Welded steel pipe flattening test device

Abstract

The invention provides a welded steel pipe flattening test device, and belongs to the technical field of welded pipe test equipment, the welded steel pipe flattening test device comprises a machine table, a rack, a pressing plate and a hydraulic cylinder, one side of the machine table is provided with a supporting plate and a push-out mechanism, the top surface of the supporting plate is flush with the table top of the machine table, the supporting plate is provided with a plurality of clamps for clamping samples, and the clamps are arranged on the rack. The stretching direction of the push-out mechanism is located in the middle of the side face of the machine table. The supporting plate and the electric cylinder are arranged on one side of the machine table, the multiple clamps used for clamping the samples are arranged on the supporting plate, the welded pipe samples are clamped through the clamps, rolling of the welded pipe samples is avoided, the traction mechanism pulls the supporting plate to move horizontally, and the clamps correspond to the telescopic ends of the electric cylinder one by one; the electric cylinder pushes the clamp and the sample on the clamp to the center of the table top of the machine table, automatic feeding of the sample is completed, after the test is completed, the telescopic end of the electric cylinder extends to the second extension length, the sample is pushed away from the table top of the machine table, and discharging of the sample can be more efficient.

Description

Technical Field

[0001] The invention belongs to the technical field of welded pipe testing equipment, and specifically refers to a welded steel pipe flattening testing device. Background Art

[0002] The main purpose of the flattening test of welded steel pipe is to evaluate the deformation performance and compressive strength of the welded pipe and detect possible defects in the weld, such as cracks and lack of fusion, by simulating the deformation process of the welded pipe under lateral pressure. During the test, the weld should be located at 90° and 0° angles to the same force direction, and at least three groups of tests should be conducted to evaluate the weld quality of the welded pipe at two angles. Therefore, during the flattening test, the accuracy of the weld position needs to be maintained to reduce the impact on the test results.

[0003] The current welded steel pipe flattening test device has no automatic feeding mechanism, and the welded pipe usually needs to be placed manually. In order to ensure the accuracy of the weld position, after manually placing the welded pipe and adjusting the weld position, the welded pipe needs to be held continuously to prevent it from rolling. Wait until the pressure plate exerts a certain pressure on the welded pipe and the welded pipe cannot roll before withdrawing your hand. However, there are certain safety hazards when manually placing the welded pipe. Summary of the invention

[0004] In view of the above situation, in order to overcome the defects of the prior art, the present invention provides a welded steel pipe flattening test device, which at least partially solves the above problems.

[0005] The technical solution adopted by the present invention is as follows: The present invention proposes a welded steel pipe flattening test device, comprising: A machine platform, wherein a frame is provided on the top of the machine platform; A pressing plate, slidably connected to the frame, and the pressing plate and the table surface of the machine table are parallel to each other; A hydraulic cylinder, arranged on the top of the frame, for driving the pressing plate to move along the height direction of the frame; A support plate and a push-out mechanism are provided on one side of the machine, the top surface of the support plate is flush with the table surface of the machine, a plurality of clamps for clamping the sample are provided on the support plate, and the extension direction of the push-out mechanism is located in the middle position of the side surface of the machine, and is used to push the clamp to the center of the table surface of the machine and retract it; A traction mechanism is provided below the support plate, which is used to pull the support plate to move horizontally and enable the plurality of clamps to correspond to the telescopic ends of the push-out mechanism one by one.

[0006] Furthermore, the ejection mechanism includes an electric cylinder, the electric cylinder is provided with a first extension length and a second extension length, and the second extension length is greater than the first extension length; When the telescopic end of the electric cylinder is extended to a first extension length, the clamp can be pushed to the center of the table top of the machine, and when the telescopic end of the electric cylinder is extended to a second extension length, the flattened sample can be pushed away from the table top of the machine.

[0007] Furthermore, a push plate is fixed to the telescopic end of the electric cylinder, and two electromagnets are arranged on the push plate, so that the telescopic end of the electric cylinder can be connected to / detached from the clamp through the electromagnets.

[0008] Furthermore, the support plate is provided with a positioning mechanism corresponding to the number of the clamps, the positioning mechanism includes a positioning pin and a positioning seat, the positioning pin is fixed on the clamp, and the positioning seat is fixed on the support plate; When the clamp is located on the support plate, the positioning pin is inserted into the positioning seat, so that the clamp can be pulled and moved by the support plate.

[0009] Furthermore, the clamp includes a driving mechanism and two limiting arms. The driving mechanism is provided with two output ends, which respectively drive the two limiting arms to move away from or towards each other in a horizontal direction, so as to clamp the sample.

[0010] Furthermore, a curved plate is provided on the side of the limit arm facing the clamped sample, and the limit arm and the curved plate are connected by a spring, so that the curved plate has a space that can be elastically collapsed.

[0011] Further, the driving mechanism includes a mounting box, a screw and two transmission blocks, the screw is rotatably connected in the mounting box, the transmission block is connected to the screw, and the screw is provided with two threads in opposite directions, so that when the screw rotates, the two transmission blocks can be driven to move away from or towards each other; A slide slot is provided on one side of the installation box, and one end of the two limit arms passes through the slide slot and is respectively connected to the two transmission blocks.

[0012] Furthermore, one end of the screw rod extends to the outside of the installation box and is fixed with a hand wheel.

[0013] Furthermore, a support rail for supporting the sliding of the support plate is provided on one side of the machine platform.

[0014] Furthermore, a bracket for supporting the electric cylinder is provided on one side of the machine platform.

[0015] The beneficial effects achieved by the present invention using the above structure are as follows: 1. A support plate and a push-out mechanism are arranged on one side of the machine. A plurality of clamps for clamping welded steel pipe samples are arranged on the support plate. The welded pipe samples are clamped by the clamps to prevent the welded pipe samples from rolling. The traction mechanism pulls the support plate to move horizontally and makes the clamps correspond to the telescopic ends of the push-out mechanism one by one. The push-out mechanism pushes the clamps and the samples on the clamps to the center of the table of the machine to complete the automatic feeding of the samples.

[0016] 2. The two limit arms of the fixture are provided with arc plates on the side facing the sample. The limit arms and the arc plates are connected by springs, so that the arc plates have space for elastic collapse. When the pressure plate exerts pressure on the welded pipe sample to deform the welded pipe, the arc plates can collapse inward under pressure, thus avoiding the limit arms being pressed against the table and unable to be withdrawn or deformed and damaged.

[0017] 3. The electric cylinder is provided with a first extension length and a second extension length. When the telescopic end of the electric cylinder is extended to the first extension length, the clamp can be pushed to the center of the table top of the machine to complete the feeding of the sample. After the test is completed, the telescopic end of the electric cylinder is extended to the second extension length, which can push the flattened sample away from the table top of the machine. Manual operation is not required for unloading the sample. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 A structural schematic diagram of a welded steel pipe flattening test device proposed in an embodiment of the present invention; Figure 2 A schematic diagram of feeding and unloading states of a welded steel pipe flattening test device proposed in an embodiment of the present invention; Figure 3 A schematic diagram of a state in which a fixture clamps a welded steel pipe sample in a welded steel pipe flattening test device proposed in an embodiment of the present invention; Figure 4 A schematic diagram of the structure of a fixture in a welded steel pipe flattening test device proposed in an embodiment of the present invention; Figure 5 A schematic diagram of the structure of a driving mechanism in a welded steel pipe flattening test device proposed in an embodiment of the present invention; Figure 6 A schematic diagram of the installation positions of a push plate and an electromagnet in a welded steel pipe flattening test device proposed in an embodiment of the present invention; Figure 7 A schematic diagram of the installation position of the arc plate in a welded steel pipe flattening test device proposed in an embodiment of the present invention; Figure 8 A schematic diagram of a state in which a curved plate is squeezed and stressed in a welded steel pipe flattening test device proposed in an embodiment of the present invention.

[0019] Among them, 1. machine table; 11. frame; 12. pressure plate; 13. hydraulic cylinder; 2. support plate; 21. support rail; 3. traction mechanism; 4. clamp; 41. drive mechanism; 411. installation box; 412. screw rod; 413. transmission block; 414. hand wheel; 42. limit arm; 43. arc plate; 44. spring; 401. slide groove; 5. electric cylinder; 51. bracket; 6. push plate; 7. electromagnet; 8. positioning pin; 9. positioning seat.

[0020] The accompanying drawings are used to provide further understanding of the present invention and constitute a part of the specification. They are used to explain the present invention together with the embodiments of the present invention and do not constitute a limitation of the present invention. DETAILED DESCRIPTION

[0021] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments; based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0022] In the description of the present invention, it should be understood that terms such as “upper”, “lower”, “front”, “back”, “left”, “right”, “top”, “bottom”, “inside” and “outside” indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as limiting the present invention.

[0023] like Figure 1 As shown, the present invention proposes a welded steel pipe flattening test device, which includes a machine platform 1, a frame 11, a pressing plate 12 and a hydraulic cylinder 13.

[0024] The frame 11 includes four guide pillars and a top plate. The four guide pillars are fixed between the top plate and the machine platform 1. The four corners of the pressing plate 12 are respectively provided with guide sleeves corresponding to the guide pillars. The pressing plate 12 is slidably connected to the four guide pillars through the guide sleeves. The hydraulic cylinder 13 is arranged on the top of the frame 11, and the telescopic end of the hydraulic cylinder 13 is connected to the pressing plate 12. The pressing plate 12 is driven to move up and down along the guide pillars by the hydraulic cylinder 13.

[0025] In a specific embodiment, a hydraulic station is provided inside the machine 1, the hydraulic cylinder 13 is connected to the hydraulic station through an oil pipe, and the telescopic movement of the hydraulic cylinder 13 is controlled by a hydraulic control valve on the hydraulic station.

[0026] Furthermore, a pressure sensor is provided between the telescopic end of the hydraulic cylinder 13 and the pressing plate 12 , which can detect the reaction force exerted on the pressing plate 12 in real time.

[0027] Combination Figure 1 and Figure 2 As shown, a support plate 2 and a push-out mechanism are provided on one side of the machine 1. The top surface of the support plate 2 is flush with the table surface of the machine 1. A plurality of clamps 4 for clamping welded steel pipe samples are provided on the support plate 2. The telescopic direction of the push-out mechanism is located in the middle position of the side of the machine 1. The telescopic end of the push-out mechanism is extended to push the clamp 4 on the support plate 2 to the center of the table surface of the machine 1. After the sample feeding is completed, the telescopic end of the push-out mechanism is retracted and the clamp 4 is retracted onto the support plate 2.

[0028] Furthermore, a traction mechanism 3 is provided under the pallet 2, and the pallet 2 is pulled horizontally by the traction mechanism 3 so that multiple clamps 4 on the pallet 2 correspond to the telescopic ends of the pushing mechanism one by one, and the pushing mechanism can push the clamps 4 one by one to the center of the table top of the machine 1 to feed the materials.

[0029] In this way, the welded pipe sample is placed on the support plate 2 in advance, and the position of the weld seam of the welded pipe is manually adjusted, and then the welded pipe sample is clamped by the clamp 4 to prevent the welded pipe sample from rolling. After all the welded pipe samples are clamped, the traction mechanism 3 pulls the support plate 2 to move horizontally, and makes the clamp 4 correspond to the telescopic end of the pushing mechanism one by one. The pushing mechanism pushes the clamp 4 and the sample on the clamp 4 to the center of the table top of the machine table 1, and the pressing plate 12 is pressed down until the pressing plate 12 contacts the sample and generates a certain pressure on the sample to fix the sample. When the pressure sensor detects that the pressure reaches the preset value, the pushing mechanism retracts the clamp 4 to the support plate 2 to complete the automatic feeding of the sample, and the pressing plate 12 continues to press down for testing.

[0030] It should be understood that there is no limit to the number of clamps 4 , and the number of clamps 4 can be set according to production and inspection requirements, and the length of the support plate 2 and the stroke of the traction mechanism 3 can be changed accordingly according to the number of clamps 4 .

[0031] Furthermore, a support rail 21 is provided on one side of the machine 1, and a corresponding slider is provided under the pallet 2. The pallet 2 is slidably connected to the support rail 21 through the slider, and the support rail 21 supports the pallet 2, thereby improving the stability of the pallet 2 when sliding.

[0032] In an optional embodiment, the traction mechanism 3 adopts one of an electric push rod, an electric cylinder, a hydraulic cylinder or an electric screw slide, and preferably an electric screw slide. The electric screw slide has high traction accuracy, so that the clamp 4 can be accurately pulled to the telescopic end of the ejection mechanism to avoid pushing off-center. The slider on the electric screw slide is connected to the support plate 2 through a connecting frame, and the support plate 2 is moved by pulling the slider.

[0033] Combination Figure 2As shown, the pushing mechanism includes an electric cylinder 5, which is provided with a first extension length and a second extension length. When the telescopic end of the electric cylinder 5 is extended to the first extension length, the clamp 4 can be pushed to the center of the table top of the machine 1 to complete the feeding of the sample. After the test is completed, the telescopic end of the electric cylinder 5 is extended to the second extension length, which can push the flattened sample away from the table top of the machine 1, and the unloading of the sample is more efficient.

[0034] In an optional embodiment, a bracket 51 is provided on one side of the machine platform 1 for supporting the electric cylinder 5 .

[0035] Combination Figure 6 As shown, a push plate 6 is fixed to the telescopic end of the electric cylinder 5, and two electromagnets 7 are provided on the push plate 6. When the telescopic end of the electric cylinder 5 extends out to push the clamp 4 to feed the material, the electromagnet 7 is started, and the electromagnet 7 is magnetically connected to the clamp 4. When the electric cylinder 5 retracts the clamp 4 onto the support plate 2, the electromagnet 7 is turned off, and the electromagnet 7 is separated from the clamp 4. After the electromagnet 7 is separated from the clamp 4, the telescopic end of the electric cylinder 5 continues to contract a certain distance to avoid interference and collision between the push plate 6 / electromagnet 7 and the clamp 4 when the support plate 2 moves horizontally to switch the clamp 4.

[0036] In a specific embodiment, the electric screw slide, electric cylinder 5 and electromagnet 7 used in the traction mechanism 3 are all electrically connected to an external control system. The control system controls the actions of the electric screw slide, electric cylinder 5 and electromagnet 7 respectively based on a preset logic. The control system can be implemented based on an industrial computer or an embedded control system.

[0037] Combination Figure 2 , Figure 3 , Figure 4 and Figure 5 As shown, the support plate 2 is provided with a positioning mechanism corresponding to the number of the clamps 4, and the positioning mechanism includes a positioning pin 8 and a positioning seat 9. The positioning pin 8 is fixed on the clamp 4, and the positioning seat 9 is fixed on the support plate 2; When the clamp 4 is retracted onto the support plate 2 , the positioning pin 8 is inserted into the positioning seat 9 to limit the position of the clamp 4 , so that the clamp 4 can be stably pulled and moved by the support plate 2 .

[0038] In an optional embodiment, the end of the locating pin 8 away from the clamp 4 is set to be hemispherical, which can play a guiding role when the locating pin 8 is inserted into the locating seat 9, avoiding the locating pin 8 from being unable to be inserted into the locating seat 9 due to slight deviation.

[0039] Combination Figure 3 and Figure 4As shown, the clamp 4 includes a driving mechanism 41 and two limiting arms 42. The driving mechanism 41 is provided with two output ends, which respectively drive the two limiting arms 42 to move in opposite directions or in opposite directions in the horizontal direction, and the two limiting arms 42 are arranged along the feeding direction. When clamping the welded pipe sample, the welded pipe is placed between the two limiting arms 42, and the axial direction of the welded pipe is parallel to the feeding direction, and then the distance between the two limiting arms 42 is adjusted until the two limiting arms 42 contact with both sides of the welded pipe to limit the welded pipe to prevent the welded pipe from rolling, thereby maintaining the weld position. When the feeding is completed and the clamp 4 is retracted, the two limiting arms 42 are withdrawn along the axial direction of the welded pipe.

[0040] When the limiting arm 42 limits the welding pipe, there is no need to lift the welding pipe, so that the welding pipe is always in contact with the support plate 2. Since the support plate 2 is flush with the table surface of the machine 1, the bottom of the welding pipe can be in contact with the table surface of the machine 1 when pushing the feeding, avoiding the welding pipe from falling and rolling when the clamp 4 is retracted and separated from the welding pipe.

[0041] Furthermore, the bottom of the limiting arm 42 is flush with the table surface of the machine 1 , and when the electric cylinder 5 is extended to the second length, the two limiting arms 42 can push the flattened welded pipe away from the table surface of the machine 1 .

[0042] When feeding, the pressure plate 12 needs to exert a certain pressure on the sample so that the sample is fixed before the clamp 4 can be retracted. However, at this time, the sample will produce a certain deformation. Since the limit arm 42 needs to be close to the sample to limit it during the feeding process, the deformed sample will exert lateral pressure on the limit arm 42, causing the limit arm 42 to be pressed against the table and unable to be withdrawn or deformed and damaged.

[0043] Combination Figure 7 and Figure 8 As shown, a curved plate 43 is provided on the side of the limiting arm 42 facing the clamped sample, and the limiting arm 42 and the curved plate 43 are connected by a spring 44, so that the curved plate 43 has a space that can be elastically collapsed. When clamping the welded pipe sample, the curved plate 43 on the outer side of the limiting arm 42 contacts the welded pipe to limit the welded pipe. Since the spring 44 has a certain elastic supporting force, the position of the welded pipe can be maintained to prevent the welded pipe from rolling, thereby maintaining the position of the weld. When the pressure plate 12 exerts pressure on the welded pipe sample to deform the welded pipe, the arc plate 43 can collapse inward under pressure to prevent the limit arm 42 from being pressed against the table and unable to be withdrawn or deformed and damaged. After the clamp 4 is withdrawn, the arc plate 43 is elastically reset under the action of the spring 44.

[0044] In a specific embodiment, the driving mechanism 41 includes an installation box 411, a screw rod 412 and two transmission blocks 413. The screw rod 412 is rotatably connected in the installation box 411, and the transmission block 413 is connected to the screw rod 412. The screw rod 412 is provided with two threads in opposite directions. When the screw rod 412 rotates, the two transmission blocks 413 are driven to move away from each other or towards each other. A slide groove 401 is opened on one side of the installation box 411, and one end of the two limit arms 42 passes through the slide groove 401 and is respectively connected to the two transmission blocks 413.

[0045] In this way, by rotating the screw rod 412 , the two transmission blocks 413 are driven to move away from or towards each other, and the two transmission blocks 413 drive the two limit arms 42 to move away from or towards each other to clamp the sample.

[0046] Furthermore, one end of the screw rod 412 extends to the outside of the installation box 411 and is fixed with a hand wheel 414, which increases the rotation torque manually with a larger diameter, thereby improving the convenience of rotating the screw rod 412.

[0047] The working principle of the present invention is as follows: the welded pipe sample is placed on the support plate 2 in advance, and the position of the weld seam of the welded pipe is adjusted, and then the welded pipe sample is clamped by the clamp 4 to prevent the welded pipe sample from rolling. After the welded pipe sample is clamped, the traction mechanism 3 pulls the support plate 2 to move horizontally, and makes the clamp 4 correspond to the telescopic end of the electric cylinder 5 one by one. When the telescopic end of the electric cylinder 5 is extended, the electromagnet 7 is started, and the electromagnet 7 is magnetically connected with the clamp 4. The electric cylinder 5 pushes the clamp 4 and the sample on the clamp 4 to the center of the table 1, and the pressing plate 12 is pressed down until the pressing plate 12 contacts the sample and generates a certain pressure on the sample to fix the sample, and then the electric The cylinder 5 retracts the clamp 4 onto the pallet 2, and the pressure plate 12 continues to press down for the test to complete the automatic feeding of the sample. After the test is completed, the telescopic end of the electric cylinder 5 extends to the second extension length, which can push the flattened sample off the table of the machine 1, and the unloading of the sample does not require manual operation by personnel. After the sample is pushed away, the telescopic end of the electric cylinder 5 retracts the clamp 4 onto the pallet 2, and the electromagnet 7 is turned off. At this time, the electromagnet 7 is disengaged from the clamp 4, so that the pallet 2 can pull the clamp 4 to move, and the traction mechanism 3 pulls the pallet 2 to move horizontally, moving the next clamp 4 to the telescopic end of the electric cylinder 5, and then feeding the test again until all the samples are tested.

[0048] In summary of the above embodiments: a support plate 2 and a push-out mechanism are arranged on one side of the machine 1, a plurality of clamps 4 for clamping the sample are arranged on the support plate 2, the welded pipe sample is clamped by the clamp 4 to prevent the welded pipe sample from rolling, the traction mechanism 3 pulls the support plate 2 to move horizontally, and makes the clamps 4 correspond to the telescopic ends of the push-out mechanism one by one, and the push-out mechanism pushes the clamps 4 and the sample on the clamps 4 to the center of the table of the machine 1, thereby completing the automatic feeding of the sample; The two limit arms 42 of the clamp 4 are each provided with an arc plate 43 on the side facing the sample. The limit arms 42 and the arc plate 43 are connected by a spring 44, so that the arc plate 43 has a space that can be elastically collapsed. When the pressure plate 12 exerts pressure on the welded pipe sample to deform the welded pipe, the arc plate 43 can collapse inward under pressure, thereby preventing the limit arms 42 from being pressed against the table and unable to be withdrawn or being deformed and damaged. After the clamp 4 is withdrawn, the arc plate 43 is elastically reset under the action of the spring 44.

[0049] The pushing mechanism includes an electric cylinder 5, which is provided with a first extension length and a second extension length. When the telescopic end of the electric cylinder 5 is extended to the first extension length, the clamp 4 can be pushed to the center of the table top of the machine 1 to complete the feeding of the sample. After the test is completed, the telescopic end of the electric cylinder 5 is extended to the second extension length, which can push the flattened sample away from the table top of the machine 1. The unloading of the sample does not require manual operation by personnel.

[0050] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0051] The present invention and its embodiments are described above, and such description is not restrictive. The drawings show only one embodiment of the present invention, and the actual structure is not limited thereto. In short, if ordinary technicians in the field are inspired by it, without departing from the purpose of the invention, they can design a structure and embodiment similar to the technical solution without creativity, which should belong to the protection scope of the present invention.

Claims

1. A welded steel pipe flattening test device, characterized in that: include: A machine platform (1), wherein a frame (11) is provided on the top of the machine platform (1); A pressing plate (12) is slidably connected to the frame (11), and the pressing plate (12) and the table surface of the machine table (1) are parallel to each other; A hydraulic cylinder (13) is arranged on the top of the frame (11) and is used to drive the pressing plate (12) to move along the height direction of the frame (11); A support plate (2) and a push-out mechanism are provided on one side of the machine platform (1); the top surface of the support plate (2) is flush with the table surface of the machine platform (1); a plurality of clamps (4) for clamping welded steel pipe specimens are provided on the support plate (2); the push-out mechanism has a telescopic direction located at the middle position of the side surface of the machine platform (1) and is used to push the clamps (4) to the center of the table surface of the machine platform (1) and retract them; A traction mechanism (3) is provided below the support plate (2) for traction of the support plate (2) to move horizontally and enable the plurality of clamps (4) to correspond one by one to the telescopic ends of the push-out mechanism.

2. The welded steel pipe flattening test device according to claim 1, characterized in that: The ejection mechanism comprises an electric cylinder (5), the electric cylinder (5) being provided with a first extension length and a second extension length, and the second extension length being greater than the first extension length; When the telescopic end of the electric cylinder (5) is extended to a first extension length, the clamp (4) can be pushed to the center of the table top of the machine table (1); when the telescopic end of the electric cylinder (5) is extended to a second extension length, the flattened welded steel pipe sample can be pushed away from the table top of the machine table (1).

3. The welded steel pipe flattening test device according to claim 2, characterized in that: A push plate (6) is fixed to the telescopic end of the electric cylinder (5), and two electromagnets (7) are provided on the push plate (6), so that the telescopic end of the electric cylinder (5) can be connected to / disconnected from the clamp (4) through the electromagnets (7).

4. The welded steel pipe flattening test device according to claim 1, characterized in that: The support plate (2) is provided with positioning mechanisms corresponding to the number of the clamps (4), the positioning mechanisms comprising positioning pins (8) and positioning seats (9), the positioning pins (8) being fixed on the clamps (4), and the positioning seats (9) being fixed on the support plate (2); When the clamp (4) is located on the support plate (2), the positioning pin (8) is inserted into the positioning seat (9), so that the clamp (4) can be pulled and moved by the support plate (2).

5. The welded steel pipe flattening test device according to claim 4, characterized in that: The clamp (4) comprises a driving mechanism (41) and two limiting arms (42), wherein the driving mechanism (41) is provided with two output ends, which respectively drive the two limiting arms (42) to move in opposite directions or towards each other in a horizontal direction, so as to clamp the welded steel pipe sample.

6. The welded steel pipe flattening test device according to claim 5, characterized in that: The limiting arm (42) is provided with an arc-shaped plate (43) on the side facing the welded steel pipe sample clamping side, and the limiting arm (42) and the arc-shaped plate (43) are connected via a spring (44), so that the arc-shaped plate (43) has a space capable of elastic collapse.

7. The welded steel pipe flattening test device according to claim 5, characterized in that: The driving mechanism (41) comprises a mounting box (411), a screw rod (412) and two transmission blocks (413); the screw rod (412) is rotatably connected in the mounting box (411); the transmission block (413) is connected to the screw rod (412); the screw rod (412) is provided with two threads in opposite directions, so that when the screw rod (412) rotates, it can drive the two transmission blocks (413) to move away from or towards each other; A slide groove (401) is provided on one side of the installation box (411), and one end of the two limit arms (42) passes through the slide groove (401) and is respectively connected to the two transmission blocks (413).

8. The welded steel pipe flattening test device according to claim 7, characterized in that: One end of the screw rod (412) extends to the outside of the installation box (411) and is fixed with a hand wheel (414).

9. The welded steel pipe flattening test device according to claim 1, characterized in that: A support guide rail (21) for supporting the sliding of the support plate (2) is provided on one side of the machine platform (1).

10. The welded steel pipe flattening test device according to claim 2, characterized in that: A bracket (51) for supporting the electric cylinder (5) is provided on one side of the machine platform (1).

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