Thin seam stand column welding seam defect detection device
By designing pressure testing fixtures for the outer and middle cylinder welds on the hydraulic support columns of thin coal seams, efficient inspection of weld quality before assembly was achieved, solving the inspection problem in existing technologies and improving production efficiency and product quality.
Patent Information
- Application Number
- CN202422665633.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-01
- Publication Date
- 2025-11-04
- Estimated Expiration
- 2034-11-01
AI Technical Summary
Existing technologies make it difficult to perform effective non-destructive testing during the welding process of hydraulic support columns in thin coal seams. This results in the need for disassembly and repeated processing when problems are found after assembly, increasing losses and costs.
A defect detection device for weld seams of thin coal seam pillars is designed, including an outer cylinder and a middle cylinder weld seam pressure testing fixture. Seamless pipes and sealing structures are used to inspect the weld quality before assembly, ensuring that the pressure testing medium fully contacts the weld seam area and detects potential defects.
It improved the accuracy and reliability of weld inspection, reduced repeated disassembly and assembly losses, lowered production costs and time waste, and increased the pass rate of column assembly.
Smart Images
Figure CN223512859U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of weld inspection technology, specifically to a device for detecting weld defects in thin coal seam columns. Background Technology
[0002] Thin coal seams occupy an important position in my country's coal resources. They are abundant and widely distributed, but their mining is difficult and inefficient. As coal resources become increasingly depleted, the mining of thin coal seams is becoming more and more important.
[0003] Mining extremely thin coal seams is highly challenging, placing stringent requirements on mining equipment. Hydraulic supports, as a key component of the support system, directly impact the quality and safety of coal mine production. This is especially true for extremely thin coal seams, where the limited space makes traditional hydraulic supports ill-suited to the complex geological environment, necessitating higher design and application standards. In China, the primary type of hydraulic support for thin coal seams is the two-column shield type. Due to space constraints, the dimensions of the hydraulic supports must be as compatible as possible with the thickness of the mined thin coal seam. Consequently, the total stroke of the support columns is typically short.
[0004] Because thin coal seam supports are relatively low and have limited space, the columns cannot be designed using traditional structural forms. Therefore, a new type of hydraulic support column with perforated cylinder walls was designed and developed specifically for thin coal seam supports. This eliminates the need for welded joint seats, fluid pipes, and control valve seats on the outside of the cylinder of traditional hydraulic support columns, saving space and facilitating the overall structural design and layout of the hydraulic support. However, since thin coal seam hydraulic support columns are generally double telescopic columns with a cylinder diameter of Φ230~320 mm, the wall thickness of their outer and middle cylinders is generally 26~30 mm. mm, because the structure of the outer cylinder of the column is much more complex than that of ordinary brackets, the parts that need to be welded on the outer cylinder include the upper chamber return seat plate, the lower chamber inlet seat plate, the lug seat, the hydraulic control valve plate connector block, the small tube, the tube seat and the lifting ring, etc. There are also deep holes on the cylinder wall of the middle cylinder, which increases the difficulty of processing. During the welding process of the outer cylinder and the middle cylinder, it is difficult to check all the problems in the welds using existing non-destructive testing methods. It is only possible to see if there are any problems in the processed column after all the parts are processed and assembled and pressure tests are performed on the assembled column.
[0005] During actual pressure testing, it was found that the column could not maintain pressure, making it difficult to analyze whether the leak was in a part of the middle cylinder or the outer cylinder. The column with the problem during pressure testing needed to be disassembled for inspection, but reassembling and disassembling it could easily damage the seal and cause unnecessary losses. Therefore, if the quality problems of the outer cylinder and the middle cylinder itself can be checked before assembly and pressure testing, the work of repeatedly assembling and disassembling the column can be reduced, losses can be reduced, and work efficiency can be improved. Utility Model Content
[0006] The purpose of this invention is to provide a defect detection device for weld seams of thin coal seam pillars to overcome the problems existing in the prior art. This invention can independently check whether there are defects in the weld seams of the outer cylinder and the middle cylinder that affect the sealing of the pillar. By checking whether there are defects in the weld seams before assembly, it can avoid the difficulty in diagnosing the cause of internal leakage problems after assembly, improve the pass rate of the first assembly pressure test of the pillar, and thus reduce production costs. It also reduces the probability of damage to the seal due to repeated disassembly and assembly of the pillar caused by internal and external leakage, and reduces the wear and tear of the sealing components.
[0007] To achieve the above objectives, the technical solution adopted by this utility model is as follows:
[0008] A thin coal seam column weld defect detection device includes an outer cylinder weld pressure testing fixture installed at the outer cylinder port and a middle cylinder weld pressure testing fixture installed at the middle cylinder port.
[0009] The outer cylinder weld pressure test fixture includes an outer cylinder weld pressure test body. An outer cylinder detection baffle is fixed to the bottom inner wall and the top inner wall of the outer cylinder weld pressure test body. A first thread is provided on the top outer wall of the outer cylinder weld pressure test body. A first sealing groove is provided on the bottom outer wall of the outer cylinder weld pressure test body. A sealing ring is nested in the first sealing groove. A first lifting ring is fixed to the top of the outer cylinder weld pressure test body.
[0010] The pressure testing fixture for the middle cylinder weld seam includes a middle cylinder weld seam pressure testing body. The bottom inner wall and top inner wall of the middle cylinder weld seam pressure testing body are respectively fixed with a middle cylinder detection baffle. The top outer wall of the middle cylinder weld seam pressure testing body is provided with a second thread. The outer wall of the middle cylinder weld seam pressure testing body is provided with a second sealing groove and a third sealing groove. The second sealing groove and the third sealing groove are respectively nested with sealing rings. The top of the middle cylinder weld seam pressure testing body is fixed with a second lifting ring. The bottom of the middle cylinder weld seam pressure testing body is fixed with a liquid passage pipe. The liquid passage pipe passes through the top of the middle cylinder weld seam pressure testing body and is connected to a liquid filling joint.
[0011] Furthermore, both the outer cylinder weld seam test body and the middle cylinder weld seam test body are seamless tubes;
[0012] Furthermore, the outer cylinder testing baffle includes a first baffle fixed to the bottom inner wall of the outer cylinder weld test body and a second baffle fixed to the top inner wall of the outer cylinder weld test body;
[0013] Furthermore, both the first baffle and the second baffle are fixed in a ring shape;
[0014] Furthermore, both the first thread and the second thread are rectangular threads;
[0015] Furthermore, both the first and second lifting rings are symmetrically arranged;
[0016] Furthermore, the cylinder testing baffle includes a third baffle fixed to the bottom inner wall of the cylinder weld test body and a fourth baffle fixed to the top inner wall of the cylinder weld test body.
[0017] Furthermore, both the third and fourth baffles are fixed in a ring shape;
[0018] Furthermore, the liquid passage tube extends through the third baffle and the fourth baffle;
[0019] Furthermore, the liquid inlet tube and the liquid filling connector are fixed by U-shaped clips.
[0020] The above technical solution has the following advantages or beneficial effects:
[0021] This invention provides a defect detection device for weld seams in thin coal seam columns. Because deep holes are drilled in the walls of the outer and middle cylinders of the thin coal seam column, close to the narrow bottom of the weld seam, the gaps on the inner wall cannot be sealed. High-pressure liquid directly acts on the bottom of the narrow weld seam, making this area prone to processing defects that are difficult to inspect using existing non-destructive testing methods. By installing weld seam testing fixtures on the outer and middle cylinders respectively, weld quality can be inspected before assembly. This allows for early detection and repair of quality problems, avoiding the scrapping of parts due to irreparable defects after all processing is completed. This significantly improves work efficiency and reduces unnecessary time waste. The use of this weld seam defect detection device solves the problem of not being able to inspect welding quality using non-destructive testing methods, ensuring that the outer and middle cylinders meet design quality requirements before assembly. This helps improve production efficiency, reduces wear on seals during repeated disassembly and assembly, and improves product quality.
[0022] Furthermore, since the outer cylinder weld test body and the middle cylinder weld test body are made of seamless tubes, there are no welds or other potential defect sources inside. Therefore, when conducting weld test pressure, the quality of the weld to be tested can be evaluated more accurately. The structure of the seamless tube also reduces the test pressure error caused by internal material defects, thus improving the accuracy of the test.
[0023] Furthermore, the setting of the first and second baffles creates a closed testing space inside the outer cylinder weld pressure test body. During weld pressure testing, this closed space ensures that the test medium can fully contact the weld area to be tested, thereby achieving comprehensive testing of weld quality. This helps to discover potential weld defects such as cracks, slag inclusions, and lack of fusion, improving the accuracy and reliability of the test.
[0024] Furthermore, the annular fixed first and second baffles can fit tightly against the inner wall of the outer cylinder weld test body to form an effective sealing structure. The sealing not only helps to prevent the test medium from leaking during the test, but also ensures that the weld area is fully subjected to the action of the test medium, thereby improving the accuracy and reliability of weld inspection.
[0025] Furthermore, rectangular threads offer higher connection stability compared to other types of threads. Their larger tooth angle and deeper tooth depth generate greater friction and engagement force during connection, ensuring a tight connection between the outer cylinder weld test body and the middle cylinder weld test body or other connecting components, preventing leakage and loosening during the test.
[0026] Furthermore, the symmetrically arranged lifting rings ensure that the force on the weld seam pressure testing fixture is evenly distributed during the lifting process, which helps to prevent deformation or damage to the fixture due to uneven force, and ensures the safety and reliability of the lifting operation; it also makes the weld seam pressure testing fixture easier to install, reducing the difficulty and cost of installation.
[0027] Furthermore, the third and fourth baffles, together with the inner wall of the test body of the middle cylinder weld, form a closed testing space. The closed space ensures that the test medium can completely cover and act on the weld area, thereby improving the accuracy and reliability of weld testing. At the same time, the sealing also reduces medium leakage during the test process and ensures the stability of the testing environment.
[0028] Furthermore, the annularly fixed third and fourth baffles can fit tightly against the inner wall of the test body of the middle cylinder weld seam, forming an efficient sealing structure. The annular design allows the baffles to block the loss of the test medium in all directions, thereby improving the accuracy and reliability of the test.
[0029] Furthermore, the fluid passage pipe runs through the third and fourth baffles, ensuring that the test pressure medium can flow freely within the weld inspection area. This allows the test pressure medium to enter the weld inspection area more quickly and reach the required pressure level in a short time, which not only shortens the inspection time but also improves the accuracy and reliability of the inspection.
[0030] Furthermore, the U-shaped clamp can firmly fix the liquid inlet pipe and the liquid filling connector together, which can effectively prevent the connecting parts from falling off or being damaged due to excessive pressure, ensure the smooth flow of the test medium during the weld inspection process, and avoid leakage problems caused by loose connections. Attached Figure Description
[0031] Figure 1 This is a cross-sectional view of the outer cylinder weld pressure testing fixture of the thin coal seam column weld defect detection device of this utility model.
[0032] Figure 2 This is an assembly cross-sectional view of the outer cylinder weld pressure testing fixture of the thin coal seam column weld defect detection device of this utility model.
[0033] Figure 3 This is an assembly diagram of the outer cylinder weld pressure test fixture for a thin coal seam column weld defect detection device according to the present invention.
[0034] Figure 4 This is a cross-sectional view of the cylinder weld pressure testing fixture in the thin coal seam column weld defect detection device of this utility model.
[0035] Figure 5 This is an assembly cross-sectional view of the cylinder weld pressure testing fixture in a thin coal seam column weld defect detection device of this utility model.
[0036] Figure 6 This is a schematic diagram of the assembly of the cylinder weld pressure test fixture in the thin coal seam column weld defect detection device of this utility model.
[0037] In the diagram, 1-Outer cylinder weld seam test pressure body; 11-First baffle; 12-Second baffle; 13-First thread; 14-First sealing groove; 15-Sealing ring; 16-First lifting ring; 2-Middle cylinder weld seam test pressure body; 21-Third baffle; 22-Fourth baffle; 23-Second thread; 24-Second sealing groove; 25-Third sealing groove; 26-Second lifting ring; 27-Liquid pipe; 28-Liquid filling connector; 29-U-shaped clamp; 3-Outer cylinder; 4-Middle cylinder. Detailed Implementation
[0038] The present invention will be further described in detail below with reference to specific embodiments. The description is for explanation and not limitation of the present invention.
[0039] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention 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 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 should fall within the protection scope of the present invention.
[0040] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this utility model are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the utility model described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.
[0041] Example 1:
[0042] like Figure 3 and Figure 6 As shown, this utility model provides a thin coal seam column weld defect detection device, including an outer cylinder weld pressure testing fixture installed at the outer cylinder 3 port and a middle cylinder weld pressure testing fixture installed at the middle cylinder 4 port.
[0043] like Figure 1 and Figure 2 As shown, the outer cylinder weld pressure test fixture includes an outer cylinder weld pressure test body 1. The bottom inner wall and top inner wall of the outer cylinder weld pressure test body 1 are respectively fixed with an outer cylinder detection baffle. The top outer wall of the outer cylinder weld pressure test body 1 is provided with a first thread 13. The bottom outer wall of the outer cylinder weld pressure test body 1 is provided with a first sealing groove 14. A sealing ring 15 is nested in the first sealing groove 14. The top of the outer cylinder weld pressure test body 1 is fixed with a first lifting ring 16.
[0044] Preferably, the outer cylinder test baffle includes a first baffle 11 fixed to the bottom inner wall of the outer cylinder weld test body 1 and a second baffle 12 fixed to the top inner wall of the outer cylinder weld test body 1;
[0045] Preferably, both the first baffle 11 and the second baffle 12 are fixed in a ring shape.
[0046] like Figure 4 and Figure 5As shown, the cylinder weld pressure test fixture includes a cylinder weld pressure test body 2. The bottom inner wall and top inner wall of the cylinder weld pressure test body 2 are respectively fixed with a cylinder detection baffle in an annular shape. The top outer wall of the cylinder weld pressure test body 2 is provided with a second thread 23. The outer wall of the cylinder weld pressure test body 2 is provided with a second sealing groove 24 and a third sealing groove 25. The second sealing groove 24 and the third sealing groove 25 are respectively nested with sealing rings 15. The top of the cylinder weld pressure test body 2 is fixed with a second lifting ring 26. The bottom of the cylinder weld pressure test body 2 is fixed with a liquid passage pipe 27. The liquid passage pipe 27 passes through the top of the cylinder weld pressure test body 2 and is connected to a liquid filling connector 28.
[0047] Preferably, both the outer cylinder weld test body 1 and the middle cylinder weld test body 2 are seamless tubes;
[0048] Preferably, both the first thread 13 and the second thread 23 are rectangular threads;
[0049] Preferably, the first lifting ring 16 and the second lifting ring 26 are symmetrically arranged;
[0050] Preferably, the cylinder testing baffle includes a third baffle 21 fixed to the bottom inner wall of the cylinder weld test body 2 and a fourth baffle 22 fixed to the top inner wall of the cylinder weld test body 2.
[0051] Preferably, both the third baffle 21 and the fourth baffle 22 are fixed in a ring shape;
[0052] Preferably, the liquid passage 27 passes through the third baffle 21 and the fourth baffle 22;
[0053] Preferably, the liquid inlet tube 27 and the liquid filling connector 28 are fixed by a U-shaped clip 29.
[0054] Example 2:
[0055] like Figure 3 and Figure 6 As shown, this utility model provides a thin coal seam column weld defect detection device, including an outer cylinder weld pressure testing fixture installed at the outer cylinder 3 port and a middle cylinder weld pressure testing fixture installed at the middle cylinder 4 port.
[0056] like Figure 1 and Figure 2As shown, the outer cylinder weld pressure testing fixture includes an outer cylinder weld pressure testing body 1. Outer cylinder inspection baffles are fixed to the bottom inner wall and top inner wall of the outer cylinder weld pressure testing body 1, respectively. The outer cylinder inspection baffles include a first baffle 11, which is annularly welded and fixed to the bottom inner wall of the outer cylinder weld pressure testing body 1, and a second baffle 12, which is annularly welded and fixed to the top inner wall of the outer cylinder weld pressure testing body 1. This creates a closed inspection space inside the outer cylinder weld pressure testing body 1. During weld pressure testing, this closed space can ensure... The test pressure medium can fully contact the weld area to be tested, thereby achieving a comprehensive inspection of the weld quality. This helps to discover potential weld defects, such as cracks, slag inclusions, and lack of fusion, and improves the accuracy and reliability of the inspection. The top outer wall of the outer cylinder weld test body 1 is provided with a first thread 13, and the bottom outer wall of the outer cylinder weld test body 1 is provided with a first sealing groove 14. A sealing ring 15 is nested in the first sealing groove 14, and a first lifting ring 16 is fixed to the top of the outer cylinder weld test body 1.
[0057] like Figure 4 and Figure 5 As shown, the cylinder weld pressure testing fixture includes a cylinder weld pressure testing body 2. Cylinder inspection baffles are fixed to the bottom inner wall and top inner wall of the cylinder weld pressure testing body 2, respectively. The inspection baffles include a third baffle 21, which is annularly welded and fixed to the bottom inner wall of the cylinder weld pressure testing body 2, and a fourth baffle 22, which is annularly welded and fixed to the top inner wall of the cylinder weld pressure testing body 2. Together with the inner wall of the cylinder weld pressure testing body 2, they form a closed inspection space. This closed space ensures that the pressure testing medium can completely cover and act on the weld area, thereby improving the accuracy and reliability of weld inspection. Meanwhile, the sealing also reduces media leakage during the pressure test and ensures the stability of the testing environment; the top outer wall of the middle cylinder weld pressure test body 2 is provided with a second thread 23, the outer wall of the middle cylinder weld pressure test body 2 is provided with a second sealing groove 24 and a third sealing groove 25, and sealing rings 15 are nested in the second sealing groove 24 and the third sealing groove 25 respectively; the top of the middle cylinder weld pressure test body 2 is fixed with a second lifting ring 26, and the bottom of the middle cylinder weld pressure test body 2 is fixed with a liquid passage pipe 27, which passes through the top of the middle cylinder weld pressure test body 2 and is connected to a liquid filling connector 28;
[0058] Preferably, both the outer cylinder weld test body 1 and the middle cylinder weld test body 2 are seamless steel pipes, which can more accurately assess the quality of the weld to be tested, reduce test errors caused by internal material defects, and improve the accuracy of the test.
[0059] Preferably, the first thread 13 and the second thread 23 are both rectangular threads. Rectangular threads have higher connection stability than other types of threads. They have a large tooth profile angle and a deep tooth profile, which can generate greater friction and biting force during connection, thereby ensuring a tight connection between the outer cylinder weld test body and the middle cylinder weld test body or other connecting parts, and preventing leakage and loosening during the test.
[0060] Preferably, the first lifting ring 16 and the second lifting ring 26 are symmetrically arranged, which can ensure that the force on the weld seam pressure testing fixture is evenly distributed during the lifting process, which helps to prevent the fixture from deforming or being damaged due to uneven force, and ensures the safety and reliability of the lifting operation; it also makes the weld seam pressure testing fixture easier to install, reducing the difficulty and cost of installation.
[0061] Preferably, there are two first lifting rings 16 and two second lifting rings 26;
[0062] Preferably, the liquid passage 27 passes through the third baffle 21 and the fourth baffle 22, ensuring that the test pressure medium can flow freely in the weld inspection area, allowing the test pressure medium to enter the weld inspection area more quickly and reach the required pressure level in a short time, which not only shortens the inspection time but also improves the accuracy and reliability of the inspection.
[0063] Preferably, the liquid inlet pipe 27 and the liquid filling connector 28 are fixed by a U-shaped clip 29. The U-shaped clip 29 can firmly fix the liquid inlet pipe 27 and the liquid filling connector 28 together, which can effectively prevent the connecting parts from falling off or being damaged due to excessive pressure, ensure the smooth flow of the test medium during the weld inspection process, and avoid leakage problems caused by loose connection.
[0064] The working principle and production method of this utility model will be further explained below:
[0065] When using the thin coal seam column weld defect detection device provided by this utility model, such as Figure 3 As shown, the outer cylinder weld pressure test fixture is connected to the outer cylinder 3 through the first thread 13 to seal the outer cylinder port. The elbow joint at the safety valve is sealed with a pressure test plug. The pressure test plate is connected to the seat plate by bolts. Liquid is filled into the lower cavity of the cylinder. It is observed whether the liquid passage hole of the upper cavity leaks. If the liquid passage hole of the upper cavity leaks, it indicates that there is a defect in the weld between the seat plate surfaces. If the liquid passage hole of the upper cavity does not leak, it indicates that there is no defect in the weld between the seat plate surfaces.
[0066] like Figure 5 and Figure 6As shown, a bottom valve is installed at the bottom of the middle cylinder 4. The middle cylinder weld pressure test fixture is connected to the middle cylinder 4 through the second thread 23. The liquid filling connector 28 is connected to the liquid passage pipe 27 on the fixture and fixed by a U-shaped clamp. Liquid is filled into the middle cylinder 4. After the liquid is full, pressure is maintained. Observe whether there is leakage at the bottom valve and the liquid passage hole on the outer wall of the middle cylinder 4. If there is no leakage at the bottom valve hole and the liquid passage hole, it indicates that the bottom weld of the cylinder is sealed normally. If there is leakage at the bottom valve hole and the liquid passage hole, it indicates that there is a defect at the bottom weld of the cylinder.
[0067] In the production of the thin coal seam column weld defect detection device provided by this utility model, the outer cylinder weld test body 1 is selected as a seamless steel pipe. The first baffle 11 is inserted into the bottom inner wall of the seamless steel pipe and the first baffle 11 is welded together with the bottom inner wall of the seamless steel pipe by welding. The second baffle 12 is inserted into the top inner wall of the seamless steel pipe and the second baffle 12 is welded together with the top inner wall of the seamless steel pipe by welding. Then, a rectangular first thread 13 and a first sealing groove 14 of the inner wall stroke section are processed on the outer wall of the seamless steel pipe. Two first lifting rings 16 are symmetrically welded on one side of the rectangular first thread 13. The sealing ring 15 is nested in the first sealing groove 14 to complete the production of the outer cylinder weld test fixture.
[0068] The test body 2 of the middle cylinder weld is selected as a seamless steel pipe. The liquid passage pipe 27 is connected to the liquid filling joint 28 and inserted into the third baffle 21 and the fourth baffle 22. The third baffle 21 and the liquid passage pipe 27 are fixed together by welding. The fourth baffle 22 and the liquid passage pipe 27 are fixed together by welding. The liquid passage pipe 27 component with baffles is inserted into the inner wall of the seamless steel pipe as a whole. The third baffle 21 is fixed to the bottom inner wall of the seamless steel pipe by welding. Similarly, the fourth baffle 22 is fixed to the top inner wall of the seamless steel pipe by welding. Then, a rectangular second thread 23, a second sealing groove 24 for the inner wall stroke section, and a third sealing groove 25 for the static sealing part are processed on the outer wall of the seamless steel pipe. Then, two second lifting rings 26 are symmetrically welded to the liquid filling joint 28. The sealing rings 15 are nested in the second sealing groove 24 and the third sealing groove 25 in sequence.
[0069] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and not to limit it; although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model.
Claims
1. A device for detecting defects in weld seams of pillars in thin coal seams, characterized in that, Including the outer cylinder weld pressure test fixture installed at the cylinder port of the outer cylinder (3) and the middle cylinder weld pressure test fixture installed at the cylinder port of the middle cylinder (4); The outer cylinder weld pressure test fixture includes an outer cylinder weld pressure test body (1), with an outer cylinder test baffle fixed to the bottom inner wall and top inner wall of the outer cylinder weld pressure test body (1), a first thread (13) provided on the top outer wall of the outer cylinder weld pressure test body (1), a first sealing groove (14) provided on the bottom outer wall of the outer cylinder weld pressure test body (1), a sealing ring (15) nested in the first sealing groove (14), and a first lifting ring (16) fixed to the top of the outer cylinder weld pressure test body (1). The pressure testing fixture for the middle cylinder weld seam includes a pressure testing body (2) for the middle cylinder weld seam. The bottom inner wall and the top inner wall of the pressure testing body (2) are respectively fixed with a middle cylinder detection baffle. The top outer wall of the pressure testing body (2) is provided with a second thread (23). The outer wall of the pressure testing body (2) is provided with a second sealing groove (24) and a third sealing groove (25). The second sealing groove (24) and the third sealing groove (25) are respectively nested with sealing rings (15). The top of the pressure testing body (2) is fixed with a second lifting ring (26). The bottom of the pressure testing body (2) is fixed with a liquid passage pipe (27). The liquid passage pipe (27) passes through the top of the pressure testing body (2) and is connected to a liquid filling connector (28).
2. The thin coal seam column weld defect detection device according to claim 1, characterized in that, Both the outer cylinder weld test body (1) and the middle cylinder weld test body (2) are seamless pipes.
3. The thin coal seam column weld defect detection device according to claim 1, characterized in that, The outer cylinder test baffle includes a first baffle (11) fixed to the bottom inner wall of the outer cylinder weld test body (1) and a second baffle (12) fixed to the top inner wall of the outer cylinder weld test body (1).
4. The thin coal seam column weld defect detection device according to claim 3, characterized in that, The first baffle (11) and the second baffle (12) are both fixed in a ring shape.
5. The thin coal seam column weld defect detection device according to claim 1, characterized in that, Both the first thread (13) and the second thread (23) are rectangular threads.
6. The thin coal seam column weld defect detection device according to claim 1, characterized in that, The first lifting ring (16) and the second lifting ring (26) are symmetrically arranged.
7. The thin coal seam column weld defect detection device according to claim 1, characterized in that, The cylinder testing baffle includes a third baffle (21) fixed to the bottom inner wall of the cylinder weld test body (2) and a fourth baffle (22) fixed to the top inner wall of the cylinder weld test body (2).
8. The thin coal seam column weld defect detection device according to claim 7, characterized in that, The third baffle (21) and the fourth baffle (22) are both fixed in a ring shape.
9. A thin coal seam column weld defect detection device according to claim 7, characterized in that, The liquid inlet tube (27) passes through the third baffle (21) and the fourth baffle (22).
10. A thin coal seam column weld defect detection device according to claim 1, characterized in that, The liquid inlet tube (27) and the liquid filling connector (28) are fixed by a U-shaped clip (29).