A fastening detection device for steel structure engineering

Abstract

The application relates to the technical field of steel structure engineering and discloses a fastening detection equipment for steel structure engineering, which aims to solve the problem that the detection position of a steel plate changes, thereby affecting the accuracy of detection data. The extension edge is arranged with the moving mechanism, the extension edge is used for limiting the front and back positions of the steel plate, the contact plate is used for limiting the left and right positions of the steel plate, the detection position of the steel plate is opposite to the pressing mechanism, and therefore the accuracy of detection data is avoided from being affected.

Description

Technical Field

[0001] This application relates to the field of steel structure engineering technology, and in particular to a fastening testing device for steel structure engineering. Background Technology

[0002] In today's technologically advanced society, steel structures have been applied in various familiar locations. Among them, the most well-known application of steel structures is in various construction projects. In order to ensure the tightness of steel structures, welding or connection between steel structures is often required before use. Since the strength of the connection needs to be randomly checked to ensure that the project meets the requirements, a fastening testing device is needed to test the strength of the connection of the steel structure.

[0003] In some existing steel materials (such as two steel plates welded together, hereinafter referred to as steel plates), the steel plates are first placed on symmetrical support cylinders. Then, a pressure plate above the steel plates presses down on the middle position (welding position) of the steel, causing the middle part of the steel plate to bend downwards and the two ends to bend upwards. The pressure plate is connected to a pressure sensor, and a laser sensor is set at the middle position below the steel plate. The laser sensor senses the amount of bending of the steel plate, and the pressure sensor senses the force required for the steel plate to bend to a specified angle. Based on the obtained data, the welding quality of the steel is judged to be qualified (or as in the equipment in application number 202420570010.8).

[0004] However, during the placement of the steel plate, the lack of a limiting device causes the middle position of the steel plate to easily deviate from the pressing component when it is placed on the supporting rotating cylinder, resulting in a change in the detection position of the steel plate and thus affecting the accuracy of the detection data. Summary of the Invention

[0005] This application proposes a fastening testing device for steel structure engineering, which has the advantage of limiting the position of the steel plate, thereby solving the problem that changes in the testing position of the steel plate affect the accuracy of the testing data.

[0006] To achieve the above objectives, this application adopts the following technical solution: a fastening testing device for steel structure engineering, comprising: a worktable at upper and lower positions, a mounting top plate, and side support plates at both sides, wherein the worktable, mounting top plate, and side support plates together form a working space; mounting seats are symmetrically installed on the upper side of the worktable within the working space; a lower rotating cylinder is rotatably mounted on the upper end of the mounting seat; a steel plate is placed on the upper side of the lower rotating cylinder; a top electric cylinder is fixedly installed at the middle position of the mounting top plate; a pressing mechanism is installed at the lower end of the telescopic rod of the top electric cylinder; the pressing mechanism... The system includes a pressure sensor, which is fixedly installed at the end of the telescopic rod of the top electric cylinder. A laser sensor is fixedly installed at the middle position of the side of the worktable. Both ends of the lower rotating cylinder are fixedly installed with extension edges. The opposite sides of the two extension edges form sliding contact with the corresponding sides of the steel plate. A moving mechanism is provided inside the side support plate. The moving mechanism includes a side electric cylinder and a contact plate. The side electric cylinder is fixedly installed inside the side support plate. The contact plate is located between the side support plate and the mounting base. The telescopic rod of the side electric cylinder is fixedly connected to the contact plate.

[0007] Furthermore, the moving mechanism also includes: A connecting plate is provided, with a contact plate and a mounting base fixedly connected to both sides of the connecting plate respectively. A sliding groove is provided on the upper side of the worktable, located between the laser sensor and the side support plate. The lower end of the mounting base is slidably engaged with the sliding groove.

[0008] Furthermore, the pressing mechanism also includes: The rotary table is located below the top electric cylinder; Press the rotating drum and rotate it to the lower side of the rotating drum platform. The middle position of the upper side of the rotating drum platform corresponds to the pressure sensor inside the top electric cylinder. The mounting brackets are fixedly installed on both sides of the rotating drum platform. The slot is formed on the arc-shaped side of the end of the telescopic rod of the top electric cylinder, and the locking block of the locking seat and the slot are engaged in a sliding engagement.

[0009] Furthermore, a No. 1 rotating platform is fixedly installed on one side of the lower rotating cylinder in the axial direction. Through holes are opened horizontally on both the upper and lower sides of the contact plate. A fixed pulley is fixedly installed on the side of the contact plate facing away from the No. 1 rotating platform and corresponding to the position of the through hole. A No. 1 lower hole is opened on the circumferential side of the No. 1 rotating platform for fixing one end of the No. 1 cable. The other end of the No. 1 cable passes through the lower through hole of the contact plate in the corresponding direction in sequence, and is guided by the lower fixed pulley and the upper fixed pulley, and then extends out from the upper through hole. A No. 1 upper hole is opened on the arc-shaped side of the top electric cylinder, and the other end of the No. 1 cable is fixedly connected to the No. 1 upper hole.

[0010] Furthermore, a second rotating platform is fixedly installed on the other side of the lower rotating drum in the axial direction. The second rotating platform has a second lower hole on its circumferential side for fixing one end of the second cable. The rotating drum platform has a second upper hole on its corresponding side, and the other end of the second cable is fixedly connected to the second upper hole.

[0011] Furthermore, when the steel plate is bent to a specified angle, the lowest point of the bent part of the steel plate is higher than the lowest point of the circumferential side of the second rotating platform.

[0012] Furthermore, both the No. 1 and No. 2 cables are made of low-relaxation, high-strength galvanized steel wire, and baffles are provided on both sides of the fixed pulley in the axial direction.

[0013] Furthermore, cable heads are rotatably mounted at the ends of both the first and second cables. The cable heads are strong magnets, and strong magnets that attract opposite poles to the cable heads are installed inside the first lower hole, the first upper hole, the second lower hole, and the second upper hole.

[0014] This application has the following beneficial effects: This application provides a fastening testing device for steel structure engineering. By setting an extension edge and a moving mechanism, the extension edge restricts the front-to-back position of the steel plate, and the contact plate restricts the left-to-right position of the steel plate, so that the testing position of the steel plate corresponds to the pressing mechanism, thereby avoiding the impact on the accuracy of the testing data.

[0015] By setting up the lower rotating drum, the first rotating platform, and the first cable, the vertical downward motion of the pressing mechanism is converted into the active rotation of the lower rotating drum through the unidirectional transmission of the first cable. Moreover, the rotation direction of the lower rotating drum is completely consistent with the sliding direction when the steel plate is bent, which fundamentally eliminates the sliding friction resistance of the support point and reduces the detection error of the pressure sensor. Attached Figure Description

[0016] The accompanying drawings, which form part of this specification, illustrate embodiments disclosed in this application and, together with the specification, serve to explain the principles disclosed in this application.

[0017] This application can be more clearly understood with reference to the accompanying drawings and the following detailed description, wherein: Figure 1 This is a schematic diagram of the working state of the present invention; Figure 2 This is a schematic diagram showing the connection state between the moving mechanism and the mounting base of the present invention; Figure 3 This is a schematic diagram of the mounting base of the present invention; Figure 4 This is a schematic diagram of the connection structure at both ends of the lower rotating drum of the present invention; Figure 5This is a schematic diagram of the composition of the pressing mechanism of the present invention; Figure 6 This is a schematic diagram of the end mounting structure of the telescopic rod of the top electric cylinder of the present invention; Figure 7 This is a schematic diagram showing the connection state between the No. 1 cable and the cable head of the present invention.

[0018] In the diagram: 1. Workbench; 2. Mounting top plate; 3. Side support plate; 4. Mounting base; 5. Lower rotating drum; 6. Steel plate; 7. Top electric cylinder; 8. Pressing mechanism; 80. Pressure sensor; 81. Rotating drum platform; 82. Pressing rotating drum; 83. Card seat; 84. Card slot; 9. Laser sensor; 10. Extension edge; 11. Moving mechanism; 110. Side electric cylinder; 111. Contact plate; 112. Connecting plate; 12. Slide groove; 13. No. 1 rotating platform; 14. Through hole; 15. Fixed pulley; 16. No. 1 lower hole; 17. No. 1 cable; 18. No. 1 upper hole; 19. No. 2 rotating platform; 20. No. 2 lower hole; 21. No. 2 cable; 22. No. 2 upper hole; 23. Cable head. Detailed Implementation

[0019] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0020] Example 1: Please refer to Figures 1-7A fastening testing device for steel structure engineering includes a workbench 1, a mounting top plate 2 above the workbench 1, and two side support plates 3 on either side of the workbench 1 facing each other. The workbench 1, the mounting top plate 2, and the two side support plates 3 together form a working space. Mounting seats 4 are symmetrically installed on the upper side of the workbench 1 within the working space. A lower rotating cylinder 5 is rotatably mounted on the upper end of the mounting seat 4, and a steel plate 6 is placed on the upper side of the lower rotating cylinder 5. A top electric cylinder 7 is fixedly installed in the middle of the mounting top plate 2. The lower end of the telescopic rod of the top electric cylinder 7 extends into the working space, and a pressing mechanism 8 is installed at the lower end of the telescopic rod of the top electric cylinder 7. The structure 8 includes a pressure sensor 80, which is fixedly installed at the end of the telescopic rod of the top electric cylinder 7. A laser sensor 9 is fixedly installed at the middle position of the upper side of the worktable 1. Both ends of the lower rotating cylinder 5 are fixedly installed with extension edges 10. The opposite sides of the two extension edges 10 form a sliding contact with the corresponding sides of the steel plate 6. A moving mechanism 11 is provided inside the side support plate 3. The moving mechanism 11 includes a side electric cylinder 110 and a contact plate 111. The side electric cylinder 110 is fixedly installed inside the side support plate 3. The contact plate 111 is located between the side support plate 3 and the mounting base 4. The telescopic rod of the side electric cylinder 110 is fixedly connected to the contact plate 111.

[0021] In use, first place the steel plate 6 on the left and right lower rotating cylinders 5 and position the steel plate 6 between the corresponding extension edges 10. Use the extension edges 10 to restrict the front and back position of the steel plate 6. Then, make the side electric cylinder 110 drive the contact plate 111 to move the same distance, and then contact the left and right positions of the steel plate 6, and make the steel plate 6 directly correspond to the pressing mechanism 8. Through the above actions, the accuracy of the detection data is avoided. Then, the telescopic rod of the top electric cylinder 7 is extended, which drives the pressing mechanism 8 to move down, so that the pressing mechanism 8 presses down on the middle position of the steel plate 6, causing the middle part of the steel plate 6 to bend downward and the two ends to bend upward. The amount of bending of the steel plate 6 is detected by the laser sensor 9 located below the steel plate 6 (the shorter the detection distance of the laser, the greater the bending amount). The pressure sensor 80 senses the force required for the steel plate 6 to bend to the specified angle, and then judges whether the finished steel product is qualified based on the obtained data. After the test is completed, the top electric cylinder 7 drives the pressing mechanism 8 to reset, then the bent steel plate 6 is removed, and the side electric cylinder 110 drives the contact plate 111 to reset.

[0022] Please see Figures 1-7 The moving mechanism 11 also includes a connecting plate 112. The two sides of the connecting plate 112 are respectively fixedly connected to the contact plate 111 and the mounting base 4. The upper side of the worktable 1 and the position between the laser sensor 9 and the side support plate 3 are provided with sliding grooves 12. The lower end of the mounting base 4 is slidably engaged with the sliding grooves 12.

[0023] The contact plate 111 is integrally connected to the mounting base 4 by the connecting plate 112. After the steel plate 6 is placed on the lower rotating cylinder 5, the side electric cylinder 110 drives the contact plate and the lower rotating cylinder 5 to move synchronously. This achieves the simultaneous completion of the centering of the end of the steel plate 6 and the automatic adjustment of the support spacing of the lower rotating cylinder 5 in one action, completely eliminating the additional bending moment error caused by the asymmetry of the support. It automatically adapts to steel plate 6 samples of different lengths without the need for manual parameter adjustment.

[0024] Please see Figures 1-7 The pressing mechanism 8 also includes a rotating platform 81, a pressing rotating cylinder 82, a card seat 83, and a card slot 84. The rotating platform 81 is located below the top electric cylinder 7. The pressing rotating cylinder 82 (rotating via a bearing) is rotatably installed on the lower side inside the rotating platform 81. The middle position of the upper side of the rotating platform 81 corresponds to the pressure sensor 80 inside the top electric cylinder 7. Card seats 83 are fixedly installed on both sides of the upper side of the rotating platform 81. Card slots 84 are symmetrically opened on the arc-shaped side of the end of the telescopic rod of the top electric cylinder 7. The card block of the card seat 83 and the card slot 84 form an up-and-down sliding engagement.

[0025] During the process of the electric cylinder 7 driving the pressing mechanism 8 to press down the steel plate 6, the pressing cylinder 82 will contact and press down the steel plate 6, causing the cylinder platform 81 to contact the pressure sensor 80, thereby causing the pressure sensor 80 to sense the force required to bend the steel plate 6 to a specified angle, and then judging whether the finished steel product is qualified based on the obtained data. At the same time, the rolling friction generated by the passively rotating pressing cylinder 82 replaces the sliding friction of the existing pressing parts, reducing the error of the pressure sensor 80 measurement value (the existing pressing parts (such as pressure blocks) and steel plate 6 are in line contact sliding friction: when bending, the upper surface of steel plate 6 is compressed and will slide inward relative to the pressing parts, generating frictional resistance opposite to the loading direction. This frictional resistance will be directly measured by the pressure sensor 80, which usually brings 2%-6% system error, and increases with the increase of the thickness and hardness of steel plate 6). Initial state: The flat steel plate 6 and the pressing part are indeed in small-area surface contact; After bending begins: The upper surface of the steel plate 6 is pressed into an arc surface, while the pressing part is always a plane. Geometrically, a plane and an arc surface can only have one common tangent, which is theoretically a line contact. When any material is bent, there is a neutral layer inside. The length of the neutral layer remains unchanged before and after bending. The part above the neutral layer (upper surface) is compressed and shortened in length, while the part below the neutral layer (lower surface) is stretched and lengthened. In other words, during the bending process, the total length of the upper surface of the steel plate 6 is shortened, while the pressing component is fixed (it only moves vertically downwards and not horizontally). Therefore, the shortened length can only be achieved by the upper surface of the steel plate 6 sliding towards the center relative to the pressing component. The sliding direction is: all points on the upper surface of the steel plate 6 slide towards the bending center (that is, directly below the pressing component) relative to the pressing component. Although the frictional force is horizontal, it will generate a vertical component force through the inclination angle of the contact point, which is directly superimposed on the measurement value of the pressure sensor 80. Precise force decomposition: When the steel plate 6 bends, an angle θ (θ≈ half of the bending angle) will be formed between the surface of the steel plate 6 at the contact point and the horizontal plane. At this time, the pressing part is subjected to three forces: the downward thrust F of the top electric cylinder 7 (equal to the measurement value of the pressure sensor 80), the normal force N of the steel plate 6 on the pressing part: the direction is perpendicular to the surface of the steel plate 6 (tilted upward), and the sliding friction force f of the steel plate 6 on the pressing part: the direction is upward along the surface of the steel plate 6 (resisting the steel plate from sliding towards the middle). Decompose N and f into vertical and horizontal components: vertical component: Ncosθ + fsinθ, horizontal component: Nsinθ - fcosθ. According to the equilibrium of forces, the resultant force in the vertical direction is zero: F = Ncosθ + fsinθ. The actual bending force of the steel plate 6 should be the vertical component when there is no friction, that is: Factual = Ncosθ. Therefore, the error between the measured value and the actual value of the pressure sensor 80 is: ΔF = fsinθ. This is the source of the error: the vertical component of the friction force is treated by the pressure sensor 80 as the bending resistance of the steel plate 6. Why does the error increase as the steel plate 6 becomes thicker? The thicker the steel plate 6, the larger the radius of curvature R is under the same bending angle, and the larger the inclination angle θ of the contact point is: θ≈L / (2R)≈αt / (2L). When the thickness t is doubled, the inclination angle θ is approximately doubled, tanθ is also approximately doubled, and the error rate is also approximately doubled. Why does the error increase as steel plate 6 becomes harder? The higher the hardness of steel plate 6, the higher its yield strength, and the greater the normal force N required for bending. Frictional force f=μN is proportional to normal force. Although the error rate μtanθ remains unchanged, the absolute error ΔF=μNsinθ will increase linearly with N. Why does replacing it with a pressing rotary cylinder 82 completely solve this problem? If the fixed flat pressing component is replaced with a freely rotating pressing rotary cylinder 82, the contact method changes from sliding friction to rolling friction. The rolling friction coefficient μroll ≈ 0.001-0.005, which is two orders of magnitude smaller than the sliding friction coefficient. Substituting this into the error rate formula: Error rate = μroll tanθ ≈ 0.001 × 0.2 ≈ 0.02%. This error is much smaller than the error of the pressure sensor 80 itself (0.1%~0.5%), and can be completely ignored. Moreover, the pressing cylinder 82 will automatically rotate as the steel plate 6 bends (although the frictional forces applied to the pressing cylinder 82 by the two sides of the bent steel plate 6 are symmetrical and opposite, in reality, the frictional forces applied to the pressing cylinder 82 by the two sides of the bent position of the steel plate 6 will not be completely balanced, thus causing the side with greater friction to drive the pressing cylinder 82 to roll passively). There is no relative sliding between the upper surface of the steel plate 6 and the pressing cylinder 82, eliminating this source of error from the root.

[0026] Example 2: Please refer to Figures 1-7 A rotating platform 13 is fixedly installed on one side of the lower rotating cylinder 5 in the axial direction. Through holes 14 are horizontally opened on both the upper and lower sides of the contact plate 111. A fixed pulley 15 is fixedly installed on the side of the contact plate 111 facing away from the rotating platform 13 and corresponding to the position of the through hole 14. A lower hole 16 is opened on the circumferential side of the rotating platform 13. (A torsion spring is installed inside the rotating platform 13, and the other end of the torsion spring is connected to the inner wall of the annular part of the mounting base 4, so that...) When no external force is applied, the No. 1 rotating platform 13 on both sides drives the No. 1 lower hole position 16 to be opposite each other, which is used to fix one end of the No. 1 cable 17. The other end of the No. 1 cable 17 passes through the lower through hole 14 of the corresponding direction contact plate 111 in sequence, and is guided by the lower fixed pulley 15 and the upper fixed pulley 15, and then extends out from the upper through hole 14. The arc-shaped side of the top electric cylinder 7 is provided with a No. 1 upper hole position 18, and the other end of the No. 1 cable 17 is fixedly connected to the No. 1 upper hole position 18.

[0027] After the top electric cylinder 7 drives the pressing drum 82 to contact the upper side of the steel plate 6, the top electric cylinder 7 temporarily stops operating (at this time, the pressing drum 82 does not press down on the steel plate 6). Then, the two ends of the first cable 17 are fixedly connected to the first lower hole 16 and the first upper hole 18 respectively. At this time, the first cable 17 is in a slightly tensioned state. Then, the top electric cylinder 7 runs again, causing the pressing drum 82 to press down on the steel plate 6, and the drum platform 81 is subjected to a reverse force, which in turn contacts the pressure sensor 80, causing the pressure sensor 80 to start detection. During this process, the extension rod of the top electric cylinder 7 will pull the first cable 17, causing the first cable 17 to drive the corresponding first rotating platform 13 to rotate (left). The rotation directions of the No. 1 rotating platforms 13 on both sides are opposite, and both face the bending direction of the steel plate 6, causing the corresponding lower rotating drum 5 to rotate synchronously. Through the above actions, the vertical downward movement of the telescopic rod of the top electric cylinder 7 is converted into the active rotation of the lower rotating drum 5, and the rotation direction of the lower rotating drum 5 is completely consistent with the sliding direction when the steel plate 6 is bent, fundamentally eliminating the sliding friction resistance of the support point and reducing the detection error of the pressure sensor 80 (when the pressing rotating drum 82 presses down on the steel plate 6, the steel plate 6 will change from a straight state to a bent state, causing the two ends of the steel plate 6 to slide inward. Theoretically, if the lower rotating drum 5 can rotate perfectly synchronously, the steel plate 6 and the lower rotating drum 5 should roll purely). While there is no friction, the passively rotating lower drum 5 can never achieve perfect synchronization for two reasons: First, the lower drum 5 has rotational inertia: it needs an acceleration process from rest to rotation, which cannot keep up with the instantaneous deformation speed of the steel plate 6. Second, the bearings of the lower drum 5 have frictional resistance: any bearing has rolling friction and sealing friction, which will hinder the rotation of the lower drum 5. The combination of these two factors results in: the steel plate 6 has already begun to slide inward, but the lower drum 5 has not yet started rotating, or rotates slower than the steel plate 6. Therefore, relative sliding occurs between the surfaces of the steel plate 6 and the lower drum 5, which is the sliding frictional resistance mentioned above. The pressure sensor 80 displays the force = the force that actually causes the steel plate 6 to bend + The force to overcome the sliding friction of the left lower rotating drum 5 plus the force to overcome the sliding friction of the right lower rotating drum 5. If the bearing is rusty, poorly lubricated, or the surface of the steel plate 6 is rough, the frictional resistance will be even greater, and the error can even reach more than 30%. Therefore, the core logic of the above-mentioned No. 1 cable 17 actively pulling the lower rotating drum 5 to rotate is to make the rotation speed of the lower rotating drum 5 slightly faster than the sliding speed of the steel plate 6. In this way, there will be no relative sliding between the steel plate 6 and the lower rotating drum 5, but rather a slight "rolling tendency". The frictional resistance changes from the force that hinders the sliding of the steel plate 6 to the force that pushes the steel plate 6 to slide. At this time, the force value measured by the pressure sensor 80 is almost equal to the actual bending force of the steel plate 6. After the test is completed, the telescopic rod of the top electric cylinder 7 drives the pressing mechanism 8 to move upward and reset, so that the first cable 17 is gradually relaxed, and the torsion spring in the first rotating platform 13 drives it and the lower rotating cylinder 5 to rotate and reset. Then, the first cable 17 and the bent steel plate 6 are removed, and the side electric cylinder 110 drives the contact plate 111 and the lower rotating cylinder 5 to reset.

[0028] Example 3: Please refer to Figures 1-7 A second rotating platform 19 is fixedly installed on the other side of the lower rotating drum 5 in the axial direction. A second lower hole 20 is opened on the circumferential side of the second rotating platform 19 for fixing one end of the second cable 21. A second upper hole 22 is opened on the side of the rotating drum platform 81 in the corresponding direction. The other end of the second cable 21 is fixedly connected to the second upper hole 22. When the steel plate 6 is bent to a specified angle, the lowest position of the bent part of the steel plate 6 is higher than the lowest point of the circumferential side of the second rotating platform 19.

[0029] During the process of the first cable 17 pulling the lower rotating drum 5 to rotate, the lower rotating drum 5 will drive the second rotating platform 19 to rotate synchronously, so that the second cable 21 applies a downward pulling force to the rotating drum platform 81, causing the rotating drum platform 81 to first drive the pressing rotating drum 82 to press against the upper surface of the steel plate 6. This ensures that when the steel plate 6 bends and deforms subsequently, the pressing rotating drum 82 responds instantly by rotating, avoiding sliding friction between the pressing rotating drum 82 and the steel plate, which would affect the detection value of the pressure sensor 80. (The pressing rotating drum 82 and the rotating drum platform 81 are rotated through rolling bearings.) A small clearance (called radial clearance) must be maintained between the inner ring, outer ring, and rolling elements of a rolling bearing; otherwise, the bearing will seize and become unable to rotate. This clearance is typically only 0.01-0.05 mm, but it can still affect the measurement values ​​of the pressure sensor 80 in a bending test. When the steel plate 6 begins to deform and attempts to rotate the pressing cylinder 82, it first needs to complete the idle stroke of this bearing clearance. During the idle stroke, the pressing cylinder 82 remains completely still, and relative sliding occurs between the steel plate 6 and the pressing cylinder 82. The pressing drum 82 will only start rotating after the gap has been cleared. This lag process generates sliding friction. The static friction force that an object needs to overcome to move from rest is 3-10 times the dynamic friction force after it has started moving. When the pressing drum 82 is stationary, the static friction torque of the bearing is approximately 0.01-0.05 N·m. When the torque applied by the steel plate 6 is less than this value, the pressing drum 82 remains stationary, and sliding occurs between them. Only when the torque applied by the steel plate 6 exceeds the static friction torque will the pressing drum 82 suddenly start rotating. The process of sliding and then rotating will produce a significant peak on the force curve, leading to measurement errors. The function of the second cable 21 is to eliminate bearing clearance by applying a preload torque: this torque will cause the inner ring of the bearing in the pressing cylinder 82 to deflect slightly relative to the outer ring. This deflection will press the rolling elements on one side of the bearing tightly onto the raceway, completely eliminating the radial clearance of the bearing. At this time, the bearing is in a zero-clearance state with no free stroke. As long as there is a slight tendency to rotate, the pressing cylinder 82 will respond immediately.

[0030] Please see Figures 1-7 Both cable 17 and cable 21 are made of low-relaxation high-strength galvanized steel wire (1860–2000MPa grade), and baffles are provided on both sides of the fixed pulley 15 in the axial direction.

[0031] By using low-relaxation, high-strength galvanized steel wire, the torque does not decay under long-term tension, with a relaxation rate of ≤2.5% after 1000 hours, ensuring a constant preload torque over a long period. A small diameter provides sufficient preload, reducing space requirements, and the wire has a strength ≥1860MPa. It exhibits minimal deformation and high stiffness, with stable elongation after preload, preventing torque fluctuations caused by "softness." It remains unbroken and does not loosen under long-term reciprocating micro-deformation. Temperature and humidity have minimal impact, resulting in minimal torque drift.

[0032] Please see Figures 1-7 Both cable 17 and cable 21 are rotatably mounted with cable heads 23. Cable heads 23 are strong magnets (or have threads on their surfaces). The lower hole 16, the upper hole 18, the lower hole 20, and the upper hole 22 are all equipped with strong magnets that attract opposite poles to the cable heads 23 (or have threads that match the threads on the surface of the cable heads 23).

[0033] The cable head 23 enables quick disassembly of cable 17 and cable 21.

Claims

1. A fastening testing device for steel structure engineering, comprising: The workbench (1) at the top and bottom, the mounting top plate (2), and the side support plates (3) on both sides together form a working space. A mounting base (4) is symmetrically installed on the upper side of the workbench (1) within the working space. A lower rotating cylinder (5) is rotatably mounted on the upper end of the mounting base (4). A steel plate (6) is placed on the upper side of the lower rotating cylinder (5). A top electric cylinder (7) is fixedly installed in the middle of the mounting top plate (2). A telescopic rod of the top electric cylinder (7) is fitted with a... The pressing mechanism (8) includes a pressure sensor (80), which is fixedly installed at the end of the telescopic rod of the top electric cylinder (7). A laser sensor (9) is fixedly installed at the middle position of the upper side of the workbench (1). The lower rotating cylinder (5) has extension edges (10) fixedly installed at both ends. The sides of the two extension edges (10) that are opposite to each other form a sliding contact with the side of the steel plate (6). The side support plate (3) is provided with a moving mechanism (11). The moving mechanism (11) includes: A side electric cylinder (110) is fixedly installed inside the side support plate (3); The contact plate (111) is located between the side support plate (3) and the mounting base (4), and the telescopic rod of the side electric cylinder (110) is fixedly connected to the contact plate (111).

2. The fastening testing equipment for steel structure engineering according to claim 1, characterized in that, The moving mechanism (11) also includes: The connecting plate (112) has a contact plate (111) and a mounting base (4) fixedly connected on both sides. The upper side of the workbench (1) and the position between the laser sensor (9) and the side support plate (3) are provided with a sliding groove (12). The lower end of the mounting base (4) is slidably engaged with the sliding groove (12).

3. The fastening testing equipment for steel structure engineering according to claim 2, characterized in that, The pressing mechanism (8) further includes: The rotary table (81) is located below the top electric cylinder (7); Press the rotating drum (82) and rotate it to the lower side of the rotating drum platform (81). The middle position of the upper side of the rotating drum platform (81) corresponds to the pressure sensor (80) inside the top electric cylinder (7). The card holder (83) is fixedly installed on both sides of the upper side of the rotary table (81); The slot (84) is opened on the arc-shaped side of the end of the telescopic rod of the top electric cylinder (7), and the card block of the card seat (83) and the slot (84) form an up-and-down sliding engagement.

4. The fastening testing equipment for steel structure engineering according to claim 3, characterized in that, A rotating platform (13) is fixedly installed on one side of the lower rotating cylinder (5) in the axial direction. Through holes (14) are opened horizontally on both the upper and lower sides of the contact plate (111). A fixed pulley (15) is fixedly installed on the side of the contact plate (111) facing away from the rotating platform (13) and corresponding to the position of the through hole (14). A lower hole (16) is opened on the circumferential side of the rotating platform (13) to fix one end of the cable (17). The other end of the cable (17) passes through the lower through hole (14) of the contact plate (111) in the corresponding direction, and is guided by the lower fixed pulley (15) and the upper fixed pulley (15) to extend out from the upper through hole (14). A upper hole (18) is opened on the arc-shaped side of the top electric cylinder (7). The other end of the cable (17) is fixedly connected to the upper hole (18).

5. A fastening testing device for steel structure engineering according to claim 4, characterized in that, A second rotating platform (19) is fixedly installed on the other side of the lower rotating drum (5) in the axial direction. A second lower hole (20) is opened on the circumferential side of the second rotating platform (19) for fixing one end of the second cable (21). A second upper hole (22) is opened on the side of the rotating drum platform (81) in the corresponding direction. The other end of the second cable (21) is fixedly connected to the second upper hole (22).

6. The fastening testing equipment for steel structure engineering according to claim 5, characterized in that, When the steel plate (6) is bent to a specified angle, the lowest position of the bent part of the steel plate (6) is higher than the lowest point of the circumferential side of the second rotating platform (19).

7. A fastening testing device for steel structure engineering according to claim 5, characterized in that, Both the No. 1 cable (17) and the No. 2 cable (21) are made of low-relaxation high-strength galvanized steel wire, and baffles are provided on both sides of the fixed pulley (15) in the axial direction.

8. A fastening testing device for steel structure engineering according to claim 5, characterized in that, Both the first cable (17) and the second cable (21) are rotatably equipped with cable heads (23). The cable heads (23) are strong magnets. The first lower hole (16), the first upper hole (18), the second lower hole (20), and the second upper hole (22) are all equipped with strong magnets that attract the opposite poles of the cable heads (23).

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