A center drill pipe short section connection strength detection device

Abstract

This invention relates to the field of drill bit testing equipment technology, and discloses a device for testing the connection strength of a central drill pipe section, comprising: a testing frame; a testing platform mounted on the testing frame; two positioning parts mounted on the testing platform for positioning the workpiece to be tested; and a testing bracket mounted on the testing platform, on which multiple probes are slidably mounted. Through a self-locking transmission between a worm gear and a worm wheel, the workpiece to be tested can maintain a predetermined circumferential angle after rotating into position, thereby limiting the passive rotation of the workpiece during subsequent force application or probe contact. Thus, when the same workpiece is subjected to the next force test, the pressure component can still apply force to the same circumferential part, and there is a clearer positional correspondence between the first test data, the half-circumference follow-up test data, and the second test data, thereby improving the reliability of judging local indentation, overall bending, and asymmetric deformation states.

Description

Technical Field

[0001] This invention relates to the field of drilling tool testing equipment technology, and specifically to a device for testing the connection strength of a central drill pipe subsection. Background Technology

[0002] The center drill pipe sub is a component in drilling equipment used to transmit torque and bear axial loads. Its connection strength affects the stability of the drill string under impact, vibration, and alternating load conditions. Therefore, a strength test is usually required before the center drill pipe sub is put into use.

[0003] Existing testing methods mostly involve clamping and fixing the central drill pipe section, applying an impact load to its outer wall, and then observing whether loosening, deformation, or damage occurs. Alternatively, the local deformation can be obtained through a single-sided testing structure to determine whether the connection strength of the central drill pipe section meets the requirements.

[0004] However, since the central drill pipe section is a cylindrical component, the deformation state of the impacted side and the non-impacted side is not completely consistent after the impact load is applied. If only one side is tested, it is easily affected by local indentation, springback, or surface displacement, making it difficult to obtain the deformation response of both sides under the same impact condition, resulting in insufficient accuracy in judging the connection strength. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a device for testing the connection strength of a central drill pipe sub, aiming to alleviate the aforementioned problems to at least some extent.

[0006] The above-mentioned technical objective of the present invention is achieved through the following technical solution:

[0007] A device for testing the connection strength of a center drill pipe subsection includes:

[0008] Inspection rack;

[0009] The testing table is mounted on the testing frame;

[0010] Two positioning parts are provided on the testing platform for positioning the workpiece to be tested;

[0011] A detection bracket is provided on the detection table, and multiple probes are slidably mounted on the detection bracket. The multiple probes are arranged side by side along the axial direction of the workpiece to be detected. An elastic element is provided between the probes and the detection bracket. A displacement sensor is provided on the detection bracket for monitoring the displacement of the probes relative to the detection bracket.

[0012] A pressure component mounted on the inspection stand is used to apply a radial load to the workpiece to be inspected;

[0013] The detection component located between the detection table and the detection bracket is used to perform a first detection on the side of the workpiece away from the force-bearing position through multiple probes after the pressure component has applied force once.

[0014] The positioning part drives the workpiece to rotate around its own axis after the first detection is completed, so that the force-bearing side of the workpiece rotates to a position facing the probe.

[0015] The detection component is also used to perform a second detection on the stressed side of the workpiece using multiple probes, and to determine the deformation state of the workpiece connection based on the difference between the probe displacement data obtained from the first detection and the probe displacement data obtained from the second detection.

[0016] Preferably, the pressure component includes a force-applying frame disposed on the top of the testing platform, the force-applying frame being provided with a plurality of force-applying blocks, and a first hydraulic cylinder being provided on the testing frame, the telescopic shaft of the first hydraulic cylinder being connected to the force-applying frame.

[0017] Preferably, the detection bracket has multiple connection ports, the probe is slidably connected to the connection port, the elastic element is connected between the probe and the detection bracket, and multiple displacement sensors are disposed on the detection bracket, each displacement sensor extending into the corresponding connection port.

[0018] Preferably, the positioning part includes a mounting bracket connected to the testing table, the mounting bracket is provided with a second hydraulic cylinder, and a positioning shaft is rotatably connected to the piston rod of the second hydraulic cylinder.

[0019] Preferably, the detection component includes a lead screw rotatably connected to the detection stage, and the detection bracket is slidably connected to the detection stage and extends into the detection stage, engaging with the lead screw threadedly.

[0020] Preferably, a connecting plate is connected to the testing frame, a follower bracket is slidably connected to the connecting plate, a first spring is connected between the follower bracket and the connecting plate, the top of the follower bracket extends to the top of the force application frame, the bottom of the follower bracket extends into the testing table and is slidably connected to the testing table, a guide ring is connected to the follower bracket, a guide rod is connected to the inner wall of the guide ring, a guide sleeve is fixed to the outer wall of the lead screw, a spiral opening is opened on the outer wall of the guide sleeve, and the guide rod is inserted into the spiral opening.

[0021] Preferably, a first gear is connected to the outer wall of the positioning shaft, a connecting shaft is rotatably connected to the mounting bracket, a second gear meshing with the first gear is connected to the connecting shaft, a worm gear is connected to the connecting shaft, and a worm meshing with the worm gear is rotatably connected to the mounting bracket.

[0022] Preferably, a top plate is slidably connected to the mounting bracket, a rack is connected to the top of the top plate, a third gear meshing with the rack is connected to the worm gear, the bottom of the top plate extends into the interior of the testing table, and a third spring is connected between the top plate and the testing table. The top plate is located on the movement path of the follower bracket and has a predetermined distance between it and the bottom of the follower bracket. The outer wall of the guide sleeve has a straight section opening that communicates with the spiral opening.

[0023] In summary, the present invention has the following main beneficial effects:

[0024] This application utilizes the coordination of a force-applying frame, a follower bracket, a guide rod, a helical opening, and a lead screw to simultaneously move the detection bracket upwards as the pressure component completes one application of force and resets upwards. This achieves the effect of the probe elastically contacting the workpiece under test during a similar unloading phase. Thus, the first detection is not performed while the force-applying block is still holding the workpiece, nor after the workpiece has fully rebounded, but rather a defined detection starting point is established during the reset process of the pressure component. This allows the first detection data to more stably correspond to the initial deformation state after one radial load.

[0025] This application further improves upon this by providing a straight section opening on the guide sleeve that communicates with the spiral opening. This prevents the guide rod from rotating the guide sleeve and lead screw after entering the straight section opening, thus stopping the upward movement of the detection bracket and maintaining its detection position. Based on this, the follower bracket continues to move upward and pushes the top plate. The top plate, through a rack, third gear, and worm gear, drives the positioning shaft to rotate, ensuring that the rotation of the workpiece to be detected occurs after the probe preload has been determined. Therefore, the half-cycle follower detection data primarily originates from the circumferential contour of the workpiece's outer wall and the deformation changes after being subjected to force, without incorporating additional displacement caused by the continued feeding of the detection bracket.

[0026] Meanwhile, this application utilizes the self-locking transmission of the worm gear and worm wheel to ensure that the workpiece under test maintains a predetermined circumferential angle after rotating into position, thus limiting the passive rotation of the workpiece during subsequent force application or probe contact. In this way, when the same workpiece is subjected to the next force test, the pressure component can still apply force to the same circumferential location. The first test data, the half-circumferential follow-up test data, and the second test data have a clearer positional correspondence, thereby improving the reliability of judging local indentation, overall bending, and asymmetric deformation states. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0028] Figure 2 This is a schematic diagram of the pressure component structure of the present invention;

[0029] Figure 3This is a schematic diagram of the detection stage structure of the present invention;

[0030] Figure 4 This is a schematic diagram of the follower support structure of the present invention;

[0031] Figure 5 This is a schematic diagram of the detection bracket structure of the present invention;

[0032] Figure 6 This is a schematic diagram of the mounting bracket structure of the present invention;

[0033] Figure 7 yes Figure 6 Enlarged schematic diagram of the local structure at point A;

[0034] Figure 8 This is a schematic diagram of the guide sleeve structure of the present invention;

[0035] Figure 9 This is a cross-sectional schematic diagram of the mounting bracket structure of the present invention.

[0036] Figure label:

[0037] 100. Inspection stand; 101. Inspection table; 102. Inspection bracket; 103. Probe; 104. Elastic element; 105. Displacement sensor;

[0038] 200. Force-applying frame; 201. Force-applying block; 202. First hydraulic cylinder; 203. Connection port;

[0039] 300. Mounting bracket; 301. Second hydraulic cylinder; 302. Positioning shaft; 303. First gear; 304. Connecting shaft; 305. Second gear; 306. Worm gear; 307. Worm;

[0040] 400. Lead screw; 401. Connecting plate; 402. Follower bracket; 403. First spring; 404. Guide ring; 405. Guide rod; 406. Guide sleeve; 407. Helical opening;

[0041] 500, Top plate; 501, Rack; 502, Third gear; 503, Third spring; 504, Straight section opening. Detailed Implementation

[0042] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0043] refer to Figures 1-9This embodiment provides a device for testing the connection strength of center drill pipe sections, including a testing frame 100, a testing table 101, two positioning parts, a pressure component, a testing bracket 102, multiple probes 103, an elastic element 104, a displacement sensor 105, and testing components. The testing table 101 is mounted on the testing frame 100 and is used to support the workpiece to be tested and the supporting structure related to the testing process. The workpiece to be tested consists of two center drill pipe sections. The two positioning parts are spaced apart along the axial direction of the workpiece to be tested on the testing table 101. The two positioning parts are used to support and position the two ends of the workpiece to be tested, so that the workpiece to be tested can maintain a predetermined testing posture when subjected to radial loads.

[0044] At least one of the two positioning parts has a rotary drive structure that can drive the workpiece to be inspected to rotate around its own axis. After completing the first inspection, the workpiece to be inspected can rotate around its own axis, so that the force-bearing side, which was originally located on the side of the pressure component, rotates to a position facing the inspection bracket 102, providing a positional basis for the subsequent second inspection.

[0045] A pressure component is mounted on the inspection stand 100 and located on one side of the workpiece to be inspected. The pressure component applies a radial load to the workpiece. An inspection bracket 102 is mounted on the inspection table 101 and located on the side of the workpiece away from the pressure component. Multiple probes 103 are slidably mounted on the inspection bracket 102, arranged side-by-side along the axial direction of the workpiece. The arrangement of the probes 103 corresponds to the measured section of the workpiece, enabling the inspection component to acquire displacement data at multiple axial positions of the measured section, rather than detecting only a single position. Each probe 103 can slide relative to the inspection bracket 102. An elastic element 104 is provided between the probe 103 and the inspection bracket 102. The elastic element 104 provides elastic contact when the probe 103 contacts the workpiece and pushes the probe 103 back to its original position after it leaves the workpiece.

[0046] A displacement sensor 105 is also provided on the detection bracket 102. The displacement sensor 105 is used to monitor the displacement of the probe 103 relative to the detection bracket 102. During the specific detection, each probe 103 abuts against the outer wall of the workpiece under the action of the elastic element 104. Changes in the height of the corresponding position on the outer wall of the workpiece will cause different slippage of the corresponding probe 103. The displacement sensor 105 collects the displacement of each probe 103, forming a set of probe 103 displacement data distributed along the axial direction of the workpiece. This set of probe 103 displacement data can reflect the residual deformation distribution of the measured section of the workpiece on the corresponding side.

[0047] During testing, the two positioning units first position the workpiece to be tested, placing it between the pressure component and the testing bracket 102. At this time, the testing component positions the testing bracket 102 in a clearance position, and the multiple probes 103 do not contact the workpiece. Subsequently, the pressure component moves towards the workpiece and applies a radial load to it; after the force is applied, the pressure component resets and separates from the workpiece. Because the testing bracket 102 is in a clearance position during the force application phase, the probes 103 do not directly bear the impact or ballast applied by the pressure component, reducing the problems of probe jamming, bending, and displacement sensor 105 drift.

[0048] After the pressure component resets, the detection component drives the detection bracket 102 to move from the avoidance position to the detection position, causing multiple probes 103 to abut against the side of the workpiece away from the force-bearing position. Each probe 103 generates a corresponding displacement based on the deformation of the outer wall of that side of the workpiece. The displacement sensor 105 collects the displacement of each probe 103 to obtain the probe 103 displacement data obtained from the first detection. The probe 103 displacement data obtained from the first detection is used to characterize the deformation state of the side of the workpiece away from the force-bearing position after being subjected to radial load.

[0049] After the first test is completed, the positioning unit, while keeping the workpiece clamped in the same position, drives the workpiece to rotate around its own axis by a predetermined angle, preferably 180 degrees, so that the force-bearing side of the workpiece gradually rotates from a position away from the detection bracket 102 to a position facing the detection bracket 102. Since the position where the pressure component applies the radial load is set opposite to the detection direction of the detection bracket 102, after the workpiece rotates 180 degrees, the original force-bearing side can be transferred to the same detection direction of the detection bracket 102, thereby placing the side away from the force-bearing position corresponding to the first test and the force-bearing side corresponding to the second test under the detection reference of the same set of probes 103.

[0050] During the rotation of the workpiece under test, multiple probes 103 maintain elastic contact with the outer wall of the workpiece under the action of the elastic element 104. Each probe 103 slides relative to the detection bracket 102 as the circumferential contour of the outer wall of the workpiece changes. The displacement sensor 105 continuously collects the displacement changes of each probe 103 to form half-circumferential motion detection data of the workpiece from the side away from the force-bearing position to the force-bearing side. This half-circumferential motion detection data is used to reflect the deformation transition of the workpiece under test along the circumferential direction after being subjected to radial load, thereby distinguishing different states such as local indentation, overall bending, and asymmetric deformation.

[0051] After the workpiece to be tested rotates into position, the positioning part stops rotating and keeps the workpiece in a stable position, so that the force-bearing side of the workpiece faces the detection bracket 102. At this time, the detection component performs a second detection on the force-bearing side of the workpiece through multiple probes 103. The displacement sensor 105 again collects the displacement of each probe 103 relative to the detection bracket 102, and obtains the probe 103 displacement data obtained from the second detection. By comparing the probe 103 displacement data obtained from the first detection, the half-cycle follow-up detection data, and the probe 103 displacement data obtained from the second detection, the deformation state of the workpiece under radial load can be determined under the same clamping state and the same detection reference.

[0052] Since both the first and second inspections are performed by the same set of probes 103 on the same inspection bracket 102, and the workpiece rotates directly around its own axis between the two inspections, there is no need to disassemble or re-clamp the workpiece, nor is it necessary to change the inspection reference. Multiple probes 103, under the action of the elastic element 104, can adapt to the height changes of the outer wall of the workpiece during rotation, ensuring a good correspondence between the first and second inspection data. By comparing the difference between the probe 103 displacement data obtained from the first inspection and the probe 103 displacement data obtained from the second inspection, the difference in deformation on the front and back sides of the workpiece after radial load can be determined, and this difference can be used as the basis for inspecting the workpiece's connection strength.

[0053] Based on the above embodiments, the pressure component includes a force-applying frame 200, a first hydraulic cylinder 202, and multiple force-applying blocks 201. The force-applying frame 200 is located above the testing table 101, and the first hydraulic cylinder 202 is mounted on the testing frame 100. The telescopic end of the first hydraulic cylinder 202 is connected to the force-applying frame 200 and is used to drive the force-applying frame 200 to move up and down relative to the testing table 101.

[0054] Multiple force-applying blocks 201 are disposed on the side of the force-applying frame 200 facing the workpiece to be inspected, and are arranged at intervals along the axial direction of the workpiece. When the first hydraulic cylinder 202 drives the force-applying frame 200 to move downward, the multiple force-applying blocks 201 can act on different axial positions of the workpiece to be inspected, thereby forming a distributed radial load on the workpiece. The force-applying blocks 201 are detachably connected to the force-applying frame 200. Specifically, multiple mounting holes can be opened on the force-applying frame 200. During installation, the number and position of the force-applying blocks 201 can be selected according to the length, outer diameter, and force-bearing area to be inspected of the workpiece. When the workpiece to be inspected is short, the number of force-applying blocks 201 can be reduced to concentrate the force application range on the section to be inspected; when the workpiece to be inspected is long, the number of force-applying blocks 201 can be increased to cover a larger axial inspection range. With this configuration, the pressure component can be adapted to different specifications of center drill pipe sections without replacing the entire force-applying frame 200.

[0055] Based on the above embodiment, the detection bracket 102 has multiple connection ports 203, which are arranged side by side along the axial direction of the workpiece to be detected and correspond one-to-one with multiple probes 103. Each probe 103 is slidably connected to the corresponding connection port 203, allowing the probe 103 to move relative to the detection bracket 102 in a direction that approaches or moves away from the workpiece to be detected. The connection ports 203 guide the probes 103, preventing them from easily deflecting laterally when in contact with the outer wall of the workpiece to be detected, thereby ensuring that the displacement collected by the displacement sensor 105 corresponds to the radial change of the outer wall of the workpiece to be detected at that axial position.

[0056] The probe 103 includes a contact end for contacting the outer wall of the workpiece to be tested and a detection end located within the connection port 203. An elastic element 104 is connected between the probe 103 and the detection bracket 102. Specifically, the elastic element 104 can be sleeved on the outside of the probe 103. When the probe 103 contacts the outer wall of the workpiece to be tested and is pressed by the outer wall, the probe 103 slides along the connection port 203 into the detection bracket 102 and compresses the elastic element 104. When the pressing amount at the corresponding position on the outer wall of the workpiece to be tested decreases, the elastic element 104 pushes the probe 103 back to the direction of the workpiece to be tested. With this structure, the probe 103 can maintain elastic follow-up contact with the outer wall of the workpiece to be tested during the first detection, half-cycle follow-up detection, and second detection processes.

[0057] Multiple displacement sensors 105 are mounted on the detection bracket 102, with each displacement sensor 105 corresponding to a probe 103. The detection end of each displacement sensor 105 extends into the corresponding connection port 203 and is positioned opposite to the detection end, side wall detection surface, or limiting part of the corresponding probe 103. When the probe 103 slides within the connection port 203, the displacement sensor 105 collects the sliding displacement of the probe 103 relative to the detection bracket 102 and uses this sliding displacement as the displacement data of the probe 103 at that axial position. Since each probe 103 is located in a different connection port 203, each displacement sensor 105 can obtain the displacement changes at different axial positions of the workpiece to be detected, thereby forming multi-point detection data distributed along the axial direction of the workpiece to be detected.

[0058] During the testing process, after the pressure component applies a radial load to the workpiece to be tested, multiple probes 103 first perform a first test on the side of the workpiece to be tested away from the force-bearing position; then the positioning part drives the workpiece to be tested to rotate around its own axis, and the probes 103 slide within the connection port 203 in accordance with the outer contour of the workpiece under the action of the elastic element 104, and the displacement sensor 105 continuously collects the displacement changes of each probe 103; after the force-bearing side of the workpiece to be tested rotates to face the testing bracket 102, each displacement sensor 105 collects the displacement of the corresponding probe 103 again to obtain the probe 103 displacement data obtained in the second test.

[0059] Based on the above embodiments, the positioning part includes a mounting bracket 300, a second hydraulic cylinder 301, and a positioning shaft 302. The mounting bracket 300 is connected to the inspection table 101 and is located outside the end of the workpiece to be inspected. The second hydraulic cylinder 301 is mounted on the mounting bracket 300, with its piston rod facing the end of the workpiece to be inspected. The positioning shaft 302 is rotatably connected to the piston rod of the second hydraulic cylinder 301. When the second hydraulic cylinder 301 extends, the piston rod drives the positioning shaft 302 to move towards the end of the workpiece to be inspected, causing the positioning shaft 302 to abut against or insert into the end of the workpiece to be inspected, thereby axially positioning the workpiece to be inspected. When the second hydraulic cylinder 301 retracts, the piston rod drives the positioning shaft 302 away from the end of the workpiece to be inspected, facilitating the placement and removal of the workpiece.

[0060] The positioning shaft 302 is rotatably connected to the piston rod of the second hydraulic cylinder 301, allowing the positioning shaft 302 to rotate relative to the piston rod around its own axis. Therefore, after the positioning shaft 302 clamps and positions the end of the workpiece to be inspected, it does not restrict the workpiece's rotation around its own axis. When the workpiece needs to be rotated to the second inspection position after the first inspection, the positioning shaft 302 can rotate synchronously with the workpiece, preventing torsional friction or jamming between the positioning shaft 302 and the end of the workpiece.

[0061] Two positioning parts can be respectively set at both ends of the workpiece to be inspected. Before inspection, the two second hydraulic cylinders 301 drive the corresponding positioning shafts 302 to move towards the workpiece to be inspected, so that the two positioning shafts 302 clamp and position the two ends of the workpiece to be inspected, thereby keeping the workpiece to be inspected in a predetermined position between the pressure component and the inspection bracket 102. When the pressure component applies a radial load to the workpiece to be inspected, the two positioning shafts 302 can restrict the axial movement of the workpiece to be inspected, ensuring a stable correspondence between the force-bearing position and the detection position of the probe.

[0062] Based on the above embodiment, the detection component includes a lead screw 400. The lead screw 400 is rotatably connected to the detection table 101, and the detection bracket 102 is slidably connected to the detection table 101, with one end of the detection bracket 102 extending into the detection table 101 and threadedly engaging with the lead screw 400. The sliding direction of the detection bracket 102 relative to the detection table 101 is towards or away from the workpiece to be detected. When the lead screw 400 rotates, the detection bracket 102 moves along the detection table 101 under the action of the threaded engagement, thereby causing the multiple probes 103 on the detection bracket 102 to move towards or away from the workpiece to be detected as a whole.

[0063] Based on the above embodiment, a connecting plate 401 is connected to the inspection frame 100, which provides an installation base for the follower bracket 402. The follower bracket 402 is slidably connected to the connecting plate 401 and can move vertically relative to the connecting plate 401. A first spring 403 is connected between the follower bracket 402 and the connecting plate 401 to provide elastic reset for the follower bracket 402, so that the follower bracket 402 can maintain a predetermined initial position when it is not driven by the force-applying frame 200.

[0064] The top of the follower bracket 402 extends to the top of the force-applying frame 200, and the bottom of the follower bracket 402 extends downward into the detection table 101 and is slidably connected to the detection table 101. Through this arrangement, the upper part of the follower bracket 402 can form a follower engagement with the force-applying frame 200, and the lower part of the follower bracket 402 can transmit the follower action to the position of the lead screw 400 inside the detection table 101. The detection table 101 guides the bottom of the follower bracket 402, preventing the follower bracket 402 from swinging or deviating when moving with the force-applying frame 200.

[0065] A guide ring 404 is connected to the follower bracket 402. The guide ring 404 is sleeved around the guide sleeve 406 outside the lead screw 400, and a guide rod 405 is connected to the inner wall of the guide ring 404. The lead screw 400 is rotatably connected to the detection table 101, and the guide sleeve 406 is fixed to the outer wall of the lead screw 400, rotating synchronously with the lead screw 400. A helical opening 407 is provided on the outer wall of the guide sleeve 406, and the guide rod 405 is inserted into the helical opening 407. Since the guide rod 405 is driven to move up and down by the follower bracket 402, and the guide sleeve 406 is fixed to the outer wall of the lead screw 400, when the guide rod 405 moves relative to the lead screw 406 along the helical opening 407, the guide rod 405 will generate a circumferential thrust on the guide sleeve 406 through the helical opening 407, thereby driving the guide sleeve 406 and the lead screw 400 to rotate.

[0066] The detection bracket 102 is slidably connected to the detection table 101 and threadedly engaged with the lead screw 400. When the lead screw 400 rotates, the detection bracket 102 moves relative to the detection table 101 under the action of the threaded engagement. The rotation direction of the helical opening 407 and the thread rotation direction of the lead screw 400 are mutually coordinated, so that when the force application frame 200 completes one force application and returns to its upward position, the follower bracket 402 drives the guide rod 405 to move along the helical opening 407. The guide rod 405 drives the guide sleeve 406 and the lead screw 400 to rotate in a predetermined direction, thereby causing the detection bracket 102 to move upward toward the workpiece to be detected.

[0067] During the specific testing process, the first hydraulic cylinder 202 first drives the force-applying frame 200 to move downwards. The force-applying frame 200 then drives multiple force-applying blocks 201 to apply a radial load to the workpiece to be tested. During the force application process, the testing bracket 102 is in a relatively low position, and the multiple probes 103 will not prematurely and excessively press against the workpiece to be tested, thus avoiding the load during the force application stage being directly transmitted to the probes 103 and displacement sensor 105 through the workpiece to be tested. After the force application is completed, the first hydraulic cylinder 202 drives the force-applying frame 200 to reset upwards. During the upward movement, the force-applying frame 200 drives the follower bracket 402 to move synchronously. The guide rod 405 on the follower bracket 402 moves along the spiral opening 407 on the outer wall of the guide sleeve 406, and pushes the guide sleeve 406 to drive the lead screw 400 to rotate. After the lead screw 400 rotates, the detection bracket 102 moves upward toward the workpiece under the action of the threaded engagement, so that multiple probes 103 abut against the side of the workpiece away from the force position under the action of the elastic element 104. The displacement sensor 105 collects the displacement of each probe 103 and obtains the probe 103 displacement data obtained in the first detection.

[0068] The first spring 403 is used to ensure that the movement of the follower bracket 402 has a reset capability. When the force application bracket 200 returns to the predetermined position, the first spring 403 can assist the follower bracket 402 to maintain a stable position, so that the guide rod 405 is stably maintained at the corresponding position of the spiral opening 407, and the lead screw 400 is prevented from rotating uncontrollably.

[0069] With the above configuration, when the force-applying frame 200 moves upward, it drives the follower bracket 402 to move. The follower bracket 402 drives the guide sleeve 406 and the lead screw 400 to rotate through the cooperation of the guide rod 405 and the spiral opening 407. The lead screw 400 then drives the detection bracket 102 to move upward toward the workpiece to be inspected. Thus, a fixed correspondence is formed between the reset stroke of the force-applying frame 200, the rotation amount of the lead screw 400, and the upward movement amount of the detection bracket 102. This ensures that after each force application, multiple probes 103 can reach the workpiece to be inspected in similar unloading stages and similar initial compression states, thereby ensuring that the first detection data has good repeatability and providing a stable starting reference for subsequent half-cycle follower detection and second detection.

[0070] Based on the above embodiment, a first gear 303 is connected to the outer wall of the positioning shaft 302. A connecting shaft 304 is rotatably connected to the mounting bracket 300. A second gear 305 and a worm gear 306 are connected to the connecting shaft 304, with the second gear 305 meshing with the first gear 303. A worm 307 is also rotatably connected to the mounting bracket 300, meshing with the worm gear 306. With this configuration, when it is necessary to rotate the workpiece to be inspected around its own axis, the worm 307 is rotated, which drives the worm gear 306 to rotate. The worm gear 306 drives the connecting shaft 304 to rotate synchronously. The connecting shaft 304 then drives the first gear 303 to rotate via the second gear 305, and the first gear 303 drives the positioning shaft 302 to rotate, thereby causing the workpiece to be inspected, positioned by the positioning shaft 302, to rotate around its own axis.

[0071] After the first test is completed, the multiple probes 103 remain in elastic contact with the outer wall of the workpiece to be tested. At this time, the positioning shaft 302 is slowly rotated by rotating the worm gear 307, so that the workpiece to be tested gradually rotates from the side away from the force-bearing position towards the test bracket 102 to the side of the force-bearing position towards the test bracket 102. Since a self-locking transmission fit is formed between the worm gear 307 and the worm wheel 306, after the rotation of the worm gear 307 stops, the worm wheel 306 is not likely to drive the worm gear 307 to rotate in the opposite direction. The connecting shaft 304, the second gear 305, the first gear 303, and the positioning shaft 302 can remain in the current angular position, so that the workpiece to be tested is not likely to rotate back after rotating into position.

[0072] After the workpiece to be tested rotates to a predetermined angle, the self-locking action of the worm gear 307 and worm wheel 306 restricts the positioning shaft 302 from passively rotating under external force. Therefore, when the pressure component performs the next force test on the workpiece, even if the force block 201 applies a radial load to the workpiece, or multiple probes 103 maintain elastic contact with the outer wall of the workpiece, the workpiece can maintain its predetermined circumferential angle and is less prone to rotation due to force eccentricity, local undulations of the outer wall, or friction of the probes 103. In this way, the next force test can continue to correspond to the same circumferential part of the workpiece, avoiding discrepancies in the test data due to circumferential position shifts, thereby improving data consistency and judgment accuracy during repeated force tests.

[0073] Based on the above embodiment, the outer wall of the guide sleeve 406 is further provided with a straight section opening 504, which communicates with the spiral opening 407, and the extension direction of the straight section opening 504 is adapted to the sliding direction of the follower bracket 402. When the force applying frame 200 completes one force application and resets upward, the force applying frame 200 first drives the follower bracket 402 to move upward. The guide rod 405 on the follower bracket 402 moves along the spiral opening 407 on the outer wall of the guide sleeve 406, causing the guide sleeve 406 to drive the lead screw 400 to rotate. The lead screw 400 drives the detection bracket 102 to move upward toward the workpiece to be detected, and multiple probes 103 gradually form elastic contact with the outer wall of the workpiece to be detected. At this time, the bottom of the follower bracket 402 has not yet contacted the top plate 500, the positioning shaft 302 does not rotate, and the workpiece to be detected maintains its original circumferential position so as to complete the first detection on the side away from the force-bearing position first.

[0074] After the guide rod 405 enters the straight section opening 504 from the spiral opening 407, it no longer exerts a circumferential pushing effect on the guide sleeve 406 as it continues to move upward with the follower bracket 402. The angle between the guide sleeve 406 and the lead screw 400 is limited, and the detection bracket 102 stops moving upward and remains in the detection position. In this way, the multiple probes 103 have a stable initial elastic compression, and subsequent displacement changes mainly come from the outer wall contour of the workpiece to be detected and the deformation after being subjected to force, rather than from the additional displacement caused by the continued feeding of the detection bracket 102.

[0075] After the follower bracket 402 continues to move upward until it contacts the top plate 500, the follower bracket 402 pushes the top plate 500 upward relative to the mounting bracket 300. The rack 501 at the top of the top plate 500 drives the third gear 502 to rotate, and the third gear 502 drives the worm 307 to rotate. The worm 307 then drives the positioning shaft 302 to rotate through the worm wheel 306, connecting shaft 304, second gear 305 and first gear 303, thereby causing the workpiece to be tested to rotate around its own axis. Since the guide rod 405 is already located in the straight section opening 504 at this time, the detection bracket 102 no longer moves upward, and the probe 103 only extends and retracts with the circumferential contour change of the outer wall of the workpiece to be tested. The displacement sensor 105 can continuously collect half-cycle follower detection data of the workpiece to be tested during the process of rotating from the side away from the force position to the force position.

[0076] With the above configuration, the reset stroke of the force-applying frame 200 is divided into two consecutive stages. In the first stage, the guide rod 405 moves along the spiral opening 407 and drives the guide sleeve 406 and the lead screw 400 to rotate, causing the detection bracket 102 to move upward to the detection position. Multiple probes 103 first form a stable elastic contact with the workpiece to be detected. In the second stage, the guide rod 405 enters the straight section opening 504, the angle of the guide sleeve 406 and the lead screw 400 is limited, the detection bracket 102 stops moving upward, and the follower bracket 402 continues to move upward and pushes the top plate 500, which drives the positioning shaft 302 to rotate through the rack 501, the third gear 502 and the worm gear 307. Thus, the rotation of the workpiece to be detected occurs after the probe 103 has established a detection reference and the position of the detection bracket 102 is fixed, avoiding the mixing of the detection bracket 102 feed displacement into the workpiece rotation data. This allows the first detection data, the half-cycle follower detection data and the second detection data to be obtained continuously under the pre-compression state of the same probe 103, improving the accuracy of deformation judgment after being subjected to force.

[0077] Although embodiments of the 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 invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A device for testing the connection strength of a central drill pipe subsection, characterized in that, include: Inspection rack (100); A testing table (101) is provided on the testing frame (100). Two positioning parts are provided on the testing table (101) for positioning the workpiece to be tested; A detection bracket (102) is provided on the detection table (101). Multiple probes (103) are slidably arranged on the detection bracket (102). The multiple probes (103) are arranged side by side along the axial direction of the workpiece to be detected. An elastic element (104) is provided between the probes (103) and the detection bracket (102). A displacement sensor (105) is provided on the detection bracket (102) for monitoring the displacement of the probes (103) relative to the detection bracket (102). A pressure component mounted on the inspection fixture (100) is used to apply a radial load to the workpiece to be inspected; The detection component located between the detection table (101) and the detection bracket (102) is used to perform a first detection on the side of the workpiece away from the force-bearing position through multiple probes (103) after the pressure component completes one force application; The positioning part drives the workpiece to rotate around its own axis after the first detection is completed, so that the force-bearing side of the workpiece rotates to the position facing the probe (103). The detection component is also used to perform a second detection on the stressed side of the workpiece using multiple probes (103), and to determine the deformation state of the workpiece connection based on the difference between the probe (103) displacement data obtained from the first detection and the probe (103) displacement data obtained from the second detection.

2. The device for testing the connection strength of a central drill pipe subsection according to claim 1, characterized in that, The pressure component includes a force-applying frame (200) located on the top of the testing platform (101), the force-applying frame (200) having multiple force-applying blocks (201) on it, and a first hydraulic cylinder (202) on the testing frame (100), the telescopic shaft of the first hydraulic cylinder (202) being connected to the force-applying frame (200).

3. The device for testing the connection strength of a central drill pipe subsection according to claim 1, characterized in that, The detection bracket (102) has multiple connection ports (203), the probe (103) is slidably connected in the connection port (203), the elastic element (104) is connected between the probe (103) and the detection bracket (102), and multiple displacement sensors (105) are disposed on the detection bracket (102), each displacement sensor (105) extending into the corresponding connection port (203).

4. The central drill pipe short section connection strength testing device according to claim 2, characterized in that, The positioning part includes a mounting bracket (300) connected to the detection table (101), and a second oil cylinder (301) is provided on the mounting bracket (300). A positioning shaft (302) is rotatably connected to the piston rod of the second oil cylinder (301).

5. The central drill pipe short section connection strength testing device according to claim 4, characterized in that, The detection component includes a lead screw (400) rotatably connected to the detection stage (101), and a detection bracket (102) slidably connected to the detection stage (101) and extending into the detection stage (101) and threadedly engaged with the lead screw (400).

6. The central drill pipe short section connection strength testing device according to claim 5, characterized in that, A connecting plate (401) is connected to the testing frame (100). A follower bracket (402) is slidably connected to the connecting plate (401). A first spring (403) is connected between the follower bracket (402) and the connecting plate (401). The top of the follower bracket (402) extends to the top of the force application frame (200). The bottom of the follower bracket (402) extends into the testing table (101) and is slidably connected to the testing table (101). A guide ring (404) is connected to the follower bracket (402). A guide rod (405) is connected to the inner wall of the guide ring (404). A guide sleeve (406) is fixed to the outer wall of the lead screw (400). A spiral opening (407) is opened on the outer wall of the guide sleeve (406). The guide rod (405) is inserted into the spiral opening (407).

7. The central drill pipe short section connection strength testing device according to claim 6, characterized in that, The outer wall of the positioning shaft (302) is connected to a first gear (303), the mounting bracket (300) is rotatably connected to a connecting shaft (304), the connecting shaft (304) is connected to a second gear (305) that meshes with the first gear (303), the connecting shaft (304) is connected to a worm gear (306), and the mounting bracket (300) is rotatably connected to a worm (307) that meshes with the worm gear (306).

8. The central drill pipe short section connection strength testing device according to claim 7, characterized in that, A top plate (500) is slidably connected to the mounting bracket (300). A rack (501) is connected to the top of the top plate (500). A third gear (502) meshing with the rack (501) is connected to the worm gear (307). The bottom of the top plate (500) extends into the interior of the testing table (101) and is connected to the testing table (101) by a third spring (503). The top plate (500) is located on the movement path of the follower bracket (402) and has a predetermined distance between it and the bottom of the follower bracket (402). A straight section opening (504) is opened on the outer wall of the guide sleeve (406) and communicates with the spiral opening (407).

Images