Traction rod bidirectional loading test device and method

Abstract

The invention provides a traction rod bidirectional loading test device and method. The device comprises a vertical supporting frame, a loader, an adjusting plate, a sensor assembly and a guiding device. The guiding device comprises two vertical guiding columns, a lower connecting assembly and an upper connecting assembly. The two vertical guide columns are fixed to the bottom plate. The lower connecting assembly is configured to connect the first lifting lug of the vertical traction rod located between the two guide columns to the lower portions of the two guide columns. The upper portion of the upper connecting assembly is connected to the adjusting plate, the lower portion of the upper connecting assembly is connected to the second lifting lug, and the two guide columns slidably penetrate through the upper connecting assembly. The transverse displacement of the upper connecting assembly is rigidly restrained through the guide column, it is ensured that the load applied by the loader is transmitted along the axis of the traction pull rod, and precise stretching and compressing two-way loading is achieved.

Description

Technical Field

[0001] This disclosure relates to the field of rail vehicle technology, and in particular to a device and method for loading tests on traction rods of rail vehicles. Background Technology

[0002] The traction rod is a key load-bearing component in the running gear of a rail vehicle. Its two ends are connected to the car body and the bogie, respectively. Its core function is to efficiently and reliably transmit the traction and braking forces generated by the bogie to the car body, thereby driving the train or controlling its deceleration and stopping. As a core load-bearing component related to train operation safety, the mechanical properties of the traction rod are extremely important. Therefore, it is necessary to conduct systematic mechanical performance loading tests on it to verify whether its structural strength, fatigue life, and stiffness characteristics meet design and safety standards.

[0003] However, to buffer vibrations and impacts during operation, the ends of the traction rod are typically flexibly connected to metal lugs via rubber joints. Rubber materials undergo lateral expansion and deformation under pressure, preventing the nominal pressure applied by the testing device from being transmitted precisely along the theoretical axis of the traction rod. Some of the load is decomposed into useless lateral components. This makes it difficult to accurately control and measure the actual axial pressure borne by the traction rod, affecting the accuracy and reliability of the pressure loading test results. Summary of the Invention

[0004] To address at least one of the aforementioned and other technical problems in the related art, this disclosure provides a bidirectional loading test device for a traction rod. The traction rod includes a rod body and a first and a second lifting lug installed at both ends of the rod body. The test device includes: an upright support frame, a loader, an adjusting plate, a sensor assembly, and a guide device. The upright support frame includes a relatively fixed base plate and a top plate. The loader is connected below the top plate. The adjusting plate is horizontally positioned below the loader. The sensor assembly is connected at both ends to the loader and the adjusting plate, respectively, to measure the force applied by the loader to the adjusting plate. The guide device includes two upright guide posts, a lower connecting assembly, and an upper connecting assembly. The two upright guide posts are fixed to the base plate. The lower connecting assembly is configured to connect the first lifting lug of the upright traction rod, located between the two guide posts, to the lower part of the two guide posts. The upper part of the upper connecting assembly is connected to the adjusting plate, and the lower part is connected to the second lifting lug, and the two guide posts slidably pass through the upper connecting assembly and the adjusting plate.

[0005] According to an embodiment of this disclosure, the upper connecting assembly includes two transverse sleeves and two force-applying assemblies. Each transverse sleeve has a mounting hole adapted to receive one end of a first lifting lug. The two force-applying assemblies are connected between the two transverse sleeves and an adjusting plate, and each guide post slidably passes through the transverse sleeves and the force-applying assemblies.

[0006] According to embodiments of this disclosure, each force-applying component includes an upright sleeve and a fastening mechanism. The upright sleeve extends upward from the transverse sleeve through the adjusting plate, and has a radially outwardly projecting boss on its outer side that abuts against the lower surface of the adjusting plate. The fastening mechanism is releasably mounted on the end of the upright sleeve extending out of the adjusting plate, and the adjusting plate cooperates with the fastening mechanism or the boss to lift or press down the upright sleeve and the transverse sleeve.

[0007] According to an embodiment of this disclosure, the fastening mechanism includes a fastener with internal threads, the fastener being threadedly engaged with the end of the upright sleeve and abutting against the upper surface of the adjusting plate.

[0008] According to embodiments of this disclosure, a detachable fixing plate fixed above the base plate is also included, the fixing plate being connected to the lower end of the guide device.

[0009] According to an embodiment of this disclosure, a recess is provided on the base plate, and the test device further includes a stop member disposed in the recess. The stop member passes through the fixing plate and fixes the fixing plate to the base plate.

[0010] According to an embodiment of the present disclosure, the lower connecting assembly includes two lower sleeves respectively fitted onto the guide post, each lower sleeve being configured such that one end abuts against the fixed plate and the other end abuts against the lower surface of the second lifting lug.

[0011] According to an embodiment of this disclosure, the lower connecting assembly includes two upper sleeves respectively fitted onto the guide post, each upper sleeve being threadedly engaged with the guide post and abutting against the upper surface of the second lifting lug.

[0012] According to an embodiment of this disclosure, the sensor assembly includes a sensor, a first connecting part, and a second connecting part. One end of the sensor is detachably connected to the loader via the first connecting part, and the other end is detachably connected to the adjustment plate via the second connecting part.

[0013] According to embodiments of this disclosure, the loader is a hydraulic cylinder.

[0014] According to an embodiment of this disclosure, at least one strain gauge is attached to the tie rod body, the strain gauge being used to measure the deformation of the tie rod body during loading.

[0015] This disclosure also provides a bidirectional loading test method for a traction rod, characterized by using a test apparatus as described in any one of claims 1 to 11, the test method comprising the following steps: S1: installing the traction rod in the test apparatus and adjusting the position of the adjusting plate, the upper connecting assembly, and the traction rod to align them with the vertical guide column, thereby establishing an axial loading path along the vertical direction; S2: controlling the loader to apply tension and / or pressure to the traction rod along the axial direction of the guide column; S3: measuring and recording the applied load value through a sensor assembly during loading; S4: obtaining one or more performance parameters of the traction rod under load based on the load value and the corresponding test settings.

[0016] According to an embodiment of this disclosure, S4 is: obtaining the correspondence between the load value and the strain signal output by the strain gauge, so as to establish the load-strain curve of the traction rod or calculate the strain coefficient.

[0017] According to the illustrative embodiments of the present disclosure, a bidirectional loading test apparatus and method for a traction rod is provided. Two upright guide columns are fixed to a base plate, and a lower connecting assembly connects the first lug of the upright traction rod, located between the two guide columns, to the lower part of the two guide columns. The guide columns slidably pass through the upper connecting assembly connecting the adjusting plate and the traction rod, allowing the loader to apply a test load to the traction rod in the axial direction. During compression testing, the test apparatus can forcibly constrain the upper connecting assembly and the traction rod lug connected thereto to move axially along the upright guide columns, thereby overcoming the lateral deformation tendency of the rubber joint between the connecting ring and the lug of the traction rod. This limits the displacement of the traction rod relative to the loader in the non-loading direction (e.g., the lateral direction), ensuring that the load applied by the loader is applied to the traction rod in the axial direction (upright direction). This avoids measurement errors caused by skewed loading forces, enabling precise and reliable axial tensile and compression loading tests on the traction rod, and obtaining mechanical test data of the traction rod through a sensor assembly. Attached Figure Description

[0018] The above and other objects, features and advantages of this disclosure will become clearer from the following description of embodiments of this disclosure with reference to the accompanying drawings, in which:

[0019] Figure 1 This is a front view of the experimental apparatus in an embodiment of this disclosure;

[0020] Figure 2 This is a partial perspective view of the test apparatus in an embodiment of this disclosure;

[0021] Figure 3 This is another partial perspective view of the test apparatus in an embodiment of this disclosure;

[0022] Figure 4 This is another partial perspective view of the test apparatus in an embodiment of this disclosure;

[0023] Figure 5 This is a partially enlarged schematic diagram of the test apparatus in an embodiment of this disclosure;

[0024] The meanings of the reference numerals in the attached figure are as follows:

[0025] 1. Support frame; 11. Base plate; 12. Support column; 13. Top plate; 2. Loader; 3. Sensor assembly; 31. Sensor; 32. First connecting part; 33. Second connecting part; 4. Adjusting plate; 5. Upper connecting assembly; 51. Horizontal sleeve; 52. Vertical sleeve; 53. Fastening mechanism; 6. Guide device; 7. Traction rod; 71. Rod body; 72. First lifting lug; 73. Second lifting lug; 74. Rubber node; 8. Lower connecting assembly; 81. Upper sleeve; 82. Lower sleeve; 9. Fixing plate; 10. Stop. Detailed Implementation

[0026] To make the objectives, technical solutions and advantages of this disclosure clearer, the following detailed description is provided in conjunction with specific embodiments and the accompanying drawings.

[0027] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit this disclosure. The terms “comprising,” “including,” etc., as used herein indicate the presence of features, steps, operations, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, or components.

[0028] All terms used herein, including technical and scientific terms, have the meanings commonly understood by those skilled in the art, unless otherwise defined. It should be noted that the terms used herein are to be interpreted in a manner consistent with the context of this specification, and not in an idealized or overly rigid way.

[0029] When using expressions such as "at least one of A, B, and C," the meaning should generally be interpreted according to the understanding of someone skilled in the art. For example, "a system having at least one of A, B, and C" should include, but is not limited to, systems having A alone, having B alone, having C alone, having A and B, having A and C, having B and C, and / or having A, B, and C. Similarly, when using expressions such as "at least one of A, B, or C," the meaning should generally be interpreted according to the understanding of someone skilled in the art. For example, "a system having at least one of A, B, or C" should include, but is not limited to, systems having A alone, having B alone, having C alone, having A and B, having A and C, having B and C, and / or having A, B, and C.

[0030] In rail vehicles, the traction rod 7 is a key load-bearing component connecting the car body and the bogie, responsible for transmitting traction and braking forces. As trains develop towards high speed and heavy load, the dynamic loads (such as starting and braking impacts and alternating loads caused by track irregularities) borne by the traction rod 7 are becoming increasingly complex. Therefore, it is necessary to verify its structural strength, fatigue life, and reliability through mechanical performance tests.

[0031] Traditional testing methods often employ general-purpose material testing machines or simple fixtures, which are suitable for rigid structures. However, to buffer vibration, the traction rod 7 typically has a rubber joint 74 between the rod body and the lifting lug, forming a flexible connection. Under compression, the rubber joint expands laterally relative to the rod body, easily causing the lifting lug to displace perpendicular to the axial direction. During compression tests in relevant testing equipment, this lateral deformation lacks effective constraint, causing the applied load to deviate from the theoretical axis of the traction rod. The measured load value includes unnecessary lateral force components and cannot accurately reflect the actual axial pressure borne by the traction rod 7.

[0032] The aforementioned deviation in the load transfer path may cause discrepancies between the mechanical data (such as stiffness and load-deformation relationships) obtained under pressure conditions using traditional methods and the actual axial compressive behavior of the traction rod 7. This error will lead to unreliable real-time force monitoring results based on this type of traction rod 7.

[0033] Figure 1 This is a front view of the experimental apparatus in an embodiment of this disclosure.

[0034] According to some exemplary embodiments of this disclosure, a bidirectional loading test apparatus for a traction rod is provided, such as... Figure 1 As shown, the traction rod 7 includes a rod body and a first lug 72 and a second lug 73 installed at both ends of the rod body. The test apparatus includes: an upright support frame 1, a loader 2, an adjusting plate 4, a sensor assembly 3, and a guide device 6. The upright support frame 1 includes a relatively fixed base plate 11 and a top plate 13. The loader 2 is connected below the top plate 13. The adjusting plate 4 is horizontally positioned below the loader 2. The sensor assembly 3 is connected at both ends to the loader 2 and the adjusting plate 4 respectively to measure the force applied by the loader 2 to the adjusting plate 4. The guide device 6 includes two upright guide posts, a lower connecting assembly 8, and an upper connecting assembly 5. The two upright guide posts are fixed to the base plate 11. The lower connecting assembly 8 is configured to connect the first lug of the upright traction rod 7, located between the two guide posts, to the lower part of the two guide posts. The upper part of the upper connecting assembly 5 is connected to the adjusting plate 4, and the lower part is connected to the second lug, and the two guide posts slide through the upper connecting assembly 5 and the adjusting plate.

[0035] In this implementation, the bidirectional loading test device for the traction rod is a vertical structure. Two upright guide columns are fixed to the base plate 11, and the upper connecting assembly 5 of the connecting adjustment plate 4 and the traction rod 7 slidably passes through these guide columns, guiding the loading force to the axial direction of the traction rod. During the compression test, the guide columns constrain the upper connecting assembly 5 and the connecting lug of the traction rod 7 to move axially along the guide columns, thereby overcoming the lateral deformation tendency of the rubber node 74. This allows the load applied by the loader 2 to be converted into axial pressure along the axis of the traction rod 7, avoiding measurement errors caused by skewed loading force. Combined with the lower connecting assembly 8 fixing the other end of the traction rod 7 and the sensor assembly 3 directly measuring the load, precise and reliable axial tensile and axial compressive loading of the traction rod 7 is ultimately achieved. On the other hand, since both the guide column and the traction rod are set upright, the possibility of the load applied by the loader 2 in the upright direction due to the weight of the guide column and the traction rod itself being deviated from the axial direction of the traction rod (the extension direction of the geometric axis of the traction rod) is avoided, thereby keeping the direction of the load application consistent with the axial direction of the traction rod.

[0036] Figure 2 This is a partial perspective view of the test apparatus in an embodiment of this disclosure.

[0037] In some illustrative embodiments of this disclosure, such as Figure 2 As shown, the tie rod body 71 is a slender, high-strength metal rod or tube, serving as the main axial load-bearing frame. Mechanical interfaces, such as connecting rings, are provided at both ends for connection. The first lug 72 and the second lug 73 are fitted within the two connecting rings, and a rubber node 74 is provided between the connecting ring and the first lug 72 or the second lug 73. The tie rod body 71, the first lug 72, and the second lug 73 are typically metal castings or forgings, with connecting portions featuring pin holes on their outer sides for hinged connection to the vehicle body or bogie frame during actual vehicle installation. The rubber node 74 is a flexible connector made of an elastomeric material (such as rubber) through a vulcanization process, achieving an elastic connection between the metal rod body and the metal lug.

[0038] In some illustrative embodiments of this disclosure, such as Figure 1 As shown, the support frame 1 can adopt a welded frame structure. Specifically, the base plate 11 and the top plate 13 are steel plates with sufficient thickness and flatness, and the two are connected by multiple vertically arranged support columns 12. The two ends of the support columns 12 can be welded and fixed to the base plate 11 and the top plate 13 respectively, thus forming a rigid whole. Threaded holes, T-slots, or other standard interfaces can be provided on the base plate 11 for installing or fixing other components. The top plate 13 provides an interface for installing the loader 2, which can also be achieved by welding a base, bolting, or other methods.

[0039] In some other illustrative embodiments of this disclosure, the two ends of the support column 12 are detachably connected to the base plate 11 and the top plate 13 respectively via flanges and high-strength bolts to facilitate transportation and assembly. Alternatively, the support frame 1 can be constructed from large profiles connected by welding or bolting to form a three-dimensional truss structure, with its top and bottom forming the functional surfaces of the top plate 13 and the base plate 11 respectively. The materials of the base plate 11, the top plate 13, and the support column 12 are not limited to steel; other hard panels such as stone slabs can also be used, as long as a reliable installation foundation can be provided.

[0040] In this implementation, the rigid connection of the base plate 11, top plate 13, and support columns 12 forms an upright support frame 1, providing a stable foundation platform with a defined geometric reference for the entire test apparatus. The base plate 11 provides a horizontal mounting reference surface for the entire apparatus, ensuring that the initial positioning of the guide device 6 and the lower end of the traction rod 7 is perpendicular to the ground. The top plate 13 provides a robust reaction support point for the loader 2, capable of withstanding the tensile and compressive forces generated during loading without significant deformation or displacement. Multiple support columns 12 transfer the load between the base plate 11 and the top plate 13 and maintain the parallelism and distance stability between them, thereby ensuring the spatial geometric accuracy and rigidity of the force transmission path from the loader 2 to the traction rod 7.

[0041] Figure 3 This is another partial perspective view of the test apparatus in an embodiment of this disclosure, where the partial view is a perspective view.

[0042] According to embodiments of this disclosure, such as Figure 3 As shown, the upper connecting assembly 5 includes two transverse sleeves 51 and two force-applying assemblies. Each transverse sleeve 51 has a mounting hole adapted to receive one end of the first lifting lug 72. The two force-applying assemblies are connected between the two transverse sleeves 51 and the adjusting plate 4, and each guide post slidably passes through the transverse sleeve 51 and the force-applying assembly.

[0043] In some illustrative embodiments of this disclosure, the upper connecting assembly 5 may include two transverse sleeves 51 and two force-applying components. Each transverse sleeve 51 is a horizontally placed cylindrical member with an internal mounting hole, which is a through hole extending horizontally through the transverse sleeve 51. The shape and size of the mounting hole are configured to accommodate the end of the first lifting lug 72. Specifically, the contour of the mounting hole matches the outer surface of the end of the first lifting lug 72 to achieve relative fixation between the lifting lug and the sleeve in the circumferential direction (i.e., the direction of rotation about the vertical axis). A small clearance fit or transition fit may be used between the mounting hole and the end of the lifting lug to ensure smooth assembly and no significant shaking during operation. To further facilitate assembly, the entrance edge of the mounting hole may be chamfered or rounded.

[0044] Furthermore, a wear-resistant bushing may be embedded in the mounting hole, or a radial locking screw may be provided for further locking and fixing after the lug is inserted.

[0045] In this implementation, by employing a hole profile that matches the non-circular cross-section of the lug end, reliable positioning of both in all directions within the horizontal plane is achieved, particularly avoiding rotation of the lug relative to the sleeve. This ensures that the lug, the transverse sleeve 51, and the connected force-applying components constitute a rigid assembly with no relative movement in the horizontal direction.

[0046] According to embodiments of this disclosure, such as Figure 3 As shown, each force-applying component includes an upright sleeve 52 and a fastening mechanism 53. The upright sleeve 52 extends upward from the transverse sleeve 51 through the adjusting plate 4, and the outer side of the upright sleeve 52 has a radially outwardly protruding boss that abuts against the lower surface of the adjusting plate 4. The fastening mechanism 53 is releasably mounted on the end of the upright sleeve 52 that extends out of the adjusting plate 4, and the adjusting plate 4, through cooperation with the fastening mechanism 53 or the boss, raises or lowers the upright sleeve 52 and the transverse sleeve 51.

[0047] In some illustrative embodiments of this disclosure, such as Figure 3 As shown, the upright sleeve 52 is a vertically arranged tubular or rod-shaped component, whose lower end extends upward from the top of the transverse sleeve 51 by welding, threaded connection, or integral molding with the transverse sleeve 51. The upright sleeve 52 passes upward through a pre-drilled through hole in the adjusting plate 4. On the outer wall of the upright sleeve 52, there is a radially outward protruding annular boss. When the upright sleeve 52 passes through the adjusting plate 4, the lower surface of the boss abuts against the lower surface of the adjusting plate 4, thereby bearing the downward pressure from the adjusting plate 4. The fastening mechanism 53 is a releasable locking component installed on the part of the upright sleeve 52 that extends out of the adjusting plate 4. The part of the upright sleeve 52 that extends out of the adjusting plate 4 is machined with external threads. By tightening the nut so that its lower end face abuts against the upper surface of the adjusting plate 4, it can clamp the adjusting plate 4 together with the lower boss, thereby reliably and detachably fixing the upright sleeve 52, the transverse sleeve 51, and the traction rod 7 lug connected thereto to the adjusting plate 4.

[0048] In this implementation, the boss defines the relative position reference between the force-applying component and the adjusting plate 4 in the vertical direction and directly bears the downward pressure of the adjusting plate 4 during the test. The fastening mechanism 53 provides an adjustable clamping force, and through its cooperation with the upper and lower parts of the boss, it firmly clamps the adjusting plate 4 in the middle, thereby achieving a rigid connection between the adjusting plate 4 and the force-applying component without relative displacement. This allows the lifting force or downward pressure applied by the loader 2 through the adjusting plate 4 to be converted into a pulling or pushing force on the vertical sleeve 52 and the entire horizontal sleeve 51 assembly through the transmission of the fastening mechanism 53 or the support of the boss, ultimately transferring the load to the lifting lug of the traction rod 7.

[0049] According to an embodiment of this disclosure, the fastening mechanism 53 includes a fastener with internal threads, which is threadedly engaged with the end of the upright sleeve 52 and abuts against the upper surface of the adjusting plate 4.

[0050] In some illustrative embodiments of this disclosure, the fastening mechanism 53 employs a fastener with internal threads, typically a standard nut or a specially designed lock nut. The end of the upright sleeve 52 extending upwards from the adjusting plate 4 is machined with external threads that match the internal threads of the fastener. During installation, the fastener is screwed onto this externally threaded section and tightened using a tool until the lower end face of the fastener (or via a washer) firmly abuts against the upper surface of the adjusting plate 4. This creates a clamping condition between the fastener, the adjusting plate 4, and the boss on the upright sleeve 52.

[0051] In this implementation, the threaded fit allows for easy adjustment of the clamping force and complete release when needed, enabling quick assembly and disassembly of the force-applying component and the adjusting plate 4, as well as height adjustment, thereby improving the applicability and ease of maintenance of the device.

[0052] In some illustrative embodiments of this disclosure, a fixing plate 9 is also included, which is fixed to the base plate.

[0053] Figure 4 This is another partial perspective view of the test apparatus in an embodiment of this disclosure.

[0054] According to embodiments of this disclosure, such as Figure 4 As shown, the lower connecting assembly 8 includes two lower sleeves 82 respectively fitted onto the guide post. Each lower sleeve 82 is configured such that one end abuts against the fixed plate 9 and the other end abuts against the lower surface of the second lifting lug 73.

[0055] In some illustrative embodiments of this disclosure, the lower sleeve 82 is constructed as a hollow columnar member with an inner diameter slightly larger than the outer diameter of the guide post, thereby allowing it to be loosely fitted onto the corresponding guide post. The lower end of the lower sleeve 82 is machined with a flat end face, which directly abuts against or indirectly abuts against the upper surface of the fixing plate 9 via a gasket. The upper end of the lower sleeve 82 is also machined with a flat end face, which is configured to abut against the lower surface of the second lifting lug 73 of the traction rod 7.

[0056] In this implementation, a lower sleeve 82, with its lower end abutting against the fixed plate 9 and its upper end abutting against the lower surface of the second lifting lug 73, provides a precise and stable axial mounting reference point for the traction rod 7. During testing, this structure can reliably withstand the downward gravity and potential load components from the second lifting lug 73, and transmits the force to the base plate 11 through the fixed plate 9, thereby constraining the vertical displacement of this end. Simultaneously, since the lower sleeve 82 is fitted onto the guide post, it also withstands significant pressure during pressure loading tests, thus possessing a certain lateral load capacity and providing auxiliary lateral restraint.

[0057] According to an embodiment of the present disclosure, the lower connecting assembly 8 includes two upper sleeves 81 respectively sleeved on the guide post, each upper sleeve 81 being threadedly engaged with the guide post and abutting against the upper surface of the second lifting lug 73.

[0058] In some illustrative embodiments of this disclosure, the upper sleeve 81 is constructed as a hollow cylindrical member with internal threads machined on its inner wall, capable of engaging with the external threads machined on the corresponding section of the guide post. By rotating the upper sleeve 81, it can move vertically up and down along the threaded section of the guide post. The lower end of the upper sleeve 81 is machined with a flat annular end face, which abuts against the upper surface of the second lifting lug 73 of the traction rod 7 when screwed to a predetermined position. By tightening, this end face can apply a downward axial clamping force to the second lifting lug 73.

[0059] In this implementation, the second lifting lug 73 is securely clamped and fixed in a preset vertical position from both above and below by working in conjunction with the lower sleeve 82. The threaded fit provides continuous and precise height adjustment capability to accommodate different specifications of traction rods 7 or test requirements.

[0060] According to an embodiment of this disclosure, the loader 2 is a hydraulic cylinder.

[0061] In some illustrative embodiments of this disclosure, the cylinder body of the hydraulic cylinder is installed below the top plate 13 of the support frame 1 by means of bolt connection or flange fixation, and its piston rod extends vertically downward as the output end. The hydraulic power unit is connected to the hydraulic cylinder through oil pipes to provide it with controllable hydraulic oil, thereby driving the piston rod to output precise and controllable thrust or pull force.

[0062] In this implementation, a hydraulic cylinder is used as the loader 2, which can provide the required large, precisely controllable unidirectional or alternating load for the test. The force output by the loader 2 is transmitted to the traction rod 7 through the sensor assembly 3 and the adjustment plate 4, providing the loading power for the entire test.

[0063] In other illustrative embodiments of this disclosure, the loader 2 may also employ other mechanisms capable of providing linear output and controllable load. For example, an electric servo actuator, a pneumatic cylinder, or a mechanical screw loading mechanism. The key is to ensure that these mechanisms are fixedly connected to the top plate 13 and that their output axes are aligned with the vertical direction of the support frame 1.

[0064] In some illustrative embodiments of this disclosure, the adjustment plate 4 is a horizontally arranged rigid plate. A connection interface is provided in the middle of the plate for detachable connection to the lower end of the sensor assembly 3, for example, via a threaded hole. Through holes are formed on the plate at positions corresponding to the two guide posts, allowing relevant components of the upper connecting assembly 5 to pass upwards through these through holes. The adjustment plate 4 is made of metal, such as steel plate, and its thickness is determined according to the required stiffness and load magnitude to ensure minimal deformation under test load. It is understood that the greater the stiffness and thickness of the material used for the adjustment plate 4, the smaller the deformation under test load, provided that the deformation of the adjustment plate 4 is within the allowable error range.

[0065] In this implementation, the upper part of the adjusting plate 4 receives the load from the loader 2 via the sensor assembly 3, and the lower part transmits the load to the traction rod 7 via the upper connecting assembly 5. The adjusting plate 4 transmits the load measured by the sensor assembly 3 downwards. At the same time, the through hole on the adjusting plate 4 cooperates with the guide post and the upper connecting assembly 5, which not only restricts the lateral displacement of the latter, but also provides a constraint surface for its vertical sliding, thereby ensuring that during the loading process, the force transmission path from the adjusting plate 4, the upper connecting assembly 5 to the traction rod 7 is always consistent with the vertical axis defined by the guide post.

[0066] Furthermore, when the guide post only passes through the lower connecting assembly 8 and the upper connecting assembly 5, the guide post guides the load force on the traction rod 7. When the guide post passes through the adjusting plate 4, the horizontal movement of the adjusting plate 4 is also restricted by the guide post, and the guide post also guides the load force applied to the adjusting plate 4, further improving the guiding effect.

[0067] According to embodiments of this disclosure, such as Figure 2 As shown, the sensor assembly 3 includes a sensor 31, a first connecting part 32 and a second connecting part 33. One end of the sensor 31 is detachably connected to the loader 2 through the first connecting part 32, and the other end is detachably connected to the adjustment plate 4 through the second connecting part 33.

[0068] In some illustrative embodiments of this disclosure, the sensor 31 is selected as a resistance strain gauge force sensor or a piezoelectric force sensor. Resistance strain gauge force sensors offer high measurement accuracy, good linearity, excellent long-term stability, and strong anti-interference capabilities, making them suitable for scenarios requiring high-precision quasi-static or low-to-medium frequency dynamic load measurements. Piezoelectric force sensors have high stiffness and good dynamic response characteristics, making them suitable for capturing impact loads or high-frequency dynamic loads. Alternatively, other force sensors based on principles such as capacitive or magnetostrictive sensors can be selected depending on the actual working conditions to meet specific measurement range, environmental adaptability, or installation size requirements.

[0069] In some illustrative embodiments of this disclosure, the first connecting part 32 and the second connecting part 33 are respectively connecting joints with internal or external threads, or transition plates with flanges. By threading or bolting, the first connecting part 32 achieves a detachable rigid connection between the upper end of the sensor 31 and the output end of the loader 2 (such as the piston rod joint of a hydraulic cylinder); similarly, the second connecting part 33 achieves a detachable rigid connection between the lower end of the sensor 31 and the connecting interface in the middle of the adjusting plate 4.

[0070] In some illustrative embodiments of this disclosure, the first connecting portion 32 and / or the second connecting portion 33 may be integrated into the interface form of the sensor 31 body. Alternatively, to achieve quick assembly and disassembly, the connecting portion may adopt a quick-clamp structure with a locking pin.

[0071] In this embodiment, by detachably connecting the sensor 31 between the loader 2 and the adjusting plate 4 via the first connecting part 32 and the second connecting part 33, the detachable connection facilitates individual testing, maintenance, or replacement of the sensor 31. During maintenance or replacement, it is not necessary to disassemble the entire loading frame, thus improving the usability and ease of maintenance of the device.

[0072] In some other illustrative embodiments of this disclosure, the second connecting part 33 is configured to have a columnar body, one end of which is provided with an integrally formed or fixedly connected radial boss. During installation, the lower surface of the boss abuts against the upper surface of the adjusting plate 4. The other end of the columnar body passes sequentially through the corresponding through hole on the adjusting plate 4 and the connection interface at the lower end of the sensor 31, and is locked below the sensor 31 by fasteners such as nuts, thereby achieving reliable fixation of the sensor 31, the second connecting part 33, and the adjusting plate 4.

[0073] In this implementation, the boss on the second connecting part 33 forms a positioning reference. By abutting against the surface of the adjusting plate 4, the vertical installation position of the second connecting part 33 and the connected sensor 31 can be quickly and accurately determined, which helps ensure the alignment of the sensor 31's axis. This structure, combined with a threaded fastening method, achieves a stable connection while also ensuring ease of assembly and disassembly.

[0074] In some illustrative embodiments of this disclosure, two upright guide posts can be directly fixed to the base plate 11. Specifically, the lower end of the guide post can be locked to the base plate 11 by means of a flange and high-strength bolts, or it can be directly inserted into a pre-set base in the base plate 11 and fixed by circumferential screws.

[0075] Figure 5 This is a partially enlarged schematic diagram of the test apparatus in an embodiment of this disclosure.

[0076] According to embodiments of this disclosure, such as Figure 5 As shown, it also includes a detachable fixing plate 9 fixed above the base plate 11, and the fixing plate 9 is connected to the lower end of the guide device 6.

[0077] In some other illustrative embodiments of this disclosure, the guide post is indirectly fixed to the base plate 11 by a fixing plate 9. The fixing plate 9 is detachably placed flat above the base plate 11, and it can be fixed to the base plate 11 by locating pins and bolts. The lower end of the guide post can be rigidly connected to the fixing plate 9 by welding, interference fit or threaded connection, or the fixing plate 9 and the guide post can be integrally formed by casting or forging.

[0078] In this implementation, by rigidly fixing the guide columns directly or via the fixing plate 9 to the base plate 11, a stable and precisely positioned installation foundation is established for the entire guiding device 6. The direct fixing method is simple in structure, has a short force transmission path, and good overall rigidity. The indirect fixing method using the detachable fixing plate 9 allows the guide column assembly to be disassembled, maintained, or replaced as a single module, improving the modularity and maintenance convenience of the device. The detachable design of the fixing plate 9 itself also facilitates the overall adjustment of the guide column spacing or the replacement of guide components of corresponding specifications when testing traction rods 7 of different sizes or specifications.

[0079] In some illustrative embodiments of this disclosure, a recess is machined or cast onto the upper surface of the base plate 11. This recess can be a circular countersunk hole, a rectangular groove, or other regular shape. The stop 10 is a threaded fastener such as a bolt or screw that matches the shape of the recess. During installation, the head of the stop 10 is first fixed in the recess, and the tail extends upward through the fixing plate 9. A nut is provided at the tail to fasten the stop 10 to the fixing plate 9.

[0080] According to embodiments of this disclosure, the stop 10 itself can be a threaded fastener. After being screwed into the threaded hole at the bottom of the recess of the base plate 11, its protruding head portion engages with the through hole of the fixing plate 9 to achieve locking. Alternatively, the recess and the stop 10 can be fitted with a tapered surface to achieve self-centering and tightening.

[0081] In this implementation, the stop 10, which is located within the recess of the base plate 11 and passes through the fixing plate 9, provides constraint on the fixing plate 9 beyond the bolt tightening force. This effectively prevents the fixing plate 9 from laterally sliding or rotating relative to the base plate 11 when subjected to complex loads (especially horizontal components or torques) from the guide column. Furthermore, it avoids guide axis misalignment caused by loose foundation connections.

[0082] In some other illustrative embodiments of this disclosure, multiple stops 10 may be provided. The multiple stops 10 may be circumferentially distributed or symmetrically arranged in corresponding recesses of the base plate 11, and each passing through a corresponding through hole on the fixing plate 9. All the stops 10 work together to constrain and lock the fixing plate 9 to the base plate 11.

[0083] In this implementation, by setting multiple stoppers 10, a more balanced and reinforced multi-point constraint can be formed on the fixed plate 9. This arrangement can effectively disperse and resist loads and moments from different directions, enhance the torsional and anti-slip capabilities of the fixed plate 9 under complex stress conditions, and thus further improve the rigidity and stability of the entire guide device 6 mounting base.

[0084] According to an embodiment of the present disclosure, at least one strain gauge is attached to the tie rod body 71, the strain gauge being used to measure the deformation of the tie rod body 71 during loading.

[0085] In some illustrative embodiments of this disclosure, at least one strain gauge may be attached to a specific location on the tie rod body 71. Specifically, the strain gauge is a resistance strain gauge, which is firmly attached to the tie rod body 71 using a special adhesive. This area is typically selected in a section of the body with a clear or uniform stress distribution to sensitively reflect the axial strain of the rod. The grid wires of the strain gauge are parallel to the theoretical axis of the tie rod body 71. The leads of the strain gauge are connected to an external signal conditioner and data acquisition system.

[0086] In other illustrative embodiments of this disclosure, strain rosettes composed of multiple strain gauges or mutually compensating measurement bridges can be used to obtain more comprehensive strain field information or to compensate for temperature effects. For tie rods with special surface conditions, welded strain gauges can be used.

[0087] In this implementation, the strain gauge directly and in real-time converts the microscopic mechanical deformation (strain) of the rod caused by force during loading into a measurable electrical signal (typically a change in resistance). By measuring this strain signal and combining it with the external load value applied to the traction rod 7, which is synchronously and accurately measured by the sensor assembly 3, a "load-strain" correspondence can be established for the specific traction rod 7 under axial stress. This yields the strain curve or strain coefficient of the traction rod 7. Furthermore, in subsequent actual vehicle operation, this strain signal, combined with the load value measured by the sensor assembly, can establish the load-strain relationship of the traction rod, providing a data foundation for traction rod condition monitoring, safety assessment, and predictive maintenance.

[0088] This disclosure also provides a bidirectional loading test method for a traction rod 7, using the above-mentioned test apparatus, and the test method includes the following steps:

[0089] S1: Install the traction rod 7 in the test device, and adjust the position of the adjusting plate 4, the upper connecting component 5 and the traction rod 7 so that they are aligned with the vertical guide column to establish an axial loading path along the vertical direction;

[0090] S2: Control the loader 2 to apply tension and / or pressure to the traction rod 7 along the axial direction of the guide column;

[0091] S3: During the loading process, the applied load value is measured and recorded by sensor component 3;

[0092] S4: Based on the load value and the corresponding test settings, obtain one or more performance parameters of the traction rod 7 under load.

[0093] In some illustrative embodiments of this disclosure, in step S1, the operator first places the traction rod 7 inside the test device, with its first lug 72 housed in the transverse sleeve 51 of the upper connecting assembly 5, and its second lug 73 supported on the lower sleeve 82 of the lower connecting assembly 8. Subsequently, tools (such as a level, dial indicator, or optical alignment instrument) are used to detect and fine-tune the spatial orientation of the adjusting plate 4, the upper connecting assembly 5, and the traction rod 7 as a whole, ensuring that the axis of the traction rod 7 is parallel and coplanar with the axes of the two vertical guide columns. This establishes a theoretically lateral-free vertical force transmission path between the loader 2, sensor 31, adjusting plate 4, and traction rod 7.

[0094] In step S2, the loader 2 (such as a hydraulic cylinder) is driven by the control system to extend or retract its piston rod along the axial direction of the guide column, thereby applying a preset axial tensile or compressive force to the aligned traction rod 7; the test can be monotonic loading, cyclic loading, or loading according to a specific load spectrum.

[0095] In step S3, while the loader 2 is working, the sensor assembly 3 connected in series with the loader 2 and the adjustment plate 4 converts the sensed force signal into an electrical signal in real time, and the data acquisition system synchronously records the changes of these load values ​​with time or displacement.

[0096] In step S4, the load data recorded in step S3, combined with the type of test setting (such as calibration test, stiffness test, fatigue test), is calculated and analyzed by the data processing unit, and finally outputs one or more performance parameters of the traction rod 7, such as load-displacement curve, axial stiffness value, or load-strain calibration coefficient calculated by synchronously acquired strain signal.

[0097] In this implementation, the initial positional deviation between the various components of the device and the traction rod 7 is actively eliminated through the key step S1, ensuring that subsequent loading can proceed along the preset vertical axis. Step S2 implements bidirectional loading on the established precise path, so that the lateral expansion tendency of the traction rod 7 (especially its rubber node 74) under pressure is suppressed by the rigid constraint formed by the guide post and the connecting assembly, thereby realizing a realistic simulation of axial pressure conditions. Sensor 31 measures high-fidelity load data under a controlled and directional loading environment, and the performance parameters obtained based on this data have high accuracy and reliability.

[0098] According to an embodiment of this disclosure, S4 is: to obtain the correspondence between the load value and the strain signal output by the strain gauge, so as to establish the load-strain curve of the traction rod 7 or calculate the strain coefficient.

[0099] In some illustrative embodiments of this disclosure, step S4 involves the data acquisition system synchronously recording the load value measured in real time by the sensor component 3 and the strain electrical signal output in real time by the strain gauge attached to the tie rod body 71 during the loading process. A unified timestamp or trigger signal ensures the correspondence between the load and strain data. Subsequently, the acquired paired data are processed and analyzed, for example, by plotting a scatter plot of the load value and strain signal value, and establishing a mathematical relationship model between the two through a fitting method. Finally, a load-strain curve is generated based on this model to visually characterize the relationship between the two, or a specific strain coefficient is directly calculated.

[0100] In other illustrative embodiments of this disclosure, the specific data processing method for this step can be adjusted according to requirements. For example, the data for tensile and compressive conditions can be processed independently to establish two curves or two coefficients; or, in cyclic loading tests, the hysteresis loop can be analyzed to evaluate energy loss characteristics; or linearity, repeatability, and other indicators can be determined through statistical analysis.

[0101] It should also be noted that the directional terms mentioned in the embodiments, such as "up," "down," "front," "back," "left," and "right," are only for reference to the directions in the accompanying drawings and are not intended to limit the scope of protection of this disclosure. Throughout the drawings, the same elements are identified by the same or similar reference numerals. Conventional structures or constructions will be omitted where they may cause confusion in understanding this disclosure.

[0102] The embodiments of this disclosure have been described above. However, these embodiments are for illustrative purposes only and are not intended to limit the scope of this disclosure. Although various embodiments have been described above, this does not mean that the measures in the various embodiments cannot be used advantageously in combination. The scope of this disclosure is defined by the appended claims and their equivalents. Various substitutions and modifications can be made by those skilled in the art without departing from the scope of this disclosure, and all such substitutions and modifications should fall within the scope of this disclosure.

Claims

1. A bidirectional loading test device for a traction rod, characterized in that, The traction rod includes a rod body and a first lifting lug and a second lifting lug installed at both ends of the rod body; the test device includes: An upright supporting frame, comprising a relatively fixed base plate and a top plate; A loader is connected below the top plate; An adjustment plate is horizontally positioned below the loader; A sensor assembly, with its two ends connected to the loader and the adjusting plate respectively, measures the force applied by the loader to the adjusting plate; and The guiding device includes: Two upright guide columns are fixed to the base plate; The lower connecting assembly is configured to connect a first lug of an upright traction rod located between the two guide posts to the lower part of the two guide posts; and An upper connecting assembly is provided, with its upper part connected to an adjusting plate and its lower part connected to a second lifting lug, and the two guide posts slidably passing through the upper connecting assembly and the adjusting plate.

2. The experimental apparatus according to claim 1, characterized in that, The upper connection component includes: Two transverse sleeves, each of the transverse sleeves having a mounting hole adapted to receive one end of the first lifting lug; and Two force-applying components are connected between two transverse sleeves and an adjusting plate, and each guide post slides through the transverse sleeve and the force-applying component.

3. The experimental apparatus according to claim 2, characterized in that, Each of the force-applying components includes: An upright sleeve extends upward from the transverse sleeve through the adjusting plate, and the outer side of the upright sleeve has a radially outwardly protruding boss that abuts against the lower surface of the adjusting plate; and A fastening mechanism is releasably mounted on the end of the upright sleeve that extends out of the adjusting plate, the adjusting plate cooperating with the fastening mechanism or boss to lift or press down the upright sleeve and the transverse sleeve.

4. The experimental apparatus according to claim 3, characterized in that, The fastening mechanism includes a fastener with internal threads, which is threadedly engaged with the end of the upright sleeve and abuts against the upper surface of the adjusting plate.

5. The test apparatus according to any one of claims 1 to 4, characterized in that, It also includes a detachable fixing plate fixed above the base plate, the fixing plate being connected to the lower end of the guide device.

6. The experimental apparatus according to claim 5, characterized in that, The base plate is provided with a recess, and the test device also includes a stop member disposed in the recess. The stop member passes through the fixing plate and fixes the fixing plate to the base plate.

7. The test apparatus according to claim 6, characterized in that, The lower connecting assembly includes two lower sleeves respectively fitted onto the guide post, each lower sleeve being configured such that one end abuts against the fixed plate and the other end abuts against the lower surface of the second lifting lug.

8. The test apparatus according to claim 7, characterized in that, The lower connecting assembly also includes two upper sleeves respectively fitted onto the guide post, each upper sleeve being threadedly engaged with the guide post and abutting against the upper surface of the second lifting lug.

9. The experimental apparatus according to claim 1, characterized in that, The sensor assembly includes a sensor, a first connecting part, and a second connecting part. One end of the sensor is detachably connected to the loader via the first connecting part, and the other end is detachably connected to the adjustment plate via the second connecting part.

10. The experimental apparatus according to claim 1, characterized in that, The loader is a hydraulic cylinder.

11. The test apparatus according to claim 1, characterized in that, At least one strain gauge is attached to the main body of the tie rod, and the strain gauge is used to measure the deformation of the main body of the tie rod during loading.

12. A method for bidirectional loading test of a traction rod, characterized in that, Using the testing apparatus as described in any one of claims 1 to 11, the testing method includes the steps of: S1: Install the traction rod in the test device, and adjust the position of the adjusting plate, the upper connecting assembly and the traction rod so that they are aligned with the vertical guide column to establish an axial loading path along the vertical direction; S2: Control the loader to apply tension and / or pressure to the traction rod along the axial direction of the guide column; S3: During the loading process, the applied load value is measured and recorded by the sensor assembly; S4: Based on the load value and the corresponding test settings, obtain one or more performance parameters of the traction rod under the load.

13. The test method according to claim 12, characterized in that, S4 is: to obtain the correspondence between the load value and the strain signal output by the strain gauge, so as to establish the load-strain curve of the traction rod or calculate the strain coefficient.

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