Metal tensile device with strain compensation function and micro-deformation measurement method

Abstract

The present application belongs to the technical field of material deformation measurement, and particularly relates to a metal stretching device with strain compensation function and a micro-deformation measurement method, which comprises a mounting table and two supporting columns installed at the top of the mounting table at intervals, a suspended platform, a tension sensor and two clamps are vertically arranged in sequence between the two supporting columns, an air source assembly for clamping of the clamps is arranged outside the mounting table, a driving assembly for vertical movement of the suspended platform is arranged on the mounting table, two supporting wheels are respectively installed at both ends of the suspended platform, and traction ropes are arranged at the bottom of the two supporting wheels; two groups of second air cylinders are respectively connected to the ends of the traction ropes, and the two groups of second air cylinders are connected to the air source assembly. The present application increases the stretching effect when the test piece deforms, compensates for the deformation amount when the test piece deforms, enhances the continuity of load transmission, and can improve the stability and data consistency of the experimental process.

Description

Technical Field

[0001] This invention belongs to the field of material deformation measurement technology, specifically relating to a metal tensile device with strain compensation function and a micro-deformation measurement method. Background Technology

[0002] Tensile tests on metallic materials, by analyzing the tensile curves, can directly or indirectly obtain a series of key indicators that determine the application characteristics of the material, such as elastic modulus, yield strength and tensile strength. Among them, elastic modulus is used to measure the ease with which a material produces elastic deformation, reflects the inherent stiffness of the material, and determines the amount of elastic displacement of a part under stress.

[0003] In existing metal bar tensile tests, the tensile device drives a lead screw via a brake motor, which in turn drives two clamps to stretch the specimen. For example, a Chinese invention patent with publication number CN120992318A describes a metal rod tensile test device. By setting up a tensile component, when the slider rises, the nylon rope pulls the piston ring, compressing the air inside the second chamber and allowing it to enter the first chamber through a groove. This pushes the support rod to apply an upward thrust to the slider. This prevents the downward force exerted by the metal rod on the slider surface through the crossbeam from damaging the thread groove of the high-precision lead screw, thus reducing the accuracy of the high-precision lead screw. When the slider slides downward, the engagement of the ratchet and pawl drives the gear to rotate, preventing interference with the high-precision lead screw's ability to continue driving the slider downward.

[0004] In the initial stage of a tensile test, after the specimen reaches the deformation condition, it begins to yield slightly. At this time, because the lead screw maintains a constant feed rate, the instantaneous tensile force it experiences decreases and cannot match the load required for material deformation. Existing thrust adjustment mechanisms are unable to effectively compensate for the lack of tensile force in this stage, which may affect the continuity of load transfer and adversely affect the stability of the experimental process and the consistency of data. Summary of the Invention

[0005] The purpose of this invention is to provide a metal tensile device with strain compensation function and a micro-deformation measurement method, which can increase the tensile effect when the specimen is deformed, to compensate for the deformation of the specimen during deformation, enhance the continuity of load transfer, and improve the stability of the experimental process and the consistency of data.

[0006] The specific technical solution adopted by this invention is as follows:

[0007] A strain-compensating metal tensioning device includes a mounting platform and two support columns spaced apart on the top of the mounting platform. A suspended platform, a tension sensor, and two clamps are vertically arranged sequentially between the two support columns. An air source assembly for clamping the clamps is provided outside the mounting platform. A drive assembly for vertical movement of the suspended platform is provided on the mounting platform. The device also includes:

[0008] Two support wheels are respectively installed at both ends of the suspended platform, and a traction cable is provided at the bottom of each support wheel;

[0009] Two sets of second cylinders are respectively connected to both ends of the traction cable, and both sets of second cylinders are connected to the air source assembly;

[0010] A load-bearing plate is disposed between the drive assembly and the second cylinder;

[0011] When the specimen deforms, the second cylinder, under the pressure provided by the air source assembly, lifts the traction cable along the traction direction of the two clamps. The two support wheels and the suspended platform drive the two clamps away from each other to compensate for the deformation of the specimen. The difference in tension at both ends of the traction cable is used to reflect the degree of offset of the adjacent support wheels.

[0012] As an alternative, the traction cable is folded into two sections at the bottom of the support wheel, and strain gauges are fixed to the outer sides of both sections. When there is a difference in tension between the two sections of the traction cable, the degree of this difference is used to reflect the degree of offset of their adjacent support wheels.

[0013] A level sensor is installed between the two sets of second cylinders. When the detection value of the level sensor is not zero, the lifting amount of the piston rod of the two sets of second cylinders will be different.

[0014] When the absolute value of the level sensor exceeds a preset threshold, an alarm signal is triggered, which indicates that the two sets of the second cylinders need to enter the calibration state.

[0015] As an alternative, the end of the traction cable is sequentially connected to a hinge seat and a movable plate. Guide tubes and wing plates are installed at intervals on the movable plate. The guide tubes are used to connect to the drive assembly, and the bottom of the wing plates is connected to the piston rod of the second cylinder.

[0016] When the second cylinder moves the movable plate, the traction cable changes its angle relative to the movable plate along the hinge axis of the hinge seat.

[0017] As an alternative, a concave seat is fixed to the top of the movable plate, and an elastic membrane is installed between two adjacent movable plates through the concave seat. The elastic membrane is used to calibrate the horizontal state between the two adjacent movable plates.

[0018] When the lifting amount of the two sets of second cylinder piston rods differs, the horizontal state of the two adjacent movable plates is broken, and the elastic membrane tilts relative to the horizontal plane.

[0019] As an optional solution, the clamp includes a connecting rod, a base and a jaw connected vertically in sequence. The jaw has a concave opening, and two first cylinders are symmetrically installed at both ends of the concave opening. The piston rods of the two first cylinders extend out of the interior, and each piston rod is connected to a clamping plate.

[0020] When the air source assembly supplies air, the piston rods of the two first cylinders drive the two clamping plates to move closer to each other until the two clamping plates clamp the specimen to provide a preset clamping force.

[0021] As an optional solution, a flange plate is installed on the outside of the jaws, and a support member and a locking plate are provided at intervals at the end of the flange plate away from the adjacent jaws, and a limiting rod is inserted between the support member and the locking plate;

[0022] When the specimen is clamped, the limiting rod extends in a folded shape to the outside of the gap between two adjacent clamping plates to horizontally limit the specimen.

[0023] As an optional solution, the air source assembly includes an air tank located outside the mounting platform and a compressor connected to the air tank. The air outlet of the air tank is sequentially connected to an air supply pipe and an electric air valve. The air supply pipe is connected to the first cylinder, and the electric air valve is signal connected to two foot switches.

[0024] One of the foot switches is pressed down to the open position to control the electric gas valve, and the other foot switch is pressed down to the closed position to control the electric gas valve.

[0025] As an alternative, the drive assembly includes a lead screw spaced apart on the mounting platform and a guide rail for guiding the lifting and lowering of the second cylinder. Both the lead screw and the guide rail extend into the interior of adjacent support columns. A brake motor is driven to the bottom of the lead screw, and the load plate is connected to the thread on the outside of the lead screw through a threaded hole.

[0026] When the lead screw rotates forward, the lead screw raises the load plate and the second cylinder, and the second cylinder drives the traction cable to raise the support wheel and the suspended platform;

[0027] When the lead screw reverses, it lowers the load plate and the second cylinder, which in turn drives the traction cable to lower the support wheel and the suspended platform.

[0028] As an alternative, a top crossbeam is connected between the tops of the two support columns, and a lifting ring is installed on the outside of the top crossbeam. A folding flap is slidably provided on the side of the two support columns that are close to each other.

[0029] The suspended platform has louvers running through both ends. When the suspended platform is raised or lowered, the louvers are used to reduce dust entering the opening of the support column.

[0030] A method for measuring micro-deformation under tensile stress in metal with strain compensation function, applied to a metal tensile device with strain compensation function, includes the following steps:

[0031] Before the specimen deforms, the distance sensor detects the relative height of the load-bearing plate, and this relative height is defined as... ;

[0032] When the specimen deforms, the compressed air inside the second cylinder expands, lifting the traction cable along the traction direction of the two clamps. The two support wheels and the suspended platform drive the two clamps away from each other to compensate for the deformation of the specimen until the specimen returns to the preset load state.

[0033] At the same time, the tension of the traction cable is monitored, and a tension difference threshold is set. If the absolute value of the tension difference between the two traction cables exceeds the tension difference threshold, the controller sends a message through the operating system to remind the staff to replace the traction cable.

[0034] If the absolute value of the tension difference between the two traction cables does not exceed the tension difference threshold, the distance sensor is activated to record the load plate's position. Relative height value at time At this point, the vertical deformation of the specimen is calculated using the relative height value. The deformation of the specimen is set as follows: ;

[0035] The deformation of the specimen is detected by a distance sensor for each deformation until the specimen breaks. The deformation data is combined with time to plot a deformation-time curve, which reflects the degree of deformation of the specimen at different times under tensile conditions.

[0036] The technical effects achieved by this invention are as follows:

[0037] In this invention, an external air source provides compressed air, and a proportional valve adjusts the supply of compressed air. This causes multiple second cylinders to extend when the instantaneous tensile force on the specimen decreases. The compressed air inside the second cylinders expands, briefly lifting the specimen along the traction direction of the clamps. The traction cable, support wheel, and suspended platform distribute the load, preventing load concentration and keeping the two clamps away from each other. This increases the tensile force when the specimen deforms, compensating for the deformation during specimen deformation, enhancing the continuity of load transfer, and improving the stability and data consistency of the experimental process.

[0038] This invention uses strain gauges in the deformation compensation area to monitor the tension of the traction cable in real time. At the same time, a tension difference threshold is set. When the absolute value of the tension difference between two strain gauges exceeds the tension difference threshold, it indicates that the deformation of the two sections of the traction cable has reached the point where correction is needed. This invention can promptly detect when the traction cable in that area has reached its fatigue limit. The controller sends a message through the operating system to remind the staff to replace the traction cable.

[0039] This invention uses a horizontal sensor to monitor the horizontal state between the piston rods of two sets of second cylinders. When the absolute value of the horizontal sensor exceeds a preset threshold, an alarm signal is triggered to indicate that the two sets of second cylinders need to enter a calibration state. It can actively detect the imbalance state in the area used to compensate for deformation and remind the staff to correct the structure of the imbalance state. Attached Figure Description

[0040] Figure 1 This is a schematic diagram of the metal stretching device in Embodiment 1 of the present invention;

[0041] Figure 2 This is a cross-sectional view of the metal stretching device in Embodiment 1 of the present invention;

[0042] Figure 3 This is a schematic diagram of the drive component in Embodiment 1 of the present invention;

[0043] Figure 4 This is a top view of the suspended platform in Embodiment 1 of the present invention;

[0044] Figure 5 This is a cross-sectional view of the fixture in Embodiment 1 of the present invention;

[0045] Figure 6 This is a schematic diagram of the flange plate in Embodiment 1 of the present invention;

[0046] Figure 7 This is a side view of the support wheel in Embodiment 1 of the present invention;

[0047] Figure 8 This is a top view of the support wheel in Embodiment 1 of the present invention;

[0048] Figure 9 This is a system block diagram of the controller controlling the signal transmission state in Embodiment 1 of the present invention;

[0049] Figure 10 This is a flowchart of a metal tensile micro-deformation measurement method with strain compensation function according to Embodiment 2 of the present invention.

[0050] The attached diagram lists the components represented by each number as follows:

[0051] 1. Chassis; 2. Mounting platform; 3. Support column; 4. Suspended platform; 401. Slide rail; 5. Tension sensor; 6. Clamp; 601. Connecting rod; 602. Base; 603. Jaw; 604. First cylinder; 605. Clamping plate; 606. Flange plate; 607. Support component; 608. Locking plate; 609. Limiting rod; 7. Compressor; 8. Air tank; 9. Electric air valve; 10. Input 11. Air pipe; 12. Foot switch; 13. Brake motor; 14. Lead screw; 15. Guide rail; 16. Support wheel; 17. Traction cable; 18. Second cylinder; 19. Load plate; 20. Hinge seat; 21. Movable plate; 22. Guide tube; 23. Wing plate; 24. Strain gauge; 25. Horizontal sensor; 26. Concave seat; 27. Elastic membrane; 28. Top crossbeam; 29. ​​Lifting ring; 20. Perforated flap. Detailed Implementation

[0052] To make the objectives and advantages of this invention clearer, the invention will be specifically described below with reference to embodiments. It should be understood that the following text is merely used to describe one or more specific embodiments of the invention and does not strictly limit the scope of protection specifically claimed by the invention.

[0053] Example 1:

[0054] like Figures 1-9 As shown, a strain-compensating metal tensile device includes a mounting platform 2 and two support columns 3 that are bolted to the top of the mounting platform 2. A suspended platform 4, a tension sensor 5, and two clamps 6 are vertically arranged between the two support columns 3. When clamping the specimen, the suspended platform 4 is driven by external power to the mounting platform 2, so that the suspended platform 4 drives one of the clamps 6 to a set height. The specimen is then vertically placed into the two clamps 6. The clamping force is provided by compressed air outside the mounting platform 2. At this time, the two clamps 6 clamp the two ends of the specimen respectively, completing the clamping action.

[0055] When testing the specimen, the mounting platform 2 provides driving force to move the suspended platform 4 vertically at a constant speed. The suspended platform 4 drives the two clamps 6 to move away from each other slowly, realizing the function of vertically tensile the specimen under a preset load. Meanwhile, the tension sensor 5 records the instantaneous tension value borne by the specimen in real time, which is used to plot the load-time curve.

[0056] It should be noted that the tensile force value itself is paired with the strain data of the specimen for analysis, which is used to describe the state of the specimen:

[0057] (1) Elastic deformation stage: The upper limit point where the tensile force value is proportional to the strain data is defined as the proportional limit; the maximum stress point at which the specimen can completely return to its original shape after unloading is defined as the elastic limit.

[0058] (2) Yield stage: The maximum tensile force value before the first drop in tensile force is defined as the upper yield point; the minimum value of relatively stable tensile force fluctuation during the yielding process is defined as the lower yield point;

[0059] (3) Maximum tension state: During the stretching process, the tension sensor 5 records the maximum value of the tension, which is called the maximum load.

[0060] See attached document Figure 1 , Figure 5 and Figure 10 When compressed air is required, the compressor 7, which is electrically connected to the controller outside the mounting platform 2, starts to draw in and compress air. At the same time, it opens the electric valve of the air tank 8 to pump the compressed air into the air tank 8. The air outlet of the air tank 8 is connected to the air supply pipe 10 and the electric air valve 9 in sequence through the connector. The controller is electrically connected to the electric air valve 9 and two foot switches 11. The operator can step on the two foot switches 11 to a predetermined height to trigger the relay of the corresponding foot switch 11 to the set position signal. The controller controls the electric air valve 9 to open or close.

[0061] When a foot switch 11 is pressed down to trigger the position signal, the controller controls the electric air valve 9 to switch to the open state. Since the air supply pipe 10 is connected to the first cylinder 604 through the connector, the air pressure inside the first cylinder 604 is less than the air pressure inside the air tank 8, causing some of the compressed air in the air tank 8 to flow into the first cylinder 604 along the air supply pipe 10. The piston rod of the first cylinder 604 extends to provide clamping force until the specimen is clamped and then stops.

[0062] Or, if the internal air pressure of the first cylinder 604 is greater than the internal air pressure of the air tank 8, some of the compressed air in the first cylinder 604 will flow out to reduce the clamping force until the test piece is released and the clamping state is released.

[0063] When the other foot switch 11 is pressed down to the position, it controls the electric air valve 9 to switch to the closed state, so that the first cylinder 604 switches to the closed state to keep the clamping force within the set range.

[0064] See attached document Figure 2 , Figure 3 and Figure 5 In this embodiment, the clamp 6 includes a connecting rod 601, a base 602 and a jaw 603 connected vertically in sequence. The jaw 603 has a concave opening, and two first cylinders 604 are symmetrically installed at both ends of the concave opening by bolts. The piston rods of the two first cylinders 604 extend out of the interior, and the piston rods are connected to clamping plates 605.

[0065] When compressed air is supplied, the piston rods of the two first cylinders 604 drive the two clamping plates 605 to move closer to each other until the two clamping plates 605 clamp the specimen, which is used to provide a preset clamping force so that the two clamps 6 respectively clamp the two ends of the specimen.

[0066] See attached document Figure 3 and Figure 6 A flange plate 606 is installed on the outside of the jaws 603 by screws. The end of the flange plate 606 away from the adjacent jaws 603 is integrally milled to form a support 607. A folded limiting rod 609 is placed on the support 607. When the specimen is clamped, the limiting rod 609 extends in a folded shape to the outside of the gap between two adjacent clamping plates 605 to horizontally limit the specimen.

[0067] After the limit rod 609 is in place, since the support 607 is connected to the locking plate 608 by bolts, the bolts can be tightened to clamp the limit rod 609 with the flange plate 606, thereby realizing the locking function of the limit rod 609.

[0068] See attached document Figure 2 , Figure 3 and Figure 9 When driving force is required, the brake motor 12, which is electrically connected to the controller, is activated inside the chassis 1 to provide driving force. The screw 13 and guide rail 14 are rotatably mounted on the mounting platform 2 via bearings. Both the screw 13 and guide rail 14 extend into the interior of the adjacent support column 3. The output end of the brake motor 12 is connected to the gear at the lower end of the screw 13 through gear transmission, so that the screw 13 rotates under the action of driving force.

[0069] Meanwhile, load plates 18 are connected to the bottom of both ends of the suspended platform 4. Both load plates 18 are connected to the threads on the outside of the lead screw 13 through threaded holes. Under the transmission action of the threads, the suspended platform 4 drives one of the clamps 6 above to rise and fall to the specified height.

[0070] As an optional embodiment, both ends of the suspended platform 4 are connected by slide rails 401. When one end of the suspended platform 4 is driven, the suspended platform 4 slides up along the slide rails 401 to prevent it from becoming unbalanced. Two brake motors 12 can be correspondingly set on the two slide rails 401. The two brake motors 12 synchronously drive two lead screws 13 to provide driving force at the same time.

[0071] Alternatively, the number of brake motors 12 can be set to one, which transmits the driving force synchronously to two lead screws 13 through a worm gear, so that the two ends of the suspended platform 4 can be raised and lowered synchronously.

[0072] See attached document Figure 2 , Figure 3 and Figure 9The suspended platform 4 has two support wheels 15 installed at both ends via a pivot. Each of the two support wheels 15 has a traction cable 16 at its bottom. Since the upper surfaces of the two load plates 18 are fixed with two sets of second cylinders 17 connected to the traction cable 16 by bolts, when the load plates 18 are raised or lowered, the driving force can be transmitted to the suspended platform 4 through the support wheels 15, the traction cable 16, and the second cylinders 17.

[0073] When the lead screw 13 rotates forward, the lead screw 13 raises the load plate 18 and the second cylinder 17, and the second cylinder 17 drives the traction cable 16 to raise the support wheel 15 and the suspended platform 4.

[0074] When the lead screw 13 reverses, it lowers the load plate 18 and the second cylinder 17. The second cylinder 17 drives the traction cable 16 to lower the support wheel 15 and the suspended platform 4.

[0075] When the specimen deforms, the load plate 18 rises at a constant speed under the action of the driving force. The feed distance provided by the load plate 18 is less than the distance of the specimen deformation, so the instantaneous tensile force value of the specimen is less than the preset tensile force value. The difference between the instantaneous tensile force value and the preset tensile force value needs to be compensated. Therefore, in this embodiment, the second cylinder 17 is connected to the air tank 8 through a proportional valve. The internal pressure of the second cylinder 17 is maintained within a preset range that can support the clamp 6.

[0076] When the instantaneous tensile force of the specimen decreases, the compressed air inside the second cylinder 17 expands, lifting the traction cable 16 along the traction direction of the two clamps 6. The two support wheels 15 and the suspended platform 4 drive the two clamps 6 to move away from each other, which is used to compensate for the deformation of the specimen until the specimen returns to the preset load state. The degree of tension difference at both ends of the traction cable 16 can be used to reflect the degree of offset of the adjacent support wheels 15.

[0077] See attached document Figure 4 , Figure 7 and Figure 8 The traction cable 16 is connected to a hinge seat 19 and a movable plate 20 in sequence at its end. The bottom of the hinge seat 19 is welded to the side of the movable plate 20, and the hinge shaft of the hinge seat 19 is connected to the traction cable 16 through a steel wire clamp. When the specimen is stretched, in this embodiment, the movable plate 20 is fixed to the piston rod of the second cylinder 17 by bolts. Under the drive of the piston rod of the second cylinder 17, the movable plate 20 slides along the guide rail 14, and the traction cable 16 changes its angle relative to the movable plate 20 along the hinge shaft of the hinge seat 19 to prevent interference with the movable plate 20 in the lifting state.

[0078] As an optional embodiment, guide tubes 21 and wing plates 22 are welded at intervals on the movable plate 20. During lifting and lowering, the guide tubes 21 are sleeved onto the guide rail 14 to increase the area of ​​the guide rail 14 for straightening the movable plate 20. The bottom of the wing plate 22 is connected to the piston rod of the second cylinder 17 via a nut. See [reference needed]. Figure 3 and Figure 8Each support wheel 15 is supported by four second cylinders 17, which can distribute the vertical support force required when the suspended platform 4 is raised to eight second cylinders 17. The load on a single second cylinder 17 is small, thereby reducing the pressure requirement of the compressed air in the second cylinder 17 and reducing the compression power required to form the compressed air.

[0079] See attached document Figure 7 , Figure 8 and Figure 9 The top of the movable plate 20 is fixed with a concave seat 25 by screws. An elastic diaphragm 26 is installed between two adjacent movable plates 20 through the concave seat 25. During installation, the two ends of the elastic diaphragm 26 are respectively glued to the opening of the concave seat 25, and a level sensor 24 is fixed in the middle of the elastic diaphragm 26 with glue. When the lifting amount of the piston rods of the two sets of second cylinders 17 is different, the horizontal state of the two adjacent movable plates 20 is broken, the detection value of the level sensor 24 is not zero, and the elastic diaphragm 26 is tilted relative to the horizontal plane. At this time, the elastic diaphragm 26 is used to calibrate the horizontal state between the two adjacent movable plates 20.

[0080] Specifically, when the horizontal sensor 24 is tilted toward one end of the elastic membrane 26, the detection value is set to a positive value, and when the horizontal sensor 24 is tilted toward the other end of the elastic membrane 26, the detection value is set to a negative value.

[0081] When the detection value of the horizontal sensor 24 is positive, the lifting amount of the piston rod of one set of second cylinders 17 is greater than the lifting amount of the piston rod of the other set of second cylinders 17.

[0082] When the detection value of the horizontal sensor 24 is negative, the lifting amount of the piston rod of the other set of second cylinders 17 is greater than the lifting amount of the piston rod of the other set of second cylinders 17.

[0083] When the absolute value of the level sensor 24 exceeds the preset threshold (which is manually input by the controller), an alarm signal is triggered. This alarm signal is used to indicate that the two sets of second cylinders 17 need to enter the calibration state. It can actively detect the unbalanced state of the area used to compensate for deformation and remind the staff to correct the unbalanced structure.

[0084] See attached document Figure 7 , Figure 8 and Figure 9 The traction cable 16 is folded into two sections at the bottom relative to the support wheel 15. Strain gauges 23 are glued to the outer sides of both sections of the traction cable 16. Both ends of the strain gauges 23 are firmly glued, while the middle is spaced from the traction cable 16. They can be subjected to tensile deformation. When the strain gauges 23 deform, their own resistance changes, which in turn changes the current signal of the detection circuit, so that the tension of the traction cable 16 can be monitored in real time.

[0085] When the tension of one strain gauge 23 is greater than that of the other strain gauge 23, the load of the support wheel 15 shifts toward the traction cable 16 corresponding to one strain gauge 23.

[0086] When the tension of another strain gauge 23 is greater than that of one strain gauge 23, the load of the support wheel 15 shifts toward the traction cable 16 corresponding to the other strain gauge 23.

[0087] At the same time, a tension difference threshold is set. When the absolute value of the tension difference between the two strain gauges 23 exceeds the tension difference threshold, it indicates that the deformation of the two sections of the traction cable 16 has reached a point where correction is needed. The controller sends a message through the operating system to remind the staff to replace the traction cable 16.

[0088] See attached document Figure 1 A top crossbeam 27 is bolted between the tops of the two support columns 3, and a lifting ring 28 is threaded on the outside of the top crossbeam 27. When installing or transporting the tensioning device, the top crossbeam 27 supports the two support columns 3 to prevent the two support columns 3 from tilting. The lifting ring 28 can be connected to a crane through a hook to complete the lifting and moving.

[0089] After installation, folding blades 29 are slidably installed on the side of the two support columns 3 that are close to each other. The folding blades 29 are passed through both ends of the suspended platform 4. When the suspended platform 4 is raised or lowered, part of the folding blades 29 are squeezed into a folded state by the suspended platform 4, and the other part of the folding blades 29 are pulled into an unfolded state by the suspended platform 4. The two parts of the folding blades 29 are used to reduce dust entering the opening of the support column 3.

[0090] Example 2:

[0091] like Figure 10 As shown, a method for measuring the micro-deformation of metal under tensile stress with strain compensation function, applied to a metal tensile device with strain compensation function provided in Embodiment 1, includes the following steps:

[0092] Before the specimen deforms, the load-bearing plate 18 records the vertical height value between itself and the movable plate 20 via a distance sensor. This vertical height value is defined as... ;

[0093] When the specimen deforms, the load plate 18 rises at a constant speed under the action of the driving force. The feed distance provided by the load plate 18 is less than the distance of the specimen deformation, so the instantaneous tensile force value of the specimen is less than the preset tensile force value. The difference between the instantaneous tensile force value and the preset tensile force value needs to be compensated. Therefore, in this embodiment, the second cylinder 17 is connected to the air tank 8 through a proportional valve. Under the action of external compressed air, the internal pressure of the second cylinder 17 is maintained within a preset range that can support the clamp 6.

[0094] Strain compensation: When the instantaneous tensile force of the specimen decreases, the compressed air inside the second cylinder 17 expands and lifts the traction cable 16 along the traction direction of the two clamps 6. The two support wheels 15 and the suspended platform 4 drive the two clamps 6 to move away from each other, which is used to compensate for the deformation of the specimen until the specimen returns to the preset load state.

[0095] Condition monitoring: When the tension of one strain gauge 23 is greater than that of the other strain gauge 23, the load of the support wheel 15 shifts toward the traction cable 16 corresponding to the strain gauge 23.

[0096] When the tension of another strain gauge 23 is greater than that of one strain gauge 23, the load of the support wheel 15 shifts toward the traction cable 16 corresponding to the other strain gauge 23.

[0097] At the same time, a tension difference threshold is set. When the absolute value of the tension difference between the two strain gauges 23 exceeds the tension difference threshold, it indicates that the deformation of the two sections of the traction cable 16 has reached a point where correction is needed. The controller sends a message through the operating system to remind the staff to replace the traction cable 16.

[0098] Measurement begins: If the absolute value of the tension difference between the two strain gauges 23 does not exceed the tension difference threshold, the distance sensor is activated to record the distance between the load plate 18 and the movable plate 20. Vertical height value at time Since the vertical displacement of the movable plate 20 is equal to the deformation compensation amount, the vertical deformation of the specimen can be calculated by two vertical height values.

[0099] The deformation of the specimen is set as follows: ;

[0100] Repeated measurement: The deformation of the specimen is recorded each time by a distance sensor until the specimen breaks. The deformation data is combined with time to plot the deformation-time curve, which reflects the degree of deformation of the specimen at different times under tensile conditions.

[0101] The above description is merely an optional embodiment of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention. Structures, devices, and operating methods not specifically described or explained in this invention, unless otherwise specified or limited, shall be implemented according to conventional means in the art.

Claims

1. A metal tensioning device with strain compensation function, comprising a mounting platform (2) and two support columns (3) spaced apart on the top of the mounting platform (2), wherein a suspended platform (4), a tension sensor (5), and two clamps (6) are vertically arranged sequentially between the two support columns (3), an air source assembly for clamping by the clamps (6) is provided outside the mounting platform (2), and a drive assembly for vertical movement of the suspended platform (4) is provided on the mounting platform (2), characterized in that, Also includes: Two support wheels (15) are respectively installed at both ends of the suspended platform (4), and traction cables (16) are provided at the bottom of both support wheels (15). Two sets of second cylinders (17) are respectively connected to both ends of the traction cable (16), and both sets of second cylinders (17) are connected to the air source assembly; A load-bearing plate (18) is disposed between the drive assembly and the second cylinder (17); When the specimen deforms, the second cylinder (17) lifts the traction cable (16) along the traction direction of the two clamps (6) under the pressure provided by the air source assembly. The two support wheels (15) and the suspended platform (4) drive the two clamps (6) to move away from each other, which is used to compensate for the deformation of the specimen. The tension difference at both ends of the traction cable (16) is used to reflect the offset of the adjacent support wheels (15).

2. The metal tensile device with strain compensation function according to claim 1, characterized in that: The traction cable (16) is folded into two sections at the bottom relative to the support wheel (15). Strain gauges (23) are fixed on the outer sides of both sections of the traction cable (16). When there is a difference in tension on the two sections of the traction cable (16), the degree of the difference is used to reflect the degree of offset of the adjacent support wheel (15). A level sensor (24) is provided between the two sets of second cylinders (17). When the detection value of the level sensor (24) is not zero, the lifting amount of the piston rods of the two sets of second cylinders (17) will be different. When the absolute value of the detection value of the level sensor (24) exceeds the preset threshold, an alarm signal is triggered. The alarm signal is used to indicate that the two sets of the second cylinders (17) need to enter the calibration state.

3. A metal tensile device with strain compensation function according to claim 1, characterized in that: The end of the traction cable (16) is connected in sequence to a hinge seat (19) and a movable plate (20). A guide tube (21) and a wing plate (22) are installed on the movable plate (20) at intervals. The guide tube (21) is used to connect the drive assembly. The bottom of the wing plate (22) is connected to the piston rod of the second cylinder (17). When the second cylinder (17) moves the movable plate (20), the traction cable (16) changes its angle relative to the movable plate (20) along the hinge axis of the hinge seat (19).

4. A metal tensile device with strain compensation function according to claim 3, characterized in that: A concave seat (25) is fixed to the top of the movable plate (20), and an elastic membrane (26) is installed between two adjacent movable plates (20) through the concave seat (25). The elastic membrane (26) is used to calibrate the horizontal state between the two adjacent movable plates (20). When the lifting amount of the piston rods of the two sets of second cylinders (17) is different, the horizontal state of the two adjacent movable plates (20) is broken, and the elastic membrane (26) tilts relative to the horizontal plane.

5. A metal tensile device with strain compensation function according to claim 1, characterized in that: The clamp (6) includes a connecting rod (601), a base (602) and a jaw (603) connected vertically in sequence. The jaw (603) has a concave opening, and two first cylinders (604) are symmetrically installed at both ends of the concave opening. The piston rods of the two first cylinders (604) extend out of the interior, and the piston rods of the two first cylinders (604) are connected to a clamping plate (605). When the air source assembly supplies air, the piston rods of the two first cylinders (604) drive the two clamping plates (605) to move closer to each other until the two clamping plates (605) clamp the specimen to provide a preset clamping force.

6. A metal tensile device with strain compensation function according to claim 5, characterized in that: A flange plate (606) is installed on the outside of the jaws (603). A support member (607) and a locking plate (608) are provided at a distance from the end of the flange plate (606) away from the adjacent jaws (603). A limiting rod (609) is inserted between the support member (607) and the locking plate (608). When the specimen is clamped, the limiting rod (609) extends in a folded shape to the outside of the gap between two adjacent clamping plates (605) to horizontally limit the specimen.

7. A metal tensile device with strain compensation function according to claim 5, characterized in that: The gas source assembly includes a gas tank (8) located outside the mounting platform (2) and a compressor (7) connected to the gas tank (8). The gas outlet of the gas tank (8) is connected in sequence to a gas supply pipe (10) and an electric gas valve (9). The gas supply pipe (10) is connected to the first cylinder (604). The electric gas valve (9) is signal connected to two foot switches (11). One of the foot switches (11) is pressed down to control the electric air valve (9) to switch to the open state, and the other foot switch (11) is pressed down to control the electric air valve (9) to switch to the closed state.

8. A metal tensile device with strain compensation function according to claim 1, characterized in that: The drive assembly includes a lead screw (13) spaced on the mounting platform (2) and a guide rail (14) for guiding the second cylinder (17) to rise and fall. Both the lead screw (13) and the guide rail (14) extend into the interior of the adjacent support column (3). The bottom of the lead screw (13) is connected to a brake motor (12). The load plate (18) is connected to the thread on the outside of the lead screw (13) through a threaded hole. When the lead screw (13) rotates forward, the lead screw (13) raises the load plate (18) and the second cylinder (17), and the second cylinder (17) drives the traction cable (16) to lift the support wheel (15) and the suspended platform (4). When the lead screw (13) reverses, the lead screw (13) lowers the load plate (18) and the second cylinder (17), and the second cylinder (17) drives the traction cable (16) to lower the support wheel (15) and the suspended platform (4).

9. A metal tensile device with strain compensation function according to claim 1, characterized in that: A top beam (27) is connected between the tops of the two support columns (3), and a lifting ring (28) is installed on the outside of the top beam (27). A folding flap (29) is slidably provided on the side of the two support columns (3) that are close to each other. The suspended platform (4) has folding blades (29) running through both ends. When the suspended platform (4) is raised or lowered, the folding blades (29) are used to reduce dust entering the opening of the support column (3).

10. A method for measuring micro-deformation under tensile stress in metals with strain compensation function, applied to the metal tensile device with strain compensation function as described in any one of claims 1-9, characterized in that, Includes the following steps: Before the specimen deforms, the distance sensor detects the relative height value of the load plate (18), the relative height value being defined as... ; When the specimen deforms, the compressed air inside the second cylinder (17) expands and lifts the traction cable (16) along the traction direction of the two clamps (6). The two support wheels (15) and the suspended platform (4) drive the two clamps (6) to move away from each other, which is used to compensate for the deformation of the specimen until the specimen returns to the preset load state. At the same time, the tension of the traction cable (16) is monitored and a tension difference threshold is set. If the absolute value of the tension difference between the two traction cables (16) exceeds the tension difference threshold, the controller sends a message to remind the staff to replace the traction cable (16). If the absolute value of the tension difference between the two traction cables (16) does not exceed the tension difference threshold, the distance sensor is activated to record the distance of the load plate (18) at the [location / time]. Relative height value at time At this point, the vertical deformation of the specimen is calculated using the relative height value. The deformation of the specimen is set as follows: ; The deformation of the specimen is detected by a distance sensor for each deformation until the specimen breaks. The deformation data is combined with time to plot a deformation-time curve, which reflects the degree of deformation of the specimen at different times under tensile conditions.

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