction quality and promoting process improvements.
[0033] The above description is merely a preferred embodiment of the present utility model and does not constitute any limitation on the present utility model. Any simple modifications, alterations, or equivalent structural changes made to the above embodiments based on the technical essence of the present utility model shall still fall within the protection scope of the present utility model.
Claims
1. A comparative test block for ultrasonic testing of rail web holes, characterized in that: The test block includes a rail base (1), a rail web (2), and a rail head (3). The rail web (2) is provided with a first rail web hole (4), a second rail web hole (5), a third rail web hole (6), a fourth rail web hole (7), and a fifth rail web hole (8) at equal intervals along its length. The first rail web hole (4) and the fifth rail web hole (8) are free of artificial defects. A horizontal crack (9) is provided on one side of the middle of the second rail web hole (5). An upward-sloping crack (10) is provided on the upper left of the third rail web hole (6). An downward-sloping crack (11) is provided on the lower right of the third rail web hole (6). The central axis of the upward-sloping crack (10) and the central axis of the downward-sloping crack (11) coincide and both pass through the center of the third rail web hole (6). A vertical crack (12) is provided at the top or bottom of the fourth rail web hole (7).
2. A comparative test block for ultrasonic testing of rail web holes according to claim 1, characterized in that: The dimensions of the rail-shaped test block are consistent with the dimensions of the actual rail.
3. A comparative test block for ultrasonic testing of rail web holes according to claim 1, characterized in that: The diameters of the first rail waist hole (4), the second rail waist hole (5), the third rail waist hole (6), the fourth rail waist hole (7), and the fifth rail waist hole (8) are 10mm to 31mm. The intervals between the first rail waist hole (4), the second rail waist hole (5), the third rail waist hole (6), the fourth rail waist hole (7), and the fifth rail waist hole (8) are 100mm to 200mm. The distance between the first rail waist hole (4) and the fifth rail waist hole (8) and the end face of the rail is not less than 40mm.
4. A comparative test block for ultrasonic testing of rail web holes according to claim 3, characterized in that: The width of the horizontal crack (9), the upward oblique crack (10), the downward oblique crack (11), and the vertical crack (12) is no greater than 0.5 mm, and the depth of the horizontal crack (9), the upward oblique crack (10), the downward oblique crack (11), and the vertical crack (12) is 1.5 mm to 5 mm.
5. A comparative test block for ultrasonic testing of rail web holes according to claim 4, characterized in that: The angle between the central axis of the upward-sloping crack (10) and the downward-sloping crack (11) and the horizontal line is 15° to 53°.
6. A comparative test block for ultrasonic testing of rail web holes according to claim 1, characterized in that: The first rail waist hole (4), the second rail waist hole (5), the third rail waist hole (6) and the fourth rail waist hole (7) are all fitted with copper sleeves (13) that are fixed by press riveting.