Special tensile test device for seamless steel pipe

Abstract

The invention discloses a tensile test device special for a seamless steel pipe, and relates to the technical field of material mechanical property testing, the tensile test device comprises a base, a first clamp mechanism and a second clamp mechanism, the base is provided with a first inner cavity, a second inner cavity and an outer cavity, a partition plate is arranged between the first inner cavity and the second inner cavity, the second inner cavity is communicated with the outer cavity, and the first clamp mechanism is connected with the second clamp mechanism. A first clamp mechanism is arranged in the outer cavity, a second clamp mechanism is arranged in the second inner cavity, a connecting column is further fixedly arranged on the base, the second clamp mechanism comprises a positioning cylinder, a positioning rod, a driving cylinder and a driving mechanism, two annular plates are fixedly arranged at the upper end and the lower end of the positioning cylinder, and a plurality of first sliding grooves extending in the radial direction are evenly distributed in the annular plates in the circumferential direction. Sliding plates are arranged in the first sliding grooves in a sliding mode, and a positioning rod is arranged between the two sliding plates, corresponding in position, on the two annular plates in a sliding mode. The replacement rate of the steel pipe is improved and the test efficiency of the steel pipe tensile test is further improved.

Description

Technical Field

[0001] This invention relates to the field of material mechanical property testing technology, specifically a tensile testing device for seamless steel pipes. Background Technology

[0002] In tensile testing of seamless steel pipes, traditional tensile testing equipment has the following disadvantages:

[0003] First, mechanical clamps require changing clamping blocks according to the specifications of the steel pipe, and the clamping process requires manual positioning and clamping, which is cumbersome and time-consuming, thus seriously affecting the test efficiency of tensile testing. Second, traditional wedge clamping mechanisms usually have line clamping or point clamping surfaces, which makes the steel pipe less resistant to displacement after clamping, and the steel pipe may deform or the specimen may loosen during the tensile test. Third, traditional clamping and disassembly require many manual assistance steps, and each test takes a long time, resulting in low test efficiency.

[0004] Therefore, it is necessary to provide a tensile testing device specifically for seamless steel pipes to solve the problems mentioned in the background art. Summary of the Invention

[0005] To achieve the above objectives, the present invention provides the following technical solution: a tensile testing device for seamless steel pipes, comprising a base, a first clamping mechanism, and a second clamping mechanism. The base has a first inner cavity, a second inner cavity, and an outer cavity. A partition is provided between the first inner cavity and the second inner cavity. The second inner cavity is connected to the outer cavity. The first clamping mechanism is provided in the outer cavity, and the second clamping mechanism is provided in the second inner cavity. A connecting column is also fixedly provided on the base. The first clamping mechanism consists of two clamping blocks. Two inclined surfaces are symmetrically provided on the side wall of the outer cavity. An inclined surface is provided on each clamping block that slides with the inclined surface. The tops of the two clamping blocks are attached to the second clamping mechanism.

[0006] Preferably, the second clamping mechanism includes a positioning cylinder, a positioning rod, a driving cylinder, and a driving mechanism. Two annular plates are fixedly arranged at the upper and lower ends of the positioning cylinder. Multiple radially extending slide grooves are evenly distributed in the annular plates along the circumference. A slide plate is slidably arranged in the slide groove. A positioning rod is slidably arranged between two slide plates that are correspondingly positioned on the upper and lower annular plates. The driving cylinder is fixedly arranged on the positioning cylinder, and a driving mechanism is provided in the driving cylinder.

[0007] Preferably, the slide plate has a second groove along the radial direction of the annular plate, and the upper and lower ends of the positioning rod are fixedly provided with sliders, which are slidably disposed along the second groove;

[0008] Limiting grooves are provided on both sides of the slide groove, and limiting blocks are fixedly provided on both sides of the slide plate. The limiting blocks are slidably arranged along the limiting grooves.

[0009] Preferably, the driving mechanism includes a push plate, a turntable, and a hydraulic cylinder. The push plate is slidably disposed in the driving cylinder, the turntable is rotatably disposed on the push plate, and a hydraulic cylinder is fixedly disposed on the driving cylinder. The piston rod end of the hydraulic cylinder is fixedly connected to the push plate, and a spring for resetting is disposed between the push plate and the driving cylinder.

[0010] Preferably, the push plate has a plurality of radially extending straight grooves evenly distributed along the circumference;

[0011] The turntable has multiple arc-shaped grooves along its circumference; a guide rod is fixedly installed on the side of the positioning rod near the push plate, and the guide rod passes through the straight groove and slides along the arc-shaped groove.

[0012] Preferably, the inner side of the drive cylinder is provided with a plurality of spiral grooves along the circumference, and the outer side of the turntable is provided with a plurality of guide blocks along the circumference, the guide blocks being slidably disposed along the spiral grooves.

[0013] Preferably, a push rod and multiple support rods are fixedly provided at the bottom of the push plate, and multiple connecting plates are fixedly provided between the multiple support rods and the push rod, and the multiple support rods slide through the annular plate at the upper end of the positioning cylinder.

[0014] Preferably, a limiting plate is fixedly provided on the clamping block; a sliding groove three parallel to the inclined surface three is provided on the inclined surface one, the limiting plate is slidably provided along the sliding groove three, and a spring two is provided between the limiting plate and the end of the sliding groove three.

[0015] Preferably, a plurality of T-shaped limiting rods are fixedly provided on the top of the drive cylinder; the limiting rods slide through the partition and extend into the first inner cavity, and a spring is fixedly provided between the limiting rods and the partition.

[0016] Compared with the prior art, the present invention provides a tensile testing device for seamless steel pipes, which has the following beneficial effects: The present invention sets up a push rod and a connecting plate so that when the steel pipe contacts the push rod and the connecting plate, it can be pushed to slide upward, thereby pushing the push plate to slide upward. The sliding of the push plate further drives multiple positioning rods to converge synchronously through a turntable, a drive cylinder and a guide rod, thereby achieving adaptive clamping of the steel pipe. At the same time, the steel pipe is automatically positioned during the clamping process. After clamping is completed, the second clamping mechanism can move downward with the tensile process and push the clamping block in the first clamping mechanism to slide along the inclined plane, thereby forming a self-locking clamping, improving the clamping stability and effectively preventing the steel pipe from shifting during the tensile test. In addition, the setting of spring one, spring two and spring three can enable the drive mechanism and the second clamping mechanism to quickly reset, so that the steel pipe can be quickly released after the tensile test, thereby improving the steel pipe replacement rate and further improving the test efficiency of the steel pipe tensile test. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0018] Figure 2 This is a schematic diagram of the internal structure of the base in this invention;

[0019] Figure 3 This is a schematic diagram of the structure of the second clamping mechanism in this invention;

[0020] Figure 4 This is a schematic diagram of the positioning cylinder and the driving cylinder in this invention;

[0021] Figure 5 This is a schematic diagram of the push plate in this invention;

[0022] Figure 6 This is a schematic diagram of the positioning rod in this invention;

[0023] In the diagram: 1. Base; 11. First inner cavity; 12. Second inner cavity; 13. Outer cavity; 14. Connecting column; 15. Inclined surface one; 16. Slide three; 2. First clamping mechanism; 21. Clamping block; 22. Inclined surface two; 23. Limiting plate; 3. Second clamping mechanism; 31. Positioning cylinder; 311. Annular plate; 312. Slide one; 313. Slide plate; 314. Slide two; 315. Limiting block; 32. Positioning rod; 321. Slider; 322. Guide rod; 33. Drive cylinder; 331. Spiral groove; 332. Limiting rod; 333. Spring three; 34. Drive mechanism; 341. Push plate; 342. Turntable; 343. Hydraulic cylinder; 344. Spring one; 345. Straight groove; 346. Arc groove; 347. Guide block; 348. Push rod; 349. Connecting plate. Detailed Implementation

[0024] Please see Figures 1-6 In this embodiment of the invention, a tensile testing device for seamless steel pipes includes a base 1, a first clamping mechanism 2, and a second clamping mechanism 3. The base 1 has a first inner cavity 11, a second inner cavity 12, and an outer cavity 13. A partition is provided between the first inner cavity 11 and the second inner cavity 12. The second inner cavity 12 is connected to the outer cavity 13. The first clamping mechanism 2 is located in the outer cavity 13, and the second clamping mechanism 3 is located in the second inner cavity 12. A connecting column 14 is also fixedly mounted on the base 1. The first clamping mechanism 2 consists of two clamping blocks 21, symmetrically arranged on the sidewalls of the outer cavity 13. The fixture has two inclined surfaces 15. The clamping block 21 is provided with an inclined surface 22 that slides with the inclined surface 15. A limiting plate 23 is fixedly provided on the clamping block 21. A sliding groove 3 16 parallel to the inclined surface 15 is provided on the inclined surface 15. The limiting plate 23 slides along the sliding groove 3 16. A spring 2 is provided between the end of the limiting plate 23 and the end of the sliding groove 3 16. The tops of the two clamping blocks 21 are attached to the second clamping mechanism 3. The fixture also includes a loading frame, which is a rigid structure for applying tensile loads. The base 1 is connected to the loading frame through a connecting column 14.

[0025] In this embodiment, the second clamping mechanism 3 includes a positioning cylinder 31, a positioning rod 32, a driving cylinder 33, and a driving mechanism 34. Two annular plates 311 are fixedly arranged at the upper and lower ends of the positioning cylinder 31. Multiple radially extending slide grooves 312 are evenly distributed in the annular plates 311 along the circumference. Slide plates 313 are slidably arranged in the slide grooves 312. A positioning rod 32 is slidably arranged between two slide plates 313 at corresponding positions on the upper and lower annular plates 311. The driving cylinder 33 is fixedly arranged on the positioning cylinder 31, and the driving mechanism 34 is arranged in the driving cylinder 33.

[0026] The slide plate 313 has a second slide groove 314 radially along the annular plate 311. The positioning rod 32 has sliders 321 fixedly installed at its upper and lower ends. The sliders 321 slide along the second slide groove 314. Limiting grooves are opened on both sides of the first slide groove 312. Limiting blocks 315 are fixedly installed on both sides of the slide plate 313. The limiting blocks 315 slide along the limiting grooves.

[0027] In addition, the first slide groove 312 is a slide groove with an opening at one end, that is, the slide plate 313 can slide out of the first slide groove 312, and its sliding is restricted by the limiting block 315 and the limiting groove. The second slide groove 314 is an annular groove, that is, the sliding of the slider 321 along the second slide groove 314 is a limited sliding. When the slider 321 slides to the end of the second slide groove 314, it will drive the slide plate 313 to slide along the first slide groove 312.

[0028] Specifically, a sliding plate 313 is provided in the annular plate 311 so that the sliding plate 313 can slide to the outside of the annular plate 311, thereby effectively increasing the sliding stroke of the positioning rod 32 and increasing the clamping range of the positioning rod 32. This enables the second clamping mechanism 3 to effectively position and clamp various types of steel pipes.

[0029] In this embodiment, the driving mechanism 34 includes a push plate 341, a turntable 342, and a hydraulic cylinder 343. The push plate 341 is slidably disposed in the driving cylinder 33, the turntable 342 is rotatably disposed on the push plate 341, and the hydraulic cylinder 343 is fixedly disposed on the driving cylinder 33. The piston rod end of the hydraulic cylinder 343 is fixedly connected to the push plate 341, and a spring 344 for resetting is disposed between the push plate 341 and the driving cylinder 33.

[0030] The push plate 341 has multiple radially extending straight grooves 345 evenly distributed along its circumference; the turntable 342 has multiple arc-shaped grooves 346 circumferentially formed along its circumference; a guide rod 322 is fixedly installed on the side of the positioning rod 32 near the push plate 341, the guide rod 322 passes through the straight grooves 345 and slides along the arc-shaped grooves 346; the inner side of the drive cylinder 33 has multiple spiral grooves 331 circumferentially formed along its inner side, and multiple guide blocks 347 are fixedly installed on the outer side of the turntable 342 circumferentially, the guide blocks 347 slide along the spiral grooves 345... 31. Sliding arrangement; a push rod 348 and multiple support rods are fixedly arranged at the bottom of the push plate 341, and multiple connecting plates 349 are fixedly arranged between the multiple support rods and the push rod 348, and the multiple support rods slide through the annular plate 311 at the upper end of the positioning cylinder 31; multiple T-shaped limiting rods 332 are fixedly arranged at the top of the drive cylinder 33; the limiting rods 332 slide through the partition and extend into the first inner cavity 11, and a spring 333 is fixedly arranged between the limiting rods 332 and the partition.

[0031] During implementation, the two ends of the steel pipe to be subjected to the tensile test are aligned with two bases 1 set on the loading frame. Then, the two bases 1 are driven to move closer together, so that the two ends of the steel pipe extend into the outer cavity 13 and the second inner cavity 12 of the two bases 1 respectively. When the end of the steel pipe contacts the push rod 348 and multiple connecting plates 349, as the two bases 1 move closer, the steel pipe will push the push rod 348 to slide upward, which in turn will drive the push plate 341 to slide upward. The upward sliding of the push plate 341 will further drive the turntable 342 to slide upward. At this time, the guide block 347 will slide along the spiral groove 331, thereby driving the turntable 342 to rotate, causing the guide rod 322 to slide along the arc groove 346 and the straight groove 345, thereby causing the multiple positioning rods 32 to slide together. During this process, when one of the multiple positioning rods 32 contacts the steel pipe first, the positioning rod 32 will continue to push the steel pipe to slide together until all the positioning rods 32 are in close contact with the steel pipe. At this time, the positioning rod 32 will no longer slide, and the push plate 341 will also no longer slide. Then, the... The hydraulic cylinder 343 actively applies a pulling force to the push plate 341, giving the push plate 341 a continuous upward sliding force, which in turn gives the multiple positioning rods 32 a continuous clamping force, thereby completing the positioning and clamping of the steel pipe. After clamping, the two bases 1 on the loading frame are driven away. At this time, since the second clamping mechanism 3 fully clamps the steel pipe, the steel pipe will pull the positioning cylinder 31 and the driving cylinder 33 to slide downward together. That is, the second clamping mechanism 3 will slide downward along the second inner cavity 12. At this time, the positioning cylinder 31 will push the two... The clamping blocks 21 slide along the inclined plane 15, causing the two clamping blocks 21 to approach each other. When the two clamping blocks 21 contact the steel pipe and clamp the steel pipe, a tensile test can be performed on the steel pipe. During the test, as the base 1 stretches the steel pipe, the second clamping mechanism 3 will apply a pushing force to the clamping blocks 21, thereby ensuring that the clamping blocks 21 always have clamping force and form a self-locking clamping mechanism. This makes the clamping stability higher and effectively prevents the steel pipe from shifting. This completes the rapid positioning and clamping of the steel pipe and effectively improves the test efficiency and the accuracy of the test results.

[0032] In addition, in the initial state, springs 344, 333, and 344 are all in a compressed state, causing the push plate 341 to abut against the annular plate 311 at the upper end of the positioning cylinder 31 in the initial state. The clamping block 21 is located at the highest end of the outer cavity 13, and the second clamping mechanism 3, i.e., the drive cylinder 33, abuts against the partition. After the tensile test is completed, the two bases 1 are driven to move closer, and the second clamping mechanism 3 slides upward under the action of spring 333. The clamping block 21 is then abutted against the partition under the action of spring 2. The lower plate slides upward synchronously, thereby releasing the steel pipe. Then, the hydraulic cylinder 343 is adjusted to passive extension and retraction, that is, no tension is applied to the push plate 341 and the sliding of the push plate 341 is not interfered with. At this time, the push plate 341 will slide downward under the action of the spring 344, that is, the push plate 341 and the turntable 342 will reset, and the positioning rod 32 will also reset. This allows the first clamping mechanism 2 and the second clamping mechanism 3 to quickly release the steel pipe, which is convenient for the next tensile test. This achieves rapid clamping and rapid replacement of the steel pipe, effectively improving the test efficiency.

[0033] In summary, when this invention is implemented, by setting push rod 348 and connecting plate 349, when the steel pipe contacts push rod 348 and connecting plate 349, it can be pushed to slide upward, thereby pushing push plate 341 to slide upward. The sliding of push plate 341 further drives multiple positioning rods 32 to converge synchronously through turntable 342, drive cylinder 33 and guide rod 322, thereby realizing adaptive clamping of steel pipe. At the same time, automatic positioning of steel pipe is completed during clamping. After clamping is completed, the second clamping mechanism 3 can move down with the stretching process and push the clamping block 21 in the first clamping mechanism 2 to slide along inclined plane 15, thereby forming self-locking clamping, improving clamping stability and effectively preventing displacement of steel pipe during tensile test. In addition, setting spring 1 344, spring 2 and spring 333 can enable drive mechanism 34 and second clamping mechanism 3 to quickly reset, so that steel pipe can be quickly released after tensile test, thereby improving the replacement rate of steel pipe and further improving the test efficiency of steel pipe tensile test.

[0034] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A tensile testing device specifically for seamless steel pipes, characterized in that, The device includes a base (1), a first clamping mechanism (2) and a second clamping mechanism (3). The base (1) has a first inner cavity (11), a second inner cavity (12) and an outer cavity (13). A partition is provided between the first inner cavity (11) and the second inner cavity (12). The second inner cavity (12) is connected to the outer cavity (13). The first clamping mechanism (2) is provided in the outer cavity (13). The second clamping mechanism (3) is provided in the second inner cavity (12). A connecting column (14) is also fixedly provided on the base (1). The first clamping mechanism (2) is composed of two clamping blocks (21). Two inclined surfaces (15) are symmetrically opened on the side wall of the outer cavity (13). An inclined surface (22) is provided on the clamping block (21) to slide with the inclined surface (15). The tops of the two clamping blocks (21) are attached to the second clamping mechanism (3).

2. The tensile testing device for seamless steel pipes according to claim 1, characterized in that, The second clamping mechanism (3) includes a positioning cylinder (31), a positioning rod (32), a driving cylinder (33), and a driving mechanism (34). The positioning cylinder (31) has two annular plates (311) fixedly installed at its upper and lower ends. The annular plates (311) have multiple radially extending slide grooves (312) evenly distributed along the circumference. Slide plates (313) are slidably installed in the slide grooves (312). The positioning rod (32) is slidably installed between the two slide plates (313) at corresponding positions on the upper and lower annular plates (311). The driving cylinder (33) is fixedly installed on the positioning cylinder (31), and the driving mechanism (34) is installed in the driving cylinder (33).

3. The tensile testing device for seamless steel pipes according to claim 2, characterized in that, The slide plate (313) has a second slide groove (314) along the radial direction of the annular plate (311), and the positioning rod (32) has a slider (321) fixedly installed at both ends. The slider (321) slides along the second slide groove (314). Limiting grooves are provided on both sides of the slide groove (312), and limiting blocks (315) are fixedly provided on both sides of the slide plate (313). The limiting blocks (315) are slidably arranged along the limiting grooves.

4. The tensile testing device for seamless steel pipes according to claim 2, characterized in that, The drive mechanism (34) includes a push plate (341), a turntable (342), and a hydraulic cylinder (343). The push plate (341) is slidably disposed in the drive cylinder (33), and the turntable (342) is rotatably disposed on the push plate (341). The hydraulic cylinder (343) is fixedly disposed on the drive cylinder (33). The piston rod end of the hydraulic cylinder (343) is fixedly connected to the push plate (341), and a spring (344) for resetting is disposed between the push plate (341) and the drive cylinder (33).

5. The tensile testing device for seamless steel pipes according to claim 4, characterized in that, The push plate (341) has a plurality of radially extending straight grooves (345) evenly distributed along the circumference; The turntable (342) has multiple arc-shaped grooves (346) along its circumferential direction; The positioning rod (32) is fixedly provided with a guide rod (322) on the side near the push plate (341). The guide rod (322) passes through the straight groove (345) and slides along the arc groove (346).

6. The tensile testing device for seamless steel pipes according to claim 4, characterized in that, The drive cylinder (33) has multiple spiral grooves (331) circumferentially opened on the inner side, and multiple guide blocks (347) are fixedly arranged circumferentially on the outer side of the turntable (342). The guide blocks (347) are slidably arranged along the spiral grooves (331).

7. The tensile testing device for seamless steel pipes according to claim 4, characterized in that, The bottom of the push plate (341) is fixedly provided with a push rod (348) and a plurality of support rods. A plurality of connecting plates (349) are fixedly provided between the plurality of support rods and the push rod (348), and the plurality of support rods slide through the annular plate (311) at the upper end of the positioning cylinder (31).

8. The tensile testing device for seamless steel pipes according to claim 1, characterized in that, A limiting plate (23) is fixedly provided on the clamping block (21); A groove three (16) parallel to the inclined surface one (15) is provided on the inclined surface one (15). The limiting plate (23) is slidably arranged along the groove three (16), and a spring two is provided between the end of the limiting plate (23) and the groove three (16).

9. A tensile testing device for seamless steel pipes according to claim 2, characterized in that, The top of the drive cylinder (33) is fixedly provided with a plurality of T-shaped limiting rods (332); The limiting rod (332) slides through the partition and extends into the first inner cavity (11), and a spring (333) is fixedly provided between the limiting rod (332) and the partition.

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