A clip device, fatigue testing machine

Abstract

The application discloses a kind of clamp device and fatigue testing machine, applied to workpiece fatigue detection technical field, clamp device includes: clamping tool;Guide rod assembly, including beam fixed component, guide rod body and column guide assembly, guide rod body is swingably set on beam fixed component, column guide assembly can slide relative to column, guide rod body can be fixed on column guide assembly;Limit wheel assembly, including limit connecting plate, limit wheel frame and limit wheel body, the horizontal position of limit connecting plate is adjustable, limit wheel frame is hinged with limit connecting plate, limit wheel body is rotatably installed in limit wheel frame, and limit wheel frame is equipped with the limit space for guide rod body placement, limit wheel body is attached with guide rod body and is slidably connected.The clamp device provided by the application eliminates the radial force of actuator and workpiece sample, and the workpiece sample will not rotate when clamped under the clamping of clamping tool when vibrating at a certain frequency.

Description

Technical Field

[0001] This invention relates to the field of workpiece fatigue testing technology, and in particular to a fixture device and a fatigue testing machine. Background Technology

[0002] When conducting fatigue tests on workpiece samples, a fatigue testing machine is generally required. For large-tonnage testing machines, since the force applied to the workpiece is relatively large, a frame with a larger load-bearing capacity should be provided. A common frame is a four-column frame, with the bottom of the four columns fixed inside the base of the frame and the top fixed in the crossbeam of the frame.

[0003] However, due to the large size of the workpiece specimens to be tested, there is a deviation between the installation position of the workpiece specimen and the direction of the tensile axis during installation. If a single fixture is used to directly connect to the actuator, the actuator will be subjected to radial force due to the installation deviation, which will greatly reduce the service life of the actuator. At the same time, if the fixture does not restrict the rotation of the workpiece specimen around the actuator loading axis, the bolt connection of the workpiece specimen will loosen after repeated reciprocating tensile tests, causing the displacement set by the tensile test to deviate, ultimately affecting the accuracy of the test data.

[0004] Therefore, how to improve the reliability of the clamping device is a technical problem that needs to be solved by those skilled in the art. Summary of the Invention

[0005] The purpose of this invention is to provide a clamping device and a fatigue testing machine that can reduce the radial force of the actuator and improve the service life of the actuator.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A clamping device is used on a fatigue testing machine, the fatigue testing machine including an actuator, a crossbeam, a column, and a base, comprising:

[0008] A clamping fixture is used to clamp a workpiece sample. The clamping fixture is connected between the actuator and the base so that the actuator can stretch the workpiece sample.

[0009] A guide rod assembly includes a crossbeam fixing component, a guide rod body, and a column guide assembly. The crossbeam fixing component is disposed on the crossbeam. The guide rod body is swayably disposed on the crossbeam fixing component. The column guide assembly is installed on the column and can slide relative to the column. When the angle of the guide rod body is determined, the guide rod body can be fixed on the column guide assembly.

[0010] The limiting wheel assembly includes a limiting connecting plate, a limiting wheel frame, and a limiting wheel body. The limiting connecting plate is connected to the clamping fixture, and the horizontal position of the limiting connecting plate is adjustable. The limiting wheel frame is hinged to the limiting connecting plate, and the limiting wheel body is rotatably mounted on the limiting wheel frame. The limiting wheel frame has a limiting space for the guide rod body to be inserted. The limiting wheel body and the guide rod body are in contact and slidably connected.

[0011] On the other hand, the guide rod assembly also includes a guide rod fixing plate and a guide shaft. The guide shaft is connected between the crossbeam fixing component and the guide rod body, and the guide rod body can swing radially relative to the actuator. The guide rod fixing plate is fixedly connected to the guide rod body and is detachably fixed to the column guide assembly.

[0012] On the other hand, the column guide assembly includes a guide connecting plate, a guide base plate, and a spring connecting assembly. The guide rod body can be fixed on the guide base plate. The guide connecting plate is installed on the guide base plate, the spring connecting assembly is installed on the guide connecting plate, the column is located between the spring connecting assembly and the guide base plate, and the spring connecting assembly can press the surface of the column.

[0013] On the other hand, the spring connecting assembly includes a spring base plate, a spring clamping pad, a spring component, and a spring force adjustment assembly. The spring base plate is connected to the guide connecting plate. The spring clamping pad has a clamping surface for cooperating with the column. The spring base plate is located on the side of the spring clamping pad away from the clamping surface. The spring component is disposed between the spring base plate and the spring clamping pad. The spring force adjustment assembly passes through the spring base plate and the spring clamping pad, and the spring force adjustment assembly changes the spring force of the spring component by adjusting the distance between the spring base plate and the spring clamping pad.

[0014] On the other hand, the elastic adjustment assembly includes a guide sleeve and a fastener. The spring base plate and the spring compression pad are provided with a groove on the side close to each other for the spring component to be inserted. There is a gap between the spring base plate and the spring compression pad. The spring compression pad is provided with a first step on the side close to the compression surface. The guide sleeve is engaged with the first step. The spring base plate is provided with a second step on the side away from the spring compression pad. The fastener is engaged with the second step. The guide sleeve and the fastener are connected by a threaded connection to adjust the width of the gap.

[0015] Furthermore, after the spring connecting assembly is fitted with the column, the fastener is loosened to reset the spring component and press the spring clamping pad onto the column.

[0016] On the other hand, the clamping fixture includes, from top to bottom, an upper fixed plate, an upper platform plate, a clamping connecting plate, a clamping connecting base plate, a lower platform plate, and a lower fixed plate. The clamping connecting plate extends vertically and is detachably connected between the upper platform plate and the clamping connecting base plate. The top of the upper fixed plate is connected to the actuator, the bottom of the upper fixed plate is hinged to the upper platform plate, and the lower platform plate is hinged to the lower fixed plate. The workpiece sample is clamped between the clamping connecting base plate and the lower platform plate. And / or, it also includes an anti-rotation component, which is disposed on the upper fixed plate and is used to engage with the crossbeam to restrict the upper fixed plate from rotating circumferentially along the actuator.

[0017] On the other hand, the clamping connecting plate is an I-shaped plate. The bottom of the upper platform and the top of the connecting base plate are respectively provided with a plurality of sliding grooves for the clamping connecting plate to slide into and engage vertically. The width of the connecting base plate is smaller than the width of the upper platform, and the width of the clamping connecting plate is the same as the width of the connecting base plate. A clamping top block is also provided in the sliding groove of the upper platform. The clamping fixture also includes a plurality of clamping baffles. The clamping baffles are disposed at the ends of the sliding grooves to block the clamping connecting plate or the clamping top block.

[0018] On the other hand, the limiting wheel body includes a first limiting wheel body and a second limiting wheel body, which are arranged along the extension direction of the guide rod body. The circumferential surfaces of the first limiting wheel body and the second limiting wheel body are provided with a rolling structure that matches the outer circumferential shape of the guide rod body. The limiting wheel assembly also includes a limiting hinge shaft, which is connected between the limiting connecting plate and the limiting wheel frame. The limiting hinge shaft extends in the horizontal direction, and the limiting wheel frame can swing in the vertical direction so that both the first limiting wheel body and the second limiting wheel body are in contact with the guide rod body.

[0019] On the other hand, the limiting wheel assembly also includes a limiting rolling shaft and a self-aligning ball bearing. The limiting wheel body is mounted on the limiting rolling shaft, and the limiting rolling shaft is mounted on the limiting wheel frame via the self-aligning ball bearing. The self-aligning ball bearing is used to finely adjust the angle of the limiting rolling shaft so that the limiting wheel body fits against the guide rod body.

[0020] The present invention also provides a fatigue testing machine, including the clamping device described in any one of the above claims.

[0021] The clamping device provided by this invention, through the setting of the clamping fixture, can effectively clamp and fix the workpiece sample. During fatigue testing, the actuator, driven by the drive mechanism, stretches the workpiece to ensure the smooth progress of the test. Through the setting of the guide rod assembly, the guide rod assembly is installed on the crossbeam, and the guide rod body in the guide rod assembly can swing relative to the crossbeam during installation. After the guide rod body swings to a suitable angle, it is fixed. The guide rod body can effectively limit the movement of the limiting wheel assembly. Furthermore, through the setting of the column guide assembly, the column guide assembly is set on the column, and the column guide assembly can slide relative to the column. The column guide assembly serves to fix the guide rod body. Simultaneously, by fine-tuning its position on the column, the column guide assembly can adapt to changes in the actuator's position during the test. The limiting wheel assembly, mounted on the clamping fixture, moves vertically with it. In cooperation with the column guide assembly, the limiting wheel assembly restricts the longitudinal movement of the limiting wheel assembly, preventing rotation of the clamping fixture and thus counteracting the radial force on the actuator. Furthermore, the force on the limiting wheel assembly is transmitted through the guide rod body to the column guide assembly, and then to the column, further reducing the radial force on the actuator.

[0022] In one embodiment, the limiting wheel body includes a first limiting wheel body and a second limiting wheel body, which are arranged along the extending direction of the guide rod body. The circumferential surfaces of the first and second limiting wheel bodies are provided with a rolling structure adapted to the outer circumferential shape of the guide rod body. The limiting wheel assembly further includes a limiting hinge shaft, which is connected between the limiting connecting plate and the limiting wheel frame. The limiting hinge shaft extends in a horizontal direction, and the limiting wheel frame can swing in a vertical direction so that both the first and second limiting wheel bodies are in contact with the guide rod body. The above configuration, through the setting of the first limiting wheel body and the second limiting wheel body, utilizes the hinged cooperation between the limiting connecting plate and the limiting wheel frame. When the fixture assembly undergoes slight torsion, the position of the limiting wheel frame will be adjusted accordingly, so that the first limiting wheel body and the second limiting wheel body always fit against the guide rod body, thereby adapting to the positional deviation caused by the misalignment of the workpiece sample and the actuator axis during the test.

[0023] The fatigue testing machine provided by the present invention is equipped with the above-mentioned clamping device. Since the clamping device has the above-mentioned technical effects, the fatigue testing machine equipped with the clamping device should also have the corresponding technical effects. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention or related technologies, the drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 A front view of a specific embodiment of the clamping device provided by the present invention;

[0026] Figure 2-1 for Figure 1 The DD cross-sectional view of the fixture device shown;

[0027] Figure 2-2 for Figure 2-1 A magnified view of a portion of the image;

[0028] Figure 3 A side view of a specific embodiment of the clamping device provided by the present invention;

[0029] Figure 4-1 A top view of a specific embodiment of the clamping device provided by the present invention;

[0030] Figure 4-2 for Figure 4-1 A magnified view of a portion of the image;

[0031] Figure 5-1 This is a partial perspective view of the clamping device provided by the present invention;

[0032] Figure 5-2 for Figure 5-1 A magnified view of a portion of the image;

[0033] Figure 6 for Figure 2-1 An enlarged structural schematic diagram of part I in the fixture device shown;

[0034] Figure 7 This is an enlarged structural schematic diagram of the column guide assembly in the clamping device provided by the present invention;

[0035] Figure 8 This is an enlarged structural schematic diagram of the limiting wheel assembly in the clamping device provided by the present invention;

[0036] Figure 9This is a schematic diagram showing the positional relationship between the limiting wheel assembly and the column guide assembly in the clamping device provided by the present invention.

[0037] Figure 10 This is a schematic diagram of the clamping connecting plate, clamping baffle, and clamping pad in the clamping device provided by the present invention;

[0038] Figure 11 This is an exploded view of the clamping fixture in the clamping device provided by the present invention.

[0039] Figure label:

[0040] A-Crossbeam; B-Fixing fixture; C-Column; D-Base;

[0041] 1-Actuator; 2-Locking pad; 3-Clamping flange; 4-Guide rod assembly; 41-Crossbeam fixing component; 42-Guide shaft; 43-Guide rod fixing plate; 44-Guide rod body; 45-Guide base plate; 46-Guide connecting plate; 47-Spring base plate; 48-Spring clamping pad; 49-Spring component; 50-1-Guide sleeve; 50-2-Fastener; 5-Limit wheel assembly; 51-Limit connecting plate; 51-1-Horizontal adjustment hole; 52-Limit hinge shaft; 53-Limit wheel frame; 54-Bearing end cover; 55-Oil seal; 5 6-First oil seal positioning sleeve; 57-Limiting roller shaft; 58-Self-aligning ball bearing; 59-Second oil seal positioning sleeve; 60-Limiting wheel body; 6-Anti-rotation component; 7-Upper fixing plate; 8-Upper hinge shaft; 9-Clamping bushing; 10-Upper platform plate; 11-Clamping connecting plate; 11-1-Clamping baffle; 11-2-Clamping top block; 12-Clamping connecting base plate; 13-Upper adjusting shim; 14-Lower adjusting shim; 15-Workpiece sample; 16-Workpiece lower connecting side plate; 17-Lower platform plate; 18-Lower fixing plate; 19-Lower hinge shaft; 20-Joint bearing. Detailed Implementation

[0042] The core of this invention is to provide a clamping device and a fatigue testing machine that can significantly reduce the radial force borne by the actuator, thereby improving the accuracy of the test results.

[0043] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on 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.

[0044] Terminology Explanation:

[0045] Four-column fatigue testing machine: an experimental device used to measure the mechanical properties of a certain type of material. During operation, it performs reciprocating tensile tests on some workpiece samples at a certain frequency. The workpiece samples are placed vertically in the center of the testing machine and fixedly connected to the clamping fixtures of the fatigue testing machine. The crossbeam and base of the fatigue testing machine are connected by four columns. At the same time, the crossbeam can be moved up and down the four columns to a designated position and locked according to the length of the workpiece sample.

[0046] Actuator: A mechanical component that is hydraulically driven and controlled to perform linear reciprocating motion according to a certain cycle.

[0047] Spherical plain bearing: a type of spherical sliding bearing, mainly composed of an inner ring with an outer spherical surface and an outer ring with an inner spherical surface; this structure allows the spherical plain bearing to tilt at any angle and still work normally even when the support shaft and the housing bore are not significantly concentric.

[0048] Please refer to Figures 1 to 11 , Figure 1 A front view of a specific embodiment of the clamping device provided by the present invention; Figure 2-1 for Figure 1 The DD cross-sectional view of the fixture device shown; Figure 2-2 for Figure 2-1 A magnified view of a portion of the image; Figure 3 A side view of a specific embodiment of the clamping device provided by the present invention; Figure 4-1 A top view of a specific embodiment of the clamping device provided by the present invention; Figure 4-2 for Figure 4-1 A magnified view of a portion of the image; Figure 5-1 This is a partial perspective view of the clamping device provided by the present invention; Figure 5-2 for Figure 5-1 A magnified view of a portion of the image; Figure 6 for Figure 2-1 An enlarged structural schematic diagram of part I in the fixture device shown; Figure 7 This is an enlarged structural schematic diagram of the column guide assembly in the clamping device provided by the present invention; Figure 8 This is an enlarged structural schematic diagram of the limiting wheel assembly in the clamping device provided by the present invention; Figure 9 This is a schematic diagram showing the positional relationship between the limiting wheel assembly and the column guide assembly in the clamping device provided by the present invention. Figure 10 This is a schematic diagram of the clamping connecting plate, clamping baffle, and clamping pad in the clamping device provided by the present invention; Figure 11 This is an exploded view of the clamping fixture in the clamping device provided by the present invention.

[0049] In this embodiment, the clamping device is used on the fatigue testing machine, which includes an actuator 1, a crossbeam A, a column C, and a base D. The fatigue testing machine can be a four-column fatigue testing machine. The crossbeam A and the base D are located at the top and bottom of the fatigue testing machine, respectively. The connecting column of the actuator 1 is connected to the drive mechanism. The drive mechanism can be a hydraulic cylinder, and the piston rod of the hydraulic cylinder is connected to the connecting column of the actuator 1.

[0050] The clamping device includes:

[0051] A clamping fixture is used to clamp the workpiece sample 15. The clamping fixture is connected between the actuator 1 and the base D so that the actuator 1 can stretch the workpiece sample 15.

[0052] The guide rod assembly 4 is used to connect with the crossbeam A. The guide rod assembly 4 includes a crossbeam fixing component 41, a guide rod body 44, and a column guide assembly. The crossbeam fixing component 41 is disposed on the crossbeam A. The guide rod body 44 is swayably disposed on the crossbeam fixing component 41. The column guide assembly is installed on the column C. The column guide assembly can slide relative to the column C. When the angle of the guide rod body 44 is determined, the guide rod body 44 can be fixed on the column guide assembly.

[0053] The limiting wheel assembly 5 includes a limiting connecting plate 51, a limiting wheel frame 53, and a limiting wheel body 60. The limiting connecting plate 51 is connected to the clamping fixture, and its horizontal position is adjustable. The limiting wheel frame 53 is hinged to the limiting connecting plate 51. The limiting wheel body 60 is rotatably mounted on the limiting wheel frame 53, and the limiting wheel frame 53 has a limiting space for the guide rod body 44 to be inserted. The limiting wheel body 60 and the guide rod body 44 are in contact and slidably connected. To ensure the positional stability between the limiting connecting plate 51 and the clamping fixture, the limiting connecting plate 51 can be a Y-shaped structure, such as... Figure 9 As shown, one side of the limiting connecting plate 51 has a double-layer structure, located on the upper and lower sides of the upper fixed plate 7 of the clamping fixture, that is, the limiting connecting plate 51 can clamp the upper fixed plate 7 to ensure the horizontal state of the limiting connecting plate 51.

[0054] Specifically, the column C extends vertically, and the guide rod body 44 extends vertically. During installation, the position of the column guide assembly in the guide rod assembly 4 on the column C can be adjusted as needed. Once the position of the guide rod assembly 4 is determined, it can remain stationary. Only when subjected to a large external force will the guide rod assembly 4 slide relative to the column C. The limiting connecting plate 51 extends horizontally, and its horizontal position is adjustable. Since the clamping fixture and the limiting wheel body 60 are located on both sides of the limiting connecting plate 51, and the limiting wheel body 60 needs to fit against the guide rod body 44, the horizontal position of the limiting connecting plate 51 is adjustable to accommodate the gap between the clamping fixture and the guide rod body 44, thus meeting assembly requirements.

[0055] The clamping device provided by this invention, through the setting of the clamping fixture, can effectively clamp and fix the workpiece sample 15. During fatigue testing, the actuator 1, driven by the drive mechanism, stretches the workpiece to ensure the smooth progress of the test. Through the setting of the guide rod assembly 4, the guide rod assembly 4 is installed on the crossbeam A, and the guide rod body 44 in the guide rod assembly 4 can swing relative to the crossbeam A during the installation process. After the guide rod body 44 swings to a suitable angle, the guide rod body 44 is fixed. The guide rod body 44 can effectively limit the position of the limiting wheel assembly 5. Furthermore, through the setting of the column guide assembly, the column guide assembly is set on the column C, and the column guide assembly can swing relative to the column C. When column C slides, the column guide assembly serves to fix the guide rod body 44. At the same time, the column guide assembly can adapt to the position changes of actuator 1 during the test by finely adjusting its position on column C. With the setting of the limit wheel assembly 5, which is installed on the clamping fixture, it can move vertically with the clamping fixture. The limit wheel assembly 5 restricts the longitudinal movement direction of the limit wheel assembly 5 by cooperating with the column guide assembly, preventing the clamping fixture from rotating, thereby offsetting the radial force on actuator 1. At the same time, the force on the limit wheel assembly 5 is transmitted to the column guide assembly through the guide rod body 44, and then to column C, thereby further reducing the radial force on actuator 1.

[0056] In some embodiments, the limiting connecting plate 51 is provided with a horizontal adjustment hole 51-1. The upper fixing plate 7 of the clamping fixture passes through the horizontal adjustment hole 51-1 and the limiting connecting plate 51 is installed on the clamping fixture. The horizontal position of the limiting connecting plate 51 can be adjusted through the horizontal adjustment hole 51-1. Furthermore, there can be four limiting wheel assemblies 5, which are evenly installed at the four corners of the upper fixing plate 7. The installation position of each limiting wheel assembly 5 can be adjusted independently, and the limiting wheel assembly 5 can withstand lateral force.

[0057] In some embodiments, the guide rod assembly 4 further includes a guide rod fixing plate 43 and a guide shaft 42. The guide shaft 42 is connected between the crossbeam fixing component 41 and the guide rod body 44, and the guide rod body 44 can swing radially relative to the actuator 1. The guide rod fixing plate 43 is fixedly connected to the guide rod body 44 and is detachably fixed on the column guide assembly. The axial direction of the guide shaft 42 should be perpendicular to the axial direction of the actuator 1, and the installation position of the guide shaft 42 should be such that the rotation plane of the guide rod body 44 can cover the axis of the actuator 1. That is, during the installation of the guide rod body 44, the guide rod body 44 can swing toward the axis of the actuator 1. After the position of the guide rod body 44 is determined, that is, after the guide rod body 44 can smoothly cooperate with the limit wheel assembly 5, the guide rod body 44 is locked to meet the assembly deviation.

[0058] In some embodiments, the column guide assembly includes a guide connecting plate 46, a guide base plate 45, and a spring connecting assembly. The guide rod body 44 can be fixed on the guide base plate 45. Specifically, the guide rod body 44 is fixed on the guide base plate 45 by a guide rod fixing plate 43. The guide connecting plate 46 is installed on the guide base plate 45, and the spring connecting assembly is installed on the guide connecting plate 46. The column C is located between the spring connecting assembly and the guide base plate 45, and the spring connecting assembly can press against the surface of the column C to prevent the column guide assembly from slipping along the column C. Furthermore, the spring connecting assembly creates an elastic clamping force between the spring connecting assembly and the column C, which keeps the spring connecting assembly on the column C. Only when the spring connecting assembly is subjected to a large force will it move relative to the extension direction of the column C. The crossbeam fixing component 41 on the guide base plate 45 is a flexible connection to reduce vibration and impact.

[0059] In some embodiments, the spring connecting assembly includes a spring base plate 47, a spring clamping pad 48, a spring component 49, and a spring force adjustment assembly. The spring base plate 47 is connected to the guide connecting plate 46. The spring clamping pad 48 has a clamping surface for engaging with the column C. The clamping surface can be an arc-shaped surface adapted to the surface shape of the column C. The spring base plate 47 is located on the side of the spring clamping pad 48 away from the clamping surface. The spring component 49 is disposed between the spring base plate 47 and the spring clamping pad 48. The spring force adjustment assembly passes through the spring base plate 47 and the spring clamping pad 48. 8. The elastic force adjustment component changes the elastic force of the spring component 49 by adjusting the distance between the spring base plate 47 and the spring clamping pad 48. That is, the spring base plate 47 and the spring clamping pad 48 clamp the spring component 49. The closer the distance between the spring base plate 47 and the spring clamping pad 48, the greater the elastic force of the spring component 49. Specifically, the spring component 49 is preferably a disc spring, which has a large elastic force and is easy to obtain. The spring base plate 47 is installed on the crossbeam A, and the guide connecting plate 46 is installed on the spring base plate 47. When the crossbeam A moves, it can pull the spring connecting component to move relative to the column C.

[0060] In some embodiments, the elastic adjustment assembly includes a guide sleeve 50-1 and a fastener 50-2. A groove for inserting the spring component 49 is provided on the side of the spring base plate 47 and the spring pressure pad 48 that are close to each other. A gap exists between the spring base plate 47 and the spring pressure pad 48. A first step is provided on the side of the spring pressure pad 48 near the pressing surface, and the guide sleeve 50-1 engages with the first step. A second step is provided on the side of the spring base plate 47 away from the spring pressure pad 48, and the fastener 50-2 engages with the second step. The guide sleeve 50-1 and the fastener 50-2 are connected by a threaded connection to adjust the width of the gap. Furthermore, after the spring connecting assembly is fitted with the column C, the fastener can be loosened and tightened. The fastener 50-2 resets the spring component 49 and presses the spring compression pad 48 onto the column C. Specifically, the fastener 50-2 can be a screw. During installation, the fastener 50-2 can be tightened to bring the fastener 50-2 and the guide sleeve 50-1 closer together, thereby reducing the gap between the spring base plate 47 and the spring compression pad 48 and pressing the spring component 49. This determines the initial compression of the spring component 49. After the spring connecting assembly is fitted to the column C, the fastener 50-2 is loosened, releasing the elastic force of the spring component 49 and pressing the spring compression pad 48 onto the column C, preventing the spring compression pad 48 from sliding along the axial direction of the column C.

[0061] In some embodiments, the clamping fixture includes, from top to bottom, an upper fixed plate 7, an upper platform plate 10, a clamping connecting plate 11, a clamping connecting base plate 12, a lower platform plate 17, and a lower fixed plate 18. The clamping connecting plate 11 extends vertically and is detachably connected between the upper platform plate 10 and the clamping connecting base plate 12. The top of the upper fixed plate 7 is connected to the actuator 1, and the bottom of the upper fixed plate 7 is hinged to the upper platform plate 10. The lower platform plate 17 is hinged to the lower fixed plate 18. The workpiece sample 15 is clamped between the clamping connecting base plate 12 and the lower platform plate 17. Specifically, the clamping connecting plate 11 can... The fixture is designed in an I-shape, with T-slots on the upper plate 10 and the clamping connecting base plate 12 for axial positioning with the clamping connecting plate 11. An upper hinge shaft 8 is provided between the bottom of the upper fixed plate 7 and the upper plate 10, and a lower hinge shaft 19 is provided between the lower plate 17 and the lower fixed plate 18. Spherical bearings 20 are also provided between the bottom of the upper fixed plate 7 and the upper plate 10, and between the lower plate 17 and the lower fixed plate 18, enabling 360° rotation between the upper fixed plate 7 and the upper plate 10, and between the lower plate 17 and the lower fixed plate 18, thus preventing interference caused by axial misalignment of the workpiece. Both the upper plate 10 and the lower plate 17 can be single U-shaped or T-shaped plates, i.e., the main view shows a T-shaped structure, while the connection part is a U-shaped structure, passing through the upper hinge shaft 8 or the lower hinge shaft 19. The upper plate 10 is inserted upwards into the upper fixed plate 7 for connection, shortening the overall height of the clamping fixture.

[0062] In some embodiments, an anti-rotation component 6 is also included. The anti-rotation component 6 is disposed on the upper fixed plate 7 and is used to engage with the crossbeam A to restrict the upper fixed plate 7 from rotating circumferentially along the actuator 1. Specifically, once the position of the upper fixed plate 7 and other structures in the clamping fixture is determined, the anti-rotation component 6 can be directly inserted upward into the crossbeam A to lock the axial angle position of the upper fixed plate 7 and its fixedly connected components so that it no longer changes.

[0063] In some embodiments, the clamping connecting plate 11 is an I-shaped plate. The bottom of the upper platform 10 and the top of the clamping connecting base plate 12 are respectively provided with several grooves for the clamping connecting plate 11 to slide into and engage vertically. The width of the clamping connecting base plate 12 is smaller than the width of the upper platform 10. Both the clamping connecting base plate 12 and the upper platform 10 can be square structures arranged horizontally. The width direction of the clamping connecting base plate 12 is parallel to the horizontal extension direction of the clamping connecting plate 11. Of course, the length of the clamping connecting base plate 12 can also be smaller than the length of the upper platform 10. By designing the size of the clamping connecting base plate 12 to be smaller than that of the upper platform 10, costs can be reduced and the weight of the clamping fixture can be decreased. The width of the clamping connecting plate 11 is the same as the width of the connecting base plate. Since the width of the clamping connecting base plate 12 is smaller than the width of the upper platform plate 10, the width of the clamping connecting plate 11 will be smaller than the width of the upper platform plate 10. In order to prevent the clamping connecting plate 11 from sliding in the groove of the upper platform plate 10, a clamping top block 11-2 is also provided in the groove of the upper platform plate 10. The clamping fixture also includes several clamping baffles 11-1. The clamping baffles 11-1 are set at the end of the groove to block the clamping connecting plate 11 or the clamping top block 11-2. That is, the clamping baffles 11-1 at the clamping connecting base plate 12 abut against the clamping connecting plate 11, and the clamping baffles 11-1 at the upper platform plate 10 abut against the clamping top block 11-2. In other words, the clamping connecting plate 11 is connected to the upper platform plate 10 via a T-shaped slide groove, and four top blocks are provided on both sides of the clamping connecting plate 11 to prevent the clamping connecting plate 11 from moving within the T-shaped slide groove of the upper platform plate 10.

[0064] In some embodiments, the limiting wheel body 60 can be a U-shaped roller, that is, the position where the limiting wheel body 60 and the guide rod body 44 cooperate is U-shaped; the limiting wheel assembly 5 can be a double U-shaped roller assembly. Specifically, the limiting wheel body 60 includes a first limiting wheel body 60 and a second limiting wheel body 60, which are arranged along the extension direction of the guide rod body 44. The circumferential surfaces of the first limiting wheel body 60 and the second limiting wheel body 60 are provided with a rolling structure that matches the outer circumferential shape of the guide rod body 44; the limiting wheel assembly 5 also includes a limiting hinge shaft 52, which is connected between the limiting connecting plate 51 and the limiting wheel frame 53. The limiting hinge shaft 52 extends in the horizontal direction, and the limiting wheel frame 53 can swing in the vertical direction so that both the first limiting wheel body 60 and the second limiting wheel body 60 are in contact with the guide rod body 44. The above configuration, through the setting of the first limiting wheel body 60 and the second limiting wheel body 60, utilizes the hinged cooperation between the limiting connecting plate 51 and the limiting wheel frame 53. When the fixture assembly undergoes slight torsion, the position of the limiting wheel frame 53 will be adjusted accordingly, so that the first limiting wheel body 60 and the second limiting wheel body 60 are always in contact with the guide rod body 44, thereby adapting to the positional deviation caused by the misalignment of the workpiece sample 15 and the actuator 1 axis during the test.

[0065] In some embodiments, the limiting wheel assembly 5 further includes a rolling shaft and a self-aligning ball bearing 58. The limiting wheel body 60 is mounted on the rolling shaft to ensure that the limiting wheel body 60 can rotate smoothly. The rolling shaft is mounted on the limiting wheel frame 53 through the self-aligning ball bearing 58. The self-aligning ball bearing 58 is used to finely adjust the angle of the rolling shaft so that the limiting wheel body 60 fits against the guide rod body 44 to ensure the limiting effect on the limiting wheel body 60.

[0066] In some embodiments, the limiting wheel assembly 5 further includes several oil seal 55 components and oil seal 55 positioning sleeves, both of which are mounted on the limiting wheel frame 53; specifically, the oil seal 55 components can prevent lubricating oil from flowing out, and the oil seal 55 positioning sleeves include a first oil seal positioning sleeve 56 and a second oil seal positioning sleeve 59, which respectively position the corresponding oil seal 55 components.

[0067] The flexible connection fatigue testing machine fixture device provided by this invention is mainly used for static and dynamic fatigue testing of workpiece samples 15 such as wind turbine blade roots and bolt sleeves. The upper part of the fixture device is connected to the upper crossbeam A and the piston rod of the hydraulic cylinder of the fatigue testing machine, and the lower part is connected to the base D. There are four guide rod assemblies 4, which are evenly connected to the lower surface of the crossbeam A by screws. The guide rod assemblies 4 move with the crossbeam A. The guide base plate 45 and the disc spring clamping pad of the guide rod assembly 4 are in contact with the column C. The spring clamping pad 48 is tightly fitted with the column C under the action of the spring component 49. The connecting column of the actuator 1 is connected to the piston rod of the hydraulic cylinder, and the bolt at the upper end of the workpiece sample 15 is connected to the upper adjusting shim 13 of the fixture, so that the bolt at the upper end of the workpiece sample 15 moves with the piston rod of the hydraulic cylinder. During the movement, the limiting wheel body 60 of the limiting wheel assembly 5 cooperates with the guide rod body 44 and performs rolling and sliding motion; the lower fixing plate 18 of the lower part is connected to the base D; the lower connecting side plate 16 of the workpiece is connected to the lower platform plate 17 and the lower end side of the workpiece sample 15; the bolt at the lower end of the workpiece sample 15 is connected to the lower adjusting shim 14 of the fixture.

[0068] Specifically, in one embodiment, when the wind turbine blade root workpiece specimen 15 undergoes fatigue testing, due to the structural characteristics of the workpiece specimen 15, the testing machine fixture assembly fixedly connected to it is bolted. The upper end of the workpiece specimen 15 is bolted to the clamping connection base plate 12, and the lower end of the workpiece specimen 15 is bolted to the lower connecting side plate 16. Since the workpiece specimen 15 is undergoing fatigue load testing, and the actuator 1 is arranged above it, the connecting fixture above the workpiece specimen 15 needs to be made into a follower device. At the same time, to prevent the workpiece specimen 15 from deviating from the axial direction due to installation position deviation and radial force on the hydraulic cylinder under tension, the connecting fixture also needs to add a soft connection device to counteract the radial force on the actuator 1.

[0069] Basic plan:

[0070] When the workpiece specimen 15 is subjected to fatigue load, its upper connection position reciprocates, causing the point of force application that causes displacement to be at the connecting post of the actuator 1. The thread at the end of the connecting post of the actuator 1 is screwed into the chuck connecting flange 3, and the locking washer 2 eliminates the thread gap generated by the connection. The outer ring of the chuck connecting flange 3 has multiple screws that are fixedly connected to the corresponding threaded holes of the upper fixing plate 7. The center position of the upper fixing plate 7 is coaxially connected to the upper platform plate 10 through the spherical bearing 20 and the upper hinge shaft 8. The T-shaped platform of the upper platform plate 10 is downward to embed the clamping connecting plate 11. Similarly, the T-shaped platform at the lower end of the clamping connecting plate 11 is embedded in the T-shaped platform of the clamping connecting base plate 12. The workpiece specimen 15 passes through the middle position of the clamping connecting base plate 12, thus leaving a gap between the upper platform plate 10 and the clamping connecting base plate 12. There is a relatively large gap, which allows for operations such as placing fasteners 50-2 on top of the workpiece specimen 15 through which the test is conducted. At this point, the four-column C-type flexible connection fatigue testing machine fixture B transmits the reciprocating motion of the actuator 1 to the clamping fixture of the workpiece specimen 15. Since the upper fixed plate 7 and the upper platform plate 10 are connected by a spherical bearing 20, which has a universal function, the eccentric force generated by the workpiece specimen 15 during the test is transferred to the guide rod assembly 4 through the limit wheel assembly 5. This reduces the radial force of the actuator 1, thus achieving the function of a flexible connection.

[0071] The aforementioned tooling, which moves with actuator 1, lacks a guiding auxiliary device. To ensure that the force direction of the workpiece sample 15 remains on the axis of actuator 1 and to guarantee the accuracy of the test data, a guiding auxiliary device needs to be added to the moving tooling. The guide rod assembly 4 is fixed outward to the four columns C, and its top is fixedly connected to the crossbeam A of the testing machine by the crossbeam fixing component 41. Its position is determined by the position of the crossbeam A of the testing machine. Inward, it cooperates with the limiting wheel assembly 5 to form a sliding pair. The limiting wheel assembly 5 is designed with a mechanism for adaptively adjusting the guide rod body 44. Its structure consists of two limiting wheel bodies 60 that are attached to the guide rod body 44 and roll up and down. The other end of the limiting wheel frame 53 where the two limiting wheel bodies 60 are located is hinged to the limiting connecting plate 51. The limiting connecting plate 51 is fixed to the upper fixed plate 7 by screws. Therefore, when the upper fixed plate 7 moves up and down with the workpiece sample 15, the limiting wheel assembly 5 always provides guidance on the guide rod body 44 of the fixed guide rod assembly 4. When installing the upper fixture, in order to prevent the rotation of the intermediate fixture from affecting the guide auxiliary device to deviate from the four columns C, an anti-rotation component 6 is also provided on the upper fixed plate 7. After the axial angle of the upper fixture is determined, the anti-rotation component 6 is directly inserted into the crossbeam A to lock the axial angle position of the upper fixed plate 7 and its fixedly connected components so that it will not change.

[0072] The components that move together with the fixed installation of the workpiece sample 15 include: the connecting column of the actuator 1, the locking pad 2, the clamp connecting flange 3, the limit wheel assembly 5, the upper fixing plate 7, the upper platform plate 10, the clamping connecting plate 11, and the clamping connecting base plate 12. These tooling components form the upper fixed connection device for the workpiece sample 15. A spherical bearing 20 is installed between the upper fixing plate 7 and the upper platform plate 10, with a certain gap between them. When the workpiece sample 15 is under tension and deflects, the gap ensures that no movement interference occurs. The guide rod assembly 4 is fixed to the column C and the crossbeam A. The limit wheel assembly 5, which is connected to the upper fixing plate 7, reciprocates on the guide rod assembly 4 to provide guidance. A spherical bearing 20 is also provided at the lower end of the workpiece sample 15, installed between the lower platform plate 17 and the lower fixing plate 18, which also serves to adjust the workpiece sample 15 to prevent radial force.

[0073] The specific implementation of the present invention is as follows: The lower part of the workpiece sample 15 is fixedly connected to the lower connecting plate of the workpiece, and its position does not change. The upper part is fixedly connected to the clamping connecting plate 11 and moves with it. When the workpiece sample 15 deviates from the vertical axis of the tooling, the joint bearing 20 between the upper fixed plate 7 and the upper platform plate 10 and the joint bearing 20 between the lower fixed plate 18 and the lower platform plate 17 play a role in canceling the radial force on the actuator 1 and the workpiece sample 15, so that it only bears the tensile force, and plays a soft connection role. The guide rod assembly 4 is an auxiliary guide part, consisting of four identical parts, each circumferentially spaced at 90-degree angles and tightly gripping the four columns C. The way it grips the four columns C is that a spring clamping pad 48 is equipped with a spring component 49 behind it. The spring clamping pad 48 is subjected to the force of the spring component 49, so that the spring clamping pad 48 produces the effect of sticking tightly to the four columns C. Thus, the guide rod assembly 4 can grip the four columns C tightly by the clamping force of the spring component 49 without external force, and does not fall down along the four columns C. At this time, the maximum static friction is greater than the effect of gravity. When the test requires moving the upper crossbeam A, since the crossbeam fixing component 41 is fixed on the crossbeam A, when the crossbeam A moves up or down, it drives the guide rod assembly 4 to move up and down. At this time, the external force applied to the up and down movement of the crossbeam A is greater than the weight of the guide rod assembly 4 plus the maximum static friction. When the position of the crossbeam A is determined, the position of the guide rod assembly 4 is determined, that is, the "track" is arranged. When actuator 1 is activated, the connecting column of actuator 1 vibrates up and down at a certain frequency under the action of force, driving the fixedly connected parts to move up and down. As mentioned earlier, the upper fixed plate 7 is the part that follows the connecting column of actuator 1. Therefore, the upper fixed plate 7 drives the limiting wheel assembly 5 to vibrate up and down. Since the limiting wheel assembly 5 and the guide rod assembly 4 move up and down on the fixed track, the fixture assembly of the whole workpiece sample 15 does not produce rotational movement, achieving the effect of only vibrating up and down. The limiting wheel assembly 5 consists of two limiting wheel bodies 60 mounted on the same horizontal frame. A limiting hinge shaft 52 is provided on the symmetrical plane between the two axes. The limiting hinge shaft 52 and the two limiting roller shafts 57 form an equilateral triangle structure. The frame composed of the three can rotate freely around the limiting hinge shaft 52. If the arrangement direction of the two limiting wheel bodies 60 is not parallel to the guide rod body 44, the limiting wheel frame 53 can rotate adaptively around the limiting hinge shaft 52.

[0074] The distinctive feature of the device of the present invention is that it eliminates the radial force between the actuator 1 and the workpiece sample 15, and the workpiece sample 15 will not rotate when vibrating at a certain frequency under the clamping of the clamping fixture.

[0075] In addition to the aforementioned clamping device, the present invention also provides a fatigue testing machine including the aforementioned clamping device. The number of clamping devices can be multiple, and the number of clamping devices can be the same as the number of columns C, and they correspond one-to-one. The fatigue testing machine can be a four-column fatigue testing machine, and the corresponding number of clamping devices can also be four. For the structure of other parts of the fatigue testing machine, please refer to the relevant technology, which will not be repeated here.

[0076] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0077] The clamping device provided by the present invention has been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of the present invention. The descriptions of the embodiments above are only for the purpose of helping to understand the method and core ideas of the present invention. It should be noted that those skilled in the art can make several improvements and modifications to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the protection scope of the present invention.

Claims

1. A clamping device applied to a fatigue testing machine, the fatigue testing machine comprising an actuator (1), a crossbeam (A), a column (C), and a base (D), characterized in that, include: A clamping fixture is used to clamp the workpiece sample (15). The clamping fixture is connected between the actuator (1) and the base (D) so that the actuator (1) can stretch the workpiece sample (15). The guide rod assembly (4) includes a beam fixing component (41), a guide rod body (44), and a column guide assembly. The beam fixing component (41) is disposed on the beam (A). The guide rod body (44) is swayably disposed on the beam fixing component (41). The column guide assembly is installed on the column (C). The column guide assembly can slide relative to the column (C). When the angle of the guide rod body (44) is determined, the guide rod body (44) can be fixed on the column guide assembly. The limiting wheel assembly (5) includes a limiting connecting plate (51), a limiting wheel frame (53), and a limiting wheel body (60). The limiting connecting plate (51) is connected to the clamping fixture. The horizontal position of the limiting connecting plate (51) is adjustable. The limiting wheel frame (53) is hinged to the limiting connecting plate (51). The limiting wheel body (60) is rotatably mounted on the limiting wheel frame (53). The limiting wheel frame (53) has a limiting space for the guide rod body (44) to be inserted. The limiting wheel body (60) and the guide rod body (44) are attached and slidably connected. The limiting wheel body (60) includes a first limiting wheel body (60) and a second limiting wheel body (60). The first limiting wheel body (60) and the second limiting wheel body (60) are arranged along the extension direction of the guide rod body (44). The circumferential surfaces of the first limiting wheel body (60) and the second limiting wheel body (60) are provided with a rolling structure that matches the outer circumferential shape of the guide rod body (44). The limiting wheel assembly (5) also includes a limiting hinge shaft (52). The limiting hinge shaft (52) is connected between the limiting connecting plate (51) and the limiting wheel frame (53). The limiting hinge shaft (52) extends in the horizontal direction. The limiting wheel frame (53) can swing in the vertical direction so that the first limiting wheel body (60) and the second limiting wheel body (60) are both in contact with the guide rod body (44).

2. The clamping device according to claim 1, characterized in that, The guide rod assembly (4) further includes a guide rod fixing plate (43) and a guide shaft (42). The guide shaft (42) is connected between the crossbeam fixing component (41) and the guide rod body (44), and the guide rod body (44) can swing radially relative to the actuator (1). The guide rod fixing plate (43) is fixedly connected to the guide rod body (44), and the guide rod fixing plate (43) is detachably fixed on the column guide assembly.

3. The clamping device according to claim 1, characterized in that, The column guide assembly includes a guide connecting plate (46), a guide base plate (45), and a spring connecting assembly. The guide rod body (44) can be fixed on the guide base plate (45). The guide connecting plate (46) is installed on the guide base plate (45), and the spring connecting assembly is installed on the guide connecting plate (46). The column (C) is located between the spring connecting assembly and the guide base plate (45), and the spring connecting assembly can press against the surface of the column (C).

4. The clamping device according to claim 3, characterized in that, The spring connecting assembly includes a spring base plate (47), a spring clamping pad (48), a spring component (49), and a spring force adjustment assembly. The spring base plate (47) is connected to the guide connecting plate (46). The spring clamping pad (48) is provided with a clamping surface for cooperating with the column (C). The spring base plate (47) is located on the side of the spring clamping pad (48) away from the clamping surface. The spring component (49) is disposed between the spring base plate (47) and the spring clamping pad (48). The spring force adjustment assembly passes through the spring base plate (47) and the spring clamping pad (48), and the spring force adjustment assembly changes the spring force of the spring component (49) by adjusting the distance between the spring base plate (47) and the spring clamping pad (48).

5. The clamping device according to claim 4, characterized in that, The elastic adjustment assembly includes a guide sleeve (50-1) and a fastener (50-2). The spring base plate (47) and the spring pressing pad (48) are provided with a groove on the side close to each other for the spring component (49) to be inserted. There is a gap between the spring base plate (47) and the spring pressing pad (48). The spring pressing pad (48) is provided with a first step on the side close to the pressing surface. The guide sleeve (50-1) is engaged with the first step. The spring base plate (47) is provided with a second step on the side away from the spring pressing pad (48). The fastener (50-2) is engaged with the second step. The guide sleeve (50-1) and the fastener (50-2) are connected by a threaded connection to adjust the width of the gap. Furthermore, after the spring connecting assembly is fitted to the column (C), the fastener (50-2) is loosened to reset the spring component (49) and press the spring clamping pad (48) onto the column (C).

6. The clamping device according to claim 1, characterized in that, The clamping fixture includes, from top to bottom, an upper fixed plate (7), an upper platform plate (10), a clamping connecting plate (11), a clamping connecting base plate (12), a lower platform plate (17), and a lower fixed plate (18). The clamping connecting plate (11) extends vertically and is detachably connected between the upper platform plate (10) and the clamping connecting base plate (12). The top of the upper fixed plate (7) is connected to the actuator (1). 7) The bottom of the plate is hinged to the upper plate (10), the lower plate (17) is hinged to the lower fixed plate (18), and the workpiece sample (15) is clamped between the clamping connecting base plate (12) and the lower plate (17); and / or, it also includes an anti-rotation component (6), which is disposed on the upper fixed plate (7) and is used to engage with the crossbeam (A) to restrict the upper fixed plate (7) from rotating circumferentially along the actuator (1).

7. The clamping device according to claim 6, characterized in that, The clamping connecting plate (11) is an I-shaped plate. The bottom of the upper platform plate (10) and the top of the connecting base plate are respectively provided with a plurality of sliding grooves for the clamping connecting plate (11) to slide into and engage in the vertical direction. The width of the connecting base plate is smaller than the width of the upper platform plate (10). The width of the clamping connecting plate (11) is the same as the width of the connecting base plate. The upper platform plate (10) is also provided with a clamping top block (11-2) in the sliding groove. The clamping fixture also includes a plurality of clamping baffles (11-1). The clamping baffles (11-1) are provided at the ends of the sliding grooves to block the clamping connecting plate (11) or the clamping top block (11-2).

8. The clamping device according to claim 1, characterized in that, The limiting wheel assembly (5) also includes a limiting rolling shaft and a self-aligning ball bearing (58). The limiting wheel body (60) is mounted on the limiting rolling shaft. The limiting rolling shaft is mounted on the limiting wheel frame (53) via the self-aligning ball bearing (58). The self-aligning ball bearing (58) is used to finely adjust the angle of the limiting rolling shaft so that the limiting wheel body (60) fits against the guide rod body (44).

9. A fatigue testing machine, comprising a plurality of clamping devices, characterized in that, The clamping device is the clamping device according to any one of claims 1 to 8.

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