A steel pipe closed clamping structure and a hardness testing device and method having the same

Abstract

The application discloses a steel pipe closed clamping structure and relates to the technical field of steel pipe processing. The steel pipe closed clamping structure comprises a box body, a sealing cover and a clamping ring. The test cavity of the box body is arranged in a closed structure, and only an openable opening is arranged on the left side of the test cavity. The hardness of the steel pipe can be effectively tested. When the steel pipe is cracked, safety protection is performed. On the basis, the clamping ring is installed on the left side of the test cavity and in the sealing cover. After the sealing cover moves to open the opening of the test cavity, the entering of the steel pipe is not interfered. After the sealing cover seals the opening of the test cavity, the telescopic clamping of the steel pipe is realized. When clamping, the outer clamping plate is triggered to clamp the outer surface of the steel pipe and the inner clamping plate is triggered to clamp the inner wall surface of the steel pipe through the contact between the clamping ring and the steel pipe. The steel pipe is clamped from the inside and the outside. The deviation of the steel pipe from the detection head in an instant is avoided, and the accuracy of the test is affected.

Description

Technical Field

[0001] This invention relates to the field of steel pipe processing technology, and in particular to a closed clamping structure for steel pipes. Background Technology

[0002] The hardness testing of stainless steel must take into account its mechanical properties, which are related to the performance and quality of deformation, stamping, cutting, and other processing operations performed on stainless steel. Therefore, all seamless steel pipes must undergo mechanical property testing.

[0003] In mechanical production, various types of round tubular steel pipes are needed to clamp and fix workpieces, placing them on a fixed workbench. When testing the hardness of round tubular steel pipes, an indenter is usually pressed into the interior of the sample, and the hardness is calculated by observing the damage or deformation on the surface of the steel pipe.

[0004] However, current testing methods rely on screws to fix the steel pipe to its outer surface, resulting in poor stability. When the indenter presses down with gravity, the steel pipe may shift upon contact with the indenter, affecting test accuracy. Furthermore, some defective samples are prone to shattering into fragments under significant stress. This shattering is a direct cause of brittle fracture due to internal material inhomogeneity or embrittlement (manufacturing quality, improper heat treatment, operating temperature, mechanical fatigue, chemical corrosion, etc., all alter the internal crystal structure, leading to inhomogeneity or embrittlement). Therefore, current steel pipe hardness testing devices still pose risks of low accuracy and high hazard. Summary of the Invention

[0005] One of the objectives of this invention is to address the problems of low accuracy and high risk in existing technologies for testing the hardness of steel pipes.

[0006] The second objective of this invention is to provide a hardness testing device with a steel pipe sealed clamping structure.

[0007] The third objective of this invention is to provide a method for sealing and clamping steel pipes.

[0008] To achieve one of the above objectives, the present invention adopts the following technical solution: a steel pipe sealed clamping structure, comprising: a box body, a sealing cover, and a clamping ring.

[0009] The chamber contains a test cavity, and the right side of the test cavity has an opening for a steel pipe to enter.

[0010] The sealing cover is installed on the left side of the housing to open or close the opening communicating with the test chamber. The sealing cover has a telescopic motor, and the clamping rings are arranged on the left and right sides of the test chamber. The clamping ring on the right side is connected to the telescopic motor and is telescopically embedded in the sealing cover. The clamping ring is provided with: an outer clamping plate, an inner clamping plate, a stress plate, and a pressure spring.

[0011] The outer clamping plate is distributed around the outside of the clamping ring, and the outer clamping plate is slidably connected to the clamping plate by an outer spring. The inner clamping plate is distributed around the inside of the clamping ring, and there is a gap between the outer clamping plate and the inner clamping plate. The inner clamping plate is slidably connected to the clamping plate by an inner spring.

[0012] The stress plate is slidably connected to the telescopic cavity of the clamping ring, and the outer surface portion of the stress plate is located on the gap side. The stress plate has an outer pressure plate and an inner pressure plate.

[0013] The outer pressure plate is hooked to the outer clamping plate, and the contact surface between the outer pressure plate and the outer clamping plate is an inclined surface. The inner pressure plate is hooked to the inner clamping plate, and the contact surface between the inner pressure plate and the inner clamping plate is an inclined surface.

[0014] The pressure spring is connected to the stress plate.

[0015] In the above technical solution, when testing the hardness of a steel pipe, the sealing cover on the side of the chamber is first pushed so that the sealing cover moves and opens the opening on the left side of the test chamber. Then the steel pipe is pushed into the test chamber through the opening.

[0016] Push the sealing cover back so that it re-seals the opening on the left side of the test chamber. Then, start the telescopic motor in the sealing cover to push the clamping ring inside the sealing cover toward the right end of the steel pipe and push the steel pipe so that the clamping rings on both sides of the test chamber clamp the steel pipe.

[0017] During the clamping process, the steel pipe extends into the gap between the outer and inner clamping plates of the clamping ring and comes into contact with the stress plate. Driven by the telescopic motor, the stress plate, which is pressed against the steel pipe, moves towards the telescopic cavity of the clamping ring, compressing the pressure spring. At the same time, the movement of the stress plate pulls the outer pressure plate to squeeze the outer clamping plate and pulls the inner pressure plate to squeeze the outer clamping plate. Under the action of the inclined surface, the outer pressure plate squeezes the outer clamping plate and moves radially inward to clamp the outer surface of the steel pipe, while the inner pressure plate squeezes the inner clamping plate and moves radially outward to clamp the inner wall surface of the steel pipe, thus tightly fixing the steel pipe inside and out.

[0018] Furthermore, in this embodiment of the invention, the clamping ring on the right side of the test chamber is rotatably connected to the telescopic motor, and the clamping ring on the left side of the test chamber is fixedly connected to the rotary motor inside the box.

[0019] Furthermore, in this embodiment of the invention, the sealing cover is slidably installed on the left side of the housing, and the sealing cover opens the opening on the right side of the test chamber by sliding sideways.

[0020] Furthermore, in this embodiment of the invention, a handle is installed on the outer surface of the sealing cover.

[0021] Furthermore, in this embodiment of the invention, the opposing surfaces of the outer clamping plate and the inner clamping plate are planar or arc-shaped surfaces, and a rubber strip is installed on the planar or arc-shaped surface.

[0022] Furthermore, in this embodiment of the invention, the gap between the outer clamping plate and the inner clamping plate is larger than the wall thickness of the steel pipe.

[0023] The beneficial effects of this invention are:

[0024] This invention, by designing the test chamber of the housing as a sealed structure with an openable opening only on the left side, effectively provides safety protection in the event of a steel pipe bursting during hardness testing. Furthermore, by installing clamping rings on the left side of the test chamber and inside the sealing cover, the steel pipe can be inserted without interference after the sealing cover moves to open the test chamber opening. Even after the sealing cover seals the test chamber opening, it allows for telescopic clamping of the steel pipe. During clamping, the contact between the clamping rings and the steel pipe triggers the outer clamping plate to hold the outer surface of the steel pipe and the inner clamping plate to hold the inner wall surface of the steel pipe, thus clamping the steel pipe from both inside and out. This prevents displacement of the steel pipe at the moment of contact with the testing head, which would affect the accuracy of the test.

[0025] To achieve the second objective mentioned above, the present invention adopts the following technical solution: a hardness testing device, wherein it has the steel pipe sealed clamping structure described in one of the above objectives.

[0026] Furthermore, in this embodiment of the invention, a hydraulic cylinder is fixedly installed on the housing, the hydraulic cylinder is powered by a detection head, the detection head is located on the test chamber, and the hydraulic cylinder pushes the detection head downward so that the detection head presses on the steel pipe to perform a hardness test.

[0027] Furthermore, in this embodiment of the invention, the telescopic end of the hydraulic cylinder is connected to a guide plate, a transmission screw is laterally rotatably connected to the guide plate, a connecting block is threaded onto the transmission screw, and the detection head is installed under the connecting block.

[0028] Furthermore, in this embodiment of the invention, an operation display system is installed outside the housing. The operation display system is connected to the telescopic motor, rotary motor, hydraulic cylinder, detection head, and power motor connected to the transmission screw via wired or wireless communication.

[0029] After the steel pipe is securely fixed, the hydraulic cylinder is activated to move the detection head to the surface of the steel pipe. Pressure is applied to the steel pipe through the detection head to perform a hardness test. The hydraulic cylinder or detection head then acquires the pressure value. The hydraulic cylinder is then activated to reset the detection head. Next, the transmission screw is activated to move the connecting block and the detection head to another position on the steel pipe. The hardness test on the steel pipe is repeated by moving the detection head down, thereby obtaining multiple sets of pressure values. Finally, these multiple sets of pressure values ​​are transmitted to the operation display system, which converts the pressure values ​​into a curve analysis graph, thereby determining the pressure value of the tested steel pipe and obtaining more accurate test results.

[0030] Furthermore, in this embodiment of the invention, a center adjustment component is rotatably installed in the housing, and the center adjustment component is located in the test chamber.

[0031] The center adjustment assembly has a power shaft, the central axis of which is at the same height and intersects with the central axis of the clamping ring.

[0032] The power shaft is connected to a swing arm, and each of the upper and lower ends of the swing arm is connected to a guide wheel. A guide post is provided between the guide wheels, and the guide post has a tapered structure that is narrower on the inside and wider on the outside.

[0033] There is a space between the upper and lower guide columns for the steel pipe to pass through. After the steel pipe enters the test chamber, it will pass through the space between the upper and lower guide columns.

[0034] In practice, after placing the steel pipe into the test chamber, due to the different sizes of the steel pipes, it is often found that the steel pipe cannot be coaxial with the clamping ring. For example, if the ring formed by the outer clamping plate is smaller than the aperture of the test chamber, the steel pipe will have difficulty entering the gap between the outer and inner clamping plates. Therefore, the ring formed by the outer clamping plate is usually larger than the aperture of the test chamber. This requires the clamping ring to be large enough, but the gap between the outer and inner clamping plates will also be too large. When clamping smaller steel pipes, the clamping of the outer wall of the steel pipe is prone to instability, so further improvements are needed.

[0035] To address this, a central adjustment component is installed. After the steel pipe passes through the upper and lower guide columns, the power shaft drives the swing arm to rotate, causing the lower guide column to lift the steel pipe while the upper guide column presses it down. This method can accommodate steel pipes of different sizes. Furthermore, because the upper and lower guide columns rotate around the center of the power shaft, and the central axis of the power shaft is at the same height and intersects with the central axis of the clamping ring, the steel pipe, after being lifted, is coaxial with the clamping ring. This facilitates the smooth entry of the steel pipe into the gap between the outer and inner clamping plates during clamping, reducing the size requirements of the clamping ring and making the clamping of the steel pipe by the outer clamping plate more stable.

[0036] To achieve the third objective mentioned above, the present invention adopts the following technical solution: a steel pipe sealing clamping method, applied to the pipe sealing clamping structure described in the first objective of the invention or the hardness testing device described in the second objective of the invention, comprising the following steps:

[0037] When testing the hardness of the steel pipe, first push the sealing cover on the side of the chamber, so that the sealing cover moves and opens the opening on the left side of the test chamber. Then push the steel pipe into the test chamber through the opening.

[0038] Push the sealing cover back so that it re-seals the opening on the left side of the test chamber. Then, start the telescopic motor in the sealing cover to push the clamping ring inside the sealing cover toward the right end of the steel pipe and push the steel pipe so that the clamping rings on both sides of the test chamber clamp the steel pipe.

[0039] During the clamping process, the steel pipe extends into the gap between the outer and inner clamping plates of the clamping ring and comes into contact with the stress plate. Driven by the telescopic motor, the stress plate, which is pressed against the steel pipe, moves towards the telescopic cavity of the clamping ring, compressing the pressure spring. At the same time, the movement of the stress plate pulls the outer pressure plate to squeeze the outer clamping plate and pulls the inner pressure plate to squeeze the outer clamping plate. Under the action of the inclined surface, the outer pressure plate squeezes the outer clamping plate and moves radially inward to clamp the outer surface of the steel pipe, while the inner pressure plate squeezes the inner clamping plate and moves radially outward to clamp the inner wall surface of the steel pipe, thus tightly fixing the steel pipe inside and out.

[0040] Furthermore, in this embodiment of the invention, after the steel pipe is tightly fixed, the hydraulic cylinder is activated to push the detection head to the surface of the steel pipe. The detection head applies pressure to the steel pipe to perform a hardness test. Then, the hydraulic cylinder or the detection head obtains the pressure value. Next, the hydraulic cylinder is activated to reset the detection head. Then, the transmission screw is activated to push the connecting block and the detection head to another position on the steel pipe. The hardness test of the steel pipe is repeated by moving the detection head down, thereby obtaining multiple sets of pressure values. Finally, the multiple sets of pressure values ​​are transmitted to the operation display system. The operation display system converts the pressure values ​​into a curve analysis graph, thereby determining the pressure value of the tested steel pipe. Attached Figure Description

[0041] Figure 1 This is a plan view of the hardness testing device according to an embodiment of the present invention.

[0042] Figure 2 This is a side view of the hardness testing device according to an embodiment of the present invention.

[0043] Figure 3 This is a schematic diagram of the hardness testing device with a closed steel pipe clamping structure according to an embodiment of the present invention.

[0044] Figure 4 This is a side view of the clamping ring according to an embodiment of the present invention.

[0045] Figure 5 This is a schematic diagram of the side movement effect of the hardness testing device according to an embodiment of the present invention.

[0046] Figure 6 This is a schematic diagram of the hardness testing device after clamping a steel pipe according to an embodiment of the present invention.

[0047] Figure 7 This is a schematic diagram illustrating the motion effect of the clamping ring clamping the steel pipe in an embodiment of the present invention.

[0048] Figure 8 This is a schematic diagram illustrating the installation effect of the center adjustment component after it is installed inside the hardness testing device in an embodiment of the present invention.

[0049] Figure 9 This is a three-dimensional schematic diagram of the center adjustment component in an embodiment of the present invention.

[0050] Figure 10 This is a schematic diagram illustrating the effect of the steel pipe passing through the central adjustment component in an embodiment of the present invention.

[0051] Figure 11 This is a three-dimensional schematic diagram of the steel pipe passing through the central adjustment component according to an embodiment of the present invention.

[0052] Figure 12 This is a schematic diagram illustrating the motion effect of the center adjustment component in an embodiment of the present invention.

[0053] In the attached diagram

[0054] 10. Housing; 11. Test chamber; 12. Rotary motor

[0055] 13. Operation display system

[0056] 20. Sealing cap; 21. Telescopic motor; 22. Handle

[0057] 30. Clamping ring; 31. Outer clamping plate; 32. Outer spring

[0058] 33. Inner clamping plate; 34. Inner spring; 35. Telescopic cavity

[0059] 36. Stress plate; 37. External pressure plate; 38. Internal pressure plate

[0060] 39. Compression spring

[0061] 40. Hydraulic cylinder; 41. Guide plate; 42. Transmission screw

[0062] 43. Connecting block 44. Detection head

[0063] 50. Center adjustment assembly; 51. Power shaft; 52. Swing arm

[0064] 53. Guide wheel 54. Guide column

[0065] 100. Steel pipe Detailed Implementation

[0066] To make the objectives, technical solutions, and advantages of the present invention clear and complete, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only some, not all, embodiments of the present invention, and are merely illustrative of the embodiments of the present invention. They are not intended to limit the embodiments of the present invention. All other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0067] In the description of this invention, it should be noted that the terms "center," "middle," "upper," "lower," "left," "right," "inner," "outer," "top," "bottom," "side," "vertical," and "horizontal," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "a," "first," "second," "third," "fourth," "fifth," and "sixth" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0068] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0069] For purposes of simplicity and illustration, the principles of the embodiments are described primarily by way of example. In the following description, numerous specific details are set forth to provide a thorough understanding of the embodiments. However, it will be apparent to those skilled in the art that these embodiments may not be limited to these specific details in practice. In some instances, well-known steel pipe sealing clamping methods and structures have not been described in detail to avoid unnecessarily obscuring these embodiments. Furthermore, all embodiments can be used in combination with each other.

[0070] Example 1:

[0071] A steel pipe sealed clamping structure, wherein, as Figure 1-3 As shown, it includes: box body 10, sealing cover 20, and clamping ring 30.

[0072] like Figure 3 As shown, the housing 10 has a test chamber 11, and the right side of the test chamber 11 has an opening for the steel pipe 100 to enter.

[0073] A sealing cover 20 is installed on the left side of the housing 10 to open or close the opening communicating with the test chamber 11. The sealing cover 20 has a telescopic motor 21, and clamping rings 30 are arranged on the left and right sides of the test chamber 11. The clamping ring 30 on the right side is connected to the telescopic motor 21 and is telescopically embedded in the sealing cover 20. The clamping ring 30 is provided with: an outer clamping plate 31, an inner clamping plate 33, a stress plate 36, and a pressure spring 39.

[0074] like Figure 4 As shown, the outer clamping plate 31 is distributed around the outside of the clamping ring 30, and the outer clamping plate 31 is slidably connected to the clamping plate by the outer spring 32. The inner clamping plate 33 is distributed around the inside of the clamping ring 30, and there is a gap between the outer clamping plate 31 and the inner clamping plate 33. The size of the gap between the outer clamping plate 31 and the inner clamping plate 33 is greater than the wall thickness of the steel pipe 100. The inner clamping plate 33 is slidably connected to the clamping plate by the inner spring 34.

[0075] The stress plate 36 is slidably connected to the telescopic cavity 35 of the clamping ring 30, and the outer surface portion of the stress plate 36 is located on the gap side. The stress plate 36 has an outer pressure plate 37 and an inner pressure plate 38.

[0076] The outer pressure plate 37 is hooked to the outer clamping plate 31, and the contact surfaces of the outer pressure plate 37 and the outer clamping plate 31 are inclined surfaces. The inner pressure plate 38 is hooked to the inner clamping plate 33, and the contact surfaces of the inner pressure plate 38 and the inner clamping plate 33 are inclined surfaces.

[0077] The pressure spring 39 is connected to the stress plate 36.

[0078] Implementation steps:

[0079] like Figure 5 As shown, when testing the hardness of the steel pipe 100, the sealing cover 20 on the side of the box 10 is pushed first, so that the sealing cover 20 moves and opens the opening on the left side of the test chamber 11. Then the steel pipe 100 is pushed into the test chamber 11 through the opening.

[0080] like Figure 6 As shown, push the sealing cover 20 back so that the sealing cover 20 re-seals the opening on the left side of the test chamber 11. Then start the telescopic motor 21 in the sealing cover 20 to push the clamping ring 30 inside the sealing cover 20 toward the right end of the steel pipe 100 and push the steel pipe 100 so that the clamping rings 30 on both sides of the test chamber 11 clamp the steel pipe 100.

[0081] like Figure 7As shown, during the clamping process, the steel pipe 100 extends into the gap between the outer clamping plate 31 and the inner clamping plate 33 in the clamping ring 30 and comes into contact with the stress plate 36. Under the push of the telescopic motor 21, the stress plate 36, which is pressed against the steel pipe 100, moves towards the telescopic cavity 35 of the clamping ring 30, compressing the pressure spring 39. At the same time, the stress plate 36 moves to pull the outer pressure plate 37 to squeeze the outer clamping plate 31 and pull the inner pressure plate 38 to squeeze the outer clamping plate 31. Under the action of the inclined surface, the outer pressure plate 37 squeezes the outer clamping plate 31 and moves radially inward to clamp the outer surface of the steel pipe 100, while the inner pressure plate 38 squeezes the inner clamping plate 33 and moves radially outward to clamp the inner wall surface of the steel pipe 100, thus tightly fixing the steel pipe 100 inside and out.

[0082] This invention, by setting the test chamber 11 of the housing 10 as a sealed structure with an openable opening only on the left side of the test chamber 11, can effectively provide safe protection in the event of a steel pipe 100 bursting during hardness testing. Furthermore, by installing clamping rings 30 on the left side of the test chamber 11 and inside the sealing cover 20, the opening of the test chamber 11 can be opened by the sealing cover 20 without interfering with the entry of the steel pipe 100. Moreover, after the sealing cover 20 seals the opening of the test chamber 11, it can achieve telescopic clamping of the steel pipe 100. During clamping, the contact between the clamping rings 30 and the steel pipe 100 triggers the outer clamping plate 31 to clamp the outer surface of the steel pipe 100 and the inner clamping plate 33 to clamp the inner wall surface of the steel pipe 100, thus clamping the steel pipe 100 from both inside and outside. This prevents the steel pipe 100 from shifting at the moment of contact with the detection head 44, which would affect the accuracy of the test.

[0083] like Figure 3 As shown, the clamping ring 30 on the right side of the test chamber 11 is rotatably connected to the telescopic motor 21, and the clamping ring 30 on the left side of the test chamber 11 is fixedly connected to the rotary motor 12 inside the housing 10.

[0084] During testing, starting the rotary motor 12 drives the steel pipe 100 to rotate, which facilitates the hardness test of the circumference of the steel pipe 100 and obtains more accurate test results.

[0085] like Figure 1 , 2 As shown, a handle 22 is installed on the outer surface of the sealing cover 20. The sealing cover 20 is slidably installed on the left side of the housing 10. The sealing cover 20 opens the opening on the right side of the test chamber 11 by sliding sideways.

[0086] The opposing surfaces of the outer clamping plate 31 and the inner clamping plate 33 are flat or curved surfaces, and rubber strips are installed on these flat or curved surfaces.

[0087] Example 2:

[0088] A hardness testing device, wherein, as Figure 1As shown, it has the steel pipe closed clamping structure of Embodiment 1.

[0089] like Figure 1 , 3 As shown, a hydraulic cylinder 40 is fixedly installed on the housing 10. The hydraulic cylinder 40 is powered by the detection head 44, which is located on the test chamber 11. The hydraulic cylinder 40 pushes the detection head 44 downward so that the detection head 44 presses on the steel pipe 100 to perform a hardness test.

[0090] The telescopic end of the hydraulic cylinder 40 is connected to a guide plate 41. A transmission screw 42 is laterally rotatably connected to the guide plate 41. A connecting block 43 is threaded onto the transmission screw 42. The detection head 44 is installed under the connecting block 43.

[0091] An operation display system 13 is installed on the outside of the housing 10. The operation display system 13 is connected to the telescopic motor 21, the rotary motor 12, the hydraulic cylinder 40, the detection head 44, and the power motor connected to the transmission screw 42 via wired or wireless communication.

[0092] After the steel pipe 100 is securely fixed, the hydraulic cylinder 40 is activated to move the detection head 44 to the surface of the steel pipe 100. Pressure is applied to the steel pipe 100 through the detection head 44 to perform a hardness test. The pressure value is then obtained by the hydraulic cylinder 40 or the detection head 44. The hydraulic cylinder 40 is then activated to reset the detection head 44. Next, the transmission screw 42 is activated to push the connecting block 43 and the detection head 44 to another position on the steel pipe 100. The hardness test of the steel pipe 100 is repeated by moving the detection head 44 down, thereby obtaining multiple sets of pressure values. Finally, these multiple sets of pressure values ​​are transmitted to the operation display system 13. The operation display system 13 converts the pressure values ​​into a curve analysis graph, thereby determining the pressure value of the tested steel pipe 100 and obtaining more accurate test results.

[0093] Example 3:

[0094] A hardness testing device has the same structural features and technical effects as in Embodiment 2, wherein, as Figure 8 As shown, a center adjustment assembly 50 is rotatably mounted in the housing 10, and the center adjustment assembly 50 is located in the test chamber 11.

[0095] The center adjustment assembly 50 has a power shaft 51, the central axis of which is at the same height and intersects with the central axis of the clamping ring 30.

[0096] like Figure 9 As shown, the power shaft 51 is connected to the swing arm 52, and the upper and lower ends of the swing arm 52 are each connected to the guide wheel 53. A guide post 54 is provided between the guide wheels 53. The guide post 54 is a tapered structure that is narrow inside and thick outside.

[0097] like Figure 9 , 10 As shown, there is a space between the upper and lower guide posts 54 for the steel pipe 100 to pass through. After the steel pipe 100 enters the test chamber 11, it will pass through the space between the upper and lower guide posts 54.

[0098] In practice, after the steel pipe 100 is placed into the test chamber 11, due to the different sizes of different steel pipes 100, it is often found that the steel pipe 100 cannot be coaxial with the clamping ring 30. For example, if the ring formed by the outer clamping plate 31 is smaller than the aperture of the test chamber 11, the steel pipe 100 will have difficulty entering the gap between the outer clamping plate 31 and the inner clamping plate 33. Therefore, the ring formed by the outer clamping plate 31 is usually larger than the aperture of the test chamber 11. This requires the clamping ring 30 to be large enough. Similarly, the gap between the outer clamping plate 31 and the inner clamping plate 33 will also be too large. When clamping smaller steel pipes 100, the clamping of the outer wall of the steel pipe 100 is prone to instability, so further improvement is needed.

[0099] Therefore, adjust component 50 through the settings center, such as Figure 11 , 12 As shown, after the steel pipe 100 passes through the upper and lower guide posts 54, the swing arm 52 is rotated by the power shaft 51, causing the lower guide post 54 to lift the steel pipe 100, while the upper guide post 54 presses down on the steel pipe 100. This method can accommodate steel pipes 100 of different sizes. Furthermore, because the upper and lower guide posts 54 rotate around the center of the power shaft 51, and the central axis of the power shaft 51 is at the same height and intersects with the central axis of the clamping ring 30, the steel pipe 100 is coaxial with the clamping ring 30 after being lifted. This facilitates the smooth entry of the steel pipe 100 into the gap between the outer clamping plate 31 and the inner clamping plate 33 during clamping, reducing the size requirements of the clamping ring 30 and making the clamping of the steel pipe 100 by the outer clamping plate 31 more stable.

[0100] Example 4:

[0101] A method for sealing and clamping a steel pipe 100, applied to the pipe sealing and clamping structure of Embodiment 1 or the hardness testing device of Embodiment 2 or 3, includes the following steps:

[0102] When testing the hardness of the steel pipe 100, first push the sealing cover 20 on the side of the box 10 so that the sealing cover 20 moves and opens the opening on the left side of the test chamber 11. Then push the steel pipe 100 into the test chamber 11 through the opening.

[0103] Push the sealing cover 20 back so that the sealing cover 20 re-seals the opening on the left side of the test chamber 11. Then start the telescopic motor 21 in the sealing cover 20 to push the clamping ring 30 inside the sealing cover 20 toward the right end of the steel pipe 100 and push the steel pipe 100 so that the clamping rings 30 on both sides of the test chamber 11 clamp the steel pipe 100.

[0104] During the clamping process, the steel pipe 100 extends into the gap between the outer clamping plate 31 and the inner clamping plate 33 in the clamping ring 30 and comes into contact with the stress plate 36. Under the push of the telescopic motor 21, the stress plate 36, which is pressed against the steel pipe 100, moves towards the telescopic cavity 35 of the clamping ring 30, compressing the pressure spring 39. At the same time, the movement of the stress plate 36 pulls the outer pressure plate 37 to squeeze the outer clamping plate 31 and pulls the inner pressure plate 38 to squeeze the outer clamping plate 31. Under the action of the inclined surface, the outer pressure plate 37 squeezes the outer clamping plate 31 and moves radially inward to clamp the outer surface of the steel pipe 100, while the inner pressure plate 38 squeezes the inner clamping plate 33 and moves radially outward to clamp the inner wall surface of the steel pipe 100, thus tightly fixing the steel pipe 100 inside and out.

[0105] After the steel pipe 100 is tightly fixed, the hydraulic cylinder 40 is activated to push the detection head 44 to the surface of the steel pipe 100. The detection head 44 applies pressure to the steel pipe 100 to perform a hardness test. Then, the hydraulic cylinder 40 or the detection head 44 obtains the pressure value. Then, the hydraulic cylinder 40 is activated to reset the detection head 44. Next, the transmission screw 42 is activated to push the connecting block 43 and the detection head 44 to another position on the steel pipe 100. The hardness test of the steel pipe 100 is repeated by moving the detection head 44 down, thereby obtaining multiple sets of pressure values. Finally, the multiple sets of pressure values ​​are transmitted to the operation display system 13. The operation display system 13 converts the pressure values ​​into a curve analysis graph, thereby knowing the pressure value of the tested steel pipe 100.

[0106] Although the illustrative specific embodiments of the present invention have been described above to enable those skilled in the art to understand the invention, the invention is not limited to the scope of the specific embodiments. For those skilled in the art, all inventions utilizing the concept of the present invention are protected as long as various variations are within the spirit and scope of the invention as defined and determined by the appended claims.

Claims

1. A sealed clamping structure for steel pipes, wherein, include: The housing has a test chamber, and the right side of the test chamber has an opening for a steel pipe to enter. A sealing cover, installed on the left side of the housing, for opening or closing an opening communicating with the test chamber, the sealing cover having: Telescopic motor; Clamping rings are arranged on the left and right sides of the test chamber. The clamping ring on the right side is connected to a telescopic motor and extends and retracts into the sealing cover. The clamping ring is provided with: An outer clamping plate is distributed around the outside of the clamping ring, and the outer clamping plate is slidably connected to the clamping ring by an outer spring; The inner clamping plate is distributed around the inner side of the clamping ring, and there is a gap between the outer clamping plate and the inner clamping plate. The inner clamping plate is slidably connected to the clamping ring by an inner spring. A stress plate, which is slidably connected to the telescopic cavity of the clamping ring, with the outer surface portion of the stress plate located on the gap side, the stress plate having: An outer pressure plate is hooked to an outer clamping plate, and the contact surface between the outer pressure plate and the outer clamping plate is an inclined surface. An inner pressure plate is hooked to an inner clamping plate, and the contact surface between the inner pressure plate and the inner clamping plate is an inclined surface. A pressure spring, which is connected to the stress plate; The housing is rotatably mounted with a center adjustment assembly, which includes two swing arms spaced apart front and rear. The central axis of the power shaft of the center adjustment assembly is at the same height and intersects with the central axis of the clamping ring. The upper and lower ends of the swing arm are each connected to a guide wheel, and a guide post is connected between the guide wheels at corresponding positions on the upper and lower ends of the two swing arms. The guide posts at the upper and lower ends, together with the two swing arms that are spaced apart in front and behind, together form a space for the steel pipe to pass through. After the steel pipe passes through the upper and lower guide columns, the swing arm is driven to rotate by the power shaft, causing the lower guide column to lift the steel pipe and the upper guide column to press down on the steel pipe. Since the upper and lower guide columns rotate around the center of the power shaft, the steel pipe is coaxial with the clamping ring after being lifted.

2. The steel pipe sealed clamping structure according to claim 1, wherein, The clamping ring on the right side of the test chamber is rotatably connected to the telescopic motor, and the clamping ring on the left side of the test chamber is fixedly connected to the rotary motor inside the box.

3. The steel pipe sealed clamping structure according to claim 1, wherein, The sealing cover is slidably installed on the left side of the chamber, and the sealing cover opens the opening on the right side of the test chamber by sliding sideways.

4. The steel pipe sealed clamping structure according to claim 1, wherein, A handle is installed on the outer surface of the sealing cap.

5. The steel pipe sealed clamping structure according to claim 1, wherein, The opposing surfaces of the outer clamping plate and the inner clamping plate are flat or curved surfaces, and rubber strips are installed on the flat or curved surfaces.

6. The steel pipe sealed clamping structure according to claim 1, wherein, The gap between the outer clamping plate and the inner clamping plate is larger than the wall thickness of the steel pipe.

7. A hardness testing device, wherein, The steel pipe has a closed clamping structure as described in any one of claims 1-6.

8. The hardness testing device according to claim 7, wherein, A hydraulic cylinder is fixedly installed on the housing. The hydraulic cylinder is powered by a test head, which is located on the test chamber. The test head is pushed downward by the hydraulic cylinder so that it presses against the steel pipe to perform a hardness test.

9. The hardness testing device according to claim 8, wherein, The telescopic end of the hydraulic cylinder is connected to a guide plate, and a transmission screw is laterally rotatably connected to the guide plate. A connecting block is threaded onto the transmission screw, and the detection head is installed under the connecting block.

10. The hardness testing device according to claim 9, wherein, An operation display system is installed on the outside of the housing. The operation display system is connected to the telescopic motor, rotary motor, hydraulic cylinder, detection head, and power motor connected to the transmission screw via wired or wireless communication.

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