A catheter rotary bending fatigue test apparatus
Patent Information
- Application Number
- CN202522242851.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-10-23
- Publication Date
- 2026-10-16
- Estimated Expiration
- 2035-10-23
Smart Images
Figure CN224861440U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of mechanical property testing technology for rotating components, specifically to a device for testing the rotational bending fatigue of a conduit. Background Technology
[0002] Rotating components, such as oil pipelines that rotate in or synchronously with rotating shaft systems, need to undergo rotational bending fatigue testing to verify their mechanical properties and assess their service reliability in order to avoid cascading accidents caused by accidental fatigue fracture.
[0003] Due to factors such as installation benchmark deviations of upstream and downstream equipment and cumulative assembly errors of multiple components, the axial centers at the connection points of the two ends of the conduit are difficult to be perfectly aligned, inevitably resulting in the conduit being in an eccentric installation state. However, traditional rotational bending test equipment, based on the ideal assumption of concentric installation, can only simulate the stress state when the axial centers of the two ends of the conduit are perfectly aligned. It lacks the ability to conduct rotational bending fatigue tests on conduits in eccentric states, cannot match actual eccentric installation conditions, and has insufficient reliability and accuracy of test results.
[0004] This disconnect between test conditions and actual assembly conditions can lead to a series of risks: the risk of stress concentration caused by installation eccentricity may be underestimated, potentially leading to sudden duct breakage; the fatigue life of the duct may be misjudged, potentially causing premature breakage; and the breakage will cause fluid leakage inside the duct, which in turn can trigger a chain of accidents and affect the aircraft. Utility Model Content
[0005] Therefore, this application provides a duct rotation bending fatigue testing device to solve the problem that existing testing devices cannot be matched with eccentric installation conditions.
[0006] To achieve the above objectives, this application provides the following technical solution: A device for testing the rotational bending fatigue of a conduit includes: A rotary driver, wherein the output shaft of the rotary driver rotates about the first straight line, and the output shaft is provided with a dial indicator, the probe of which is used to contact the mounting part to detect the amount of offset of the mounting part along the radial direction of the output shaft; The mounting part has one end of the conduit connected to the output shaft and the other end of the conduit rotatably connected to the mounting part. The support base is provided with a first driving device for driving the mounting part to move radially along the output shaft and to maintain its position after movement; A loading element is used to apply a bending load perpendicular to the first straight line to the conduit; A failure detection device is used to detect the failure characteristics of the catheter and characterize the fatigue failure state of the catheter. A strain measuring device is provided, wherein the strain gauge of the strain measuring device is attached to the outer surface of the conduit, the length direction of the strain gauge is consistent with the axial direction of the conduit, and a gap is provided between the strain gauge and the axis of the conduit along the offset direction of the mounting part.
[0007] Optionally, the failure detection device includes: A fluid supply device, wherein the output end of the fluid supply device passes through the mounting base and is sealed to one axial end of the conduit, and the other axial end of the conduit is sealed; A pressure monitoring device is used to monitor the fluid pressure at the output end of the fluid supply device.
[0008] Optionally, the loading element includes: Controller; The displacement section is connected to one end of the conduit near the first rotating shaft. The controller is used to drive the displacement section to deflect radially along the output shaft. The second straight line is perpendicular to the first straight line. The probe of the dial indicator is also used to contact the displacement section to detect the amount of radial displacement of the displacement section along the output shaft.
[0009] Optionally, the first driving device includes a first lead screw linear displacement mechanism, the mounting part is connected to the support base through the first lead screw linear displacement mechanism, the mounting part is connected to the driven member of the first lead screw linear displacement mechanism, and the linear displacement direction of the first lead screw linear displacement mechanism is perpendicular to the first straight line.
[0010] Alternatively, the axial end of the active lead screw of the first lead screw linear displacement mechanism is provided with a handle.
[0011] Compared with existing technologies, this application can simulate the working condition of eccentric installation and conduct rotational bending fatigue tests under this condition. The test results are more accurate and can reduce the operational risks of related equipment. Attached Figure Description
[0012] To more intuitively illustrate the prior art and this application, several exemplary figures are provided below. It should be understood that the specific shapes and structures shown in the figures should not generally be regarded as limiting conditions for implementing this application; for example, based on the technical concept disclosed in this application and the exemplary figures, those skilled in the art are able to easily make conventional adjustments or further optimizations to the addition / reduction / classification, specific shapes, positional relationships, connection methods, size ratios, etc. of certain units (components).
[0013] Figure 1 This is a schematic diagram of the structure of a duct rotational bending fatigue testing device provided in one embodiment of this application; Figure 2 for Figure 1Left-side stereoscopic view of the embodiment; Figure 3 for Figure 2 A magnified view of a portion of the image; Figure 4 for Figure 1 Right-side stereoscopic view of the embodiment; Figure 5 for Figure 1 Side perspective view of the embodiment; Figure 6 for Figure 1 A schematic diagram of the loading component provided in the embodiment; Figure 7 for Figure 6 Side view perspective structural diagram of the embodiment; Figure 8 for Figure 6 A bottom-view perspective view of the embodiment; Figure 9 for Figure 6 Top view of the embodiment; Figure 10 for Figure 6 A schematic diagram of the structure of the first guide mechanism provided in the embodiment; Figure 11 for Figure 6 A schematic diagram of the structure of the second slider provided in the embodiment; Figure 12 for Figure 6 A schematic diagram of the structure of the first rotating seat provided in the embodiment; Figure 13 for Figure 12 A structural diagram of the back side; Figure 14 for Figure 6 A schematic diagram of the structure of the first follower provided in the embodiment; Figure 15 for Figure 6 A schematic diagram of the structure of the first follower provided in the embodiment; Figure 16 for Figure 6 A schematic diagram of the connection part provided in the embodiment; Explanation of reference numerals in the attached figures: Rotary driver 100, output shaft 110, support base 200, mounting part 300, handle 310, oil filling platform 410, pressure testing device 420, loading element 500, fourth guide mechanism 510, first guide rail 511, second guide rail 512, second slider 513, fourth rotating seat 520, preset cavity 521, first opening 522, second opening 523, fourth follower 530, receiving cavity 531, fourth screw 540, drive slot 541, connecting part 550, first through hole 551, locking screw 560, moving screw 570, guide tube 600. Detailed Implementation
[0014] The present application will be further described in detail below with reference to the accompanying drawings and specific embodiments.
[0015] In the description of this application: unless otherwise stated, "a plurality of" means two or more. The terms "first," "second," "third," etc., in this application are intended to distinguish the objects referred to and do not have any special meaning in terms of technical connotation (e.g., they should not be construed as an emphasis on importance or order). Expressions such as "including," "comprising," and "having" also mean "not limited to" (certain units, components, materials, steps, etc.).
[0016] The terms used in this application, such as "upper," "lower," "left," "right," and "middle," are generally used to facilitate intuitive understanding by referring to the accompanying drawings, and are not absolute limitations on the positional relationships in the actual product. Changes in these relative positional relationships, without departing from the technical concept disclosed in this application, should also be considered within the scope of this application.
[0017] This application provides a duct rotational bending fatigue testing device, including a rotary actuator 100, a mounting part 300, a support base 200, a loading element 500, a failure detection device, a dial indicator, and a strain measurement device. Wherein: One end of the conduit 600 is connected to the output shaft 110, and the other end of the conduit 600 is rotatably connected to the mounting part 300; the support base 200 is provided with a first driving device for driving the mounting part 300 to move radially along the output shaft 110, and to maintain its position after movement; The output shaft 110 of the rotary actuator 100 rotates about a first linear axis. A dial indicator is mounted on the output shaft 110, and the dial indicator is fixedly connected to the output shaft 110, preferably in a detachable manner. For example, the dial indicator's mounting base can be magnetically attached to the stationary side wall of the rotary actuator 100, or it can be clamped or bolted. The key is to ensure that the dial indicator's mounting base and its mounting position remain relatively stationary and fixed in the connected state, preventing easy detachment due to slight interaction between the probe and the measured structure. The dial indicator's probe contacts the mounting portion 300 to detect the radial offset of the mounting portion 300 along the output shaft 110. Specifically: The mounting section 300 is equipped with a bearing for rotatable connection to one end of the guide tube 600. The outer surface of the mounting section 300 is cylindrical and coaxial with the bearing. Adjust the position of the mounting section 300 so that the bearing axis coincides with the first straight line. Use a dial indicator to check if the mounting section 300 is accurately positioned. First, place the dial indicator head (i.e., the probe) on the mounting section 300 and observe the dial reading. Rotate the output shaft 110 90° and stop to observe the dial reading again. Check if the data fluctuation is within the allowable ±0.05 deviation range. If it exceeds the range, continue to adjust the position of the mounting section 300 until it is qualified. If the outer wall of the mounting section 300 is irregular, the dial indicator head can be placed on the bearing of the mounting section 300, as long as the axis of the bearing and the output shaft 110 can be aligned as much as possible within the allowable error range.
[0018] The loading element 500 is used to apply a bending load perpendicular to the first straight line to the conduit 600, and the application position is located at one end of the conduit 600 near the output shaft 110. This application does not specifically limit the loading element 500 for applying the bending load, as long as it can complete the required bending process.
[0019] The failure detection mechanism is used to detect the failure characteristics of the conduit 600 and characterize the fatigue failure state of the conduit 600; the strain gauge of the strain measuring device is attached to the outer surface of the end of the conduit 600 near the mounting part 300, the length direction of the strain gauge is consistent with the axial direction of the conduit 600, and a gap is provided between the strain gauge and the axis of the conduit 600 along the offset direction of the mounting part 300.
[0020] One end of the conduit 600 is rotatably connected to the mounting part 300. Strain gauges are attached to the conduit 600. After radially offsetting the mounting part 300, the other end of the conduit 600 is connected to the output shaft 110. At this time, the conduit 600 is in an overall eccentric installation state. Subsequently, a radial load is applied to simulate bending. Then, the bent conduit 600 is driven by the rotary actuator 100 to rotate continuously in this eccentric installation state. The failure characteristics of the conduit 600 are detected by a failure detection mechanism to determine whether the conduit 600 has failed and to determine the fatigue life of the conduit 600.
[0021] Due to the necessary assembly clearances of each component, and the influence of factors such as micro-displacement, deformation, wear, or loosening of each component under rotational load, the mounting part 300, which was originally locked and positioned by the first drive device, will experience a slight offset. Therefore, in the rotational fatigue test of the eccentrically mounted conduit 600, there is a risk that the actual radial offset of one end of the conduit 600 will gradually decrease during rotation. The reduction in the measured offset leads to a decrease in actual stress, a slower fatigue damage rate, and an extended fatigue life. However, if the measurement result is still taken as the fatigue life obtained under a fixed offset, the fatigue life of the conduit 600 will be overestimated, resulting in the risk of premature breakage of the conduit 600 during use. In order to control the change in offset during rotation within an acceptable deviation range, this application adds a strain gauge, specifically: Before the conduit 600 rotates, strain gauges monitor the local tensile deformation state of the conduit 600 under these conditions. The original state is observed, with bending deformation occurring at the other end of the conduit 600 along its axial direction, and cracks also occurring at the other end, outside the measurement range of the strain gauges. During rotation, if the offset of the mounting part 300 decreases, the tension caused by its eccentricity decreases, the tensile deformation decreases, and the strain gauge data decreases. If the decrease exceeds the deviation range, rotation can be stopped, and the mounting platform position can be readjusted using the first drive device until the strain gauge data returns to its original state or its data deviation returns to the deviation range, before restarting rotation.
[0022] Compared with existing technologies, this application can simulate the working condition of eccentric installation and conduct rotational bending fatigue tests under this condition. The test results are more accurate and can reduce the operational risks of related equipment.
[0023] The guide tube rotational bending fatigue testing equipment provided in this application is modified from an existing drilling rig, which is low in cost and conducive to widespread application. Furthermore, the equipment vertically installs the guide tube, making it easier to quickly load and unload the guide tube compared to existing technologies.
[0024] In one possible implementation, the failure detection device includes a fluid supply device and a pressure testing device 420. This application does not limit the specific fluid supplied by the fluid supply device; it can be flexibly configured according to the type of conduit 600. If the rotating sample is an oil conduit 600, an oil injection platform 410 is used, and the supplied fluid is oil. If the rotating sample is a gas conduit, a corresponding gas supply device is used, and the supplied fluid is gas. Alternatively, the rotating bending fatigue testing device for the conduit 600 can be equipped with two types of fluid supply devices, both detachably connected via rotary joints. The output end of the fluid supply device corresponding to the type of conduit 600 being measured is sealed and connected to the conduit 600. The output end of the fluid supply device passes through a mounting base and is sealed and connected to one axial end of the conduit 600, while the other axial end of the conduit 600 is sealed. The pressure monitoring device is used to monitor the fluid pressure at the output end of the fluid supply device.
[0025] Once fatigue failure causes cracks in the originally closed fluid channel, fluid leaks out, causing a drop in oil / gas pressure. Monitoring pressure is used to detect fluid leakage, thereby determining whether the conduit 600 has failed due to bending loads and rotational fatigue. Therefore, the pressure monitoring equipment can detect the failure characteristics of the conduit 600, and the measured fluid pressure data can be used to characterize the fatigue failure state of the conduit 600.
[0026] In one possible implementation, the fluid supply device is an oil injection platform 410, with the oil injection port of the oil injection platform 410 sealed and connected to the axial opening of the conduit 600 mounted on the mounting part 300. Preferably, the axial end of the conduit 600 is rotatably connected to the mounting part 300, and the tubular opening at this end of the conduit 600 is sealed and connected to one end of the connecting channel opened in the mounting part 300. The oil injection port of the oil injection platform 410 is sealed and connected to the other end of the connecting channel. That is, the oil injection port is indirectly sealed and connected to one end of the conduit 600 through the connecting channel of the mounting part 300. It should be noted that the rotating conduit 600 and the stationary fluid supply device output end / the connecting channel end of the mounting part 300 are sealed and connected through a rotary joint with good sealing performance. This is an inherent structure in the rotating bending fatigue testing equipment for sealing the connection between the rotating specimen and the stationary device, and will not be elaborated upon in this application.
[0027] In one possible implementation, the first driving device includes a first lead screw linear displacement mechanism. The mounting part 300 is connected to the support base 200 via the first lead screw linear displacement mechanism. The mounting part 300 is connected to the driven member of the first lead screw linear displacement mechanism, and the linear displacement direction of the first lead screw linear displacement mechanism is perpendicular to a first straight line. Optionally, a handle 310 (preferably a wheel) is provided at one axial end of the driving lead screw of the first lead screw linear displacement mechanism, allowing manual driving of the mounting part 300.
[0028] Optionally, the first drive device further includes a second lead screw linear displacement mechanism. The first lead screw linear displacement mechanism is connected to the mounting base via the second linear displacement mechanism. Specifically, in both the first and second lead screw linear displacement mechanisms, the driving member rotates on its rotating seat. The rotating seat of the first lead screw linear displacement mechanism is connected to the driven member of the second lead screw linear displacement mechanism. The rotating seat of the second linear displacement mechanism is connected to the mounting base. The driving member of the second linear displacement mechanism is provided with a handle 310 (preferably a rotating wheel). The moving direction of the driven member of the first lead screw linear displacement mechanism is perpendicular to that of the second lead screw linear displacement mechanism, and both are perpendicular to the first linear displacement mechanism.
[0029] In one possible implementation, the support base 200 is further provided with a second driving device, which is connected to the support base 200. The first driving device is indirectly connected to the support base 200 through its connection with the driving end of the second driving device. The second driving device drives the first driving device and its connected load mounting part 300 to linearly displace along a first linear direction. This application does not limit the driving structure of the second driving device; it can be a motor, hydraulic equipment, etc., that outputs a linear displacement shaft, or a third lead screw linear displacement mechanism. The rotating seat of the driving member is connected to the support base 200, and a handle 310 is provided at one axial end of the driving member. The driven member is connected to the first driving device (e.g., the rotating seat of the first / second lead screw linear displacement mechanism in the two aforementioned embodiments).
[0030] In one possible implementation, there are two or more strain gauges, spaced apart along the offset direction of the mounting portion 300. The strain gauges are located at one end of the conduit 600 along the offset direction of the mounting portion 300, for example, at the end with the largest / smallest radius of rotation.
[0031] This application does not specify the connection method between the strain gauge rotating with the guide tube 600 and the stationary strain gauge for observing the measurement results. As long as an electrical connection can be achieved to complete communication, it is acceptable. This is an inherent structure of strain gauges for measuring the strain of rotating components, and this application will not elaborate on it. For example, the strain gauge can be wirelessly connected to the strain gauge, unaffected by the rotation of the component. Alternatively, the strain gauge can be connected to the strain gauge via an electrical slip ring. The operation of changing the strain gauge and reconnecting the strain gauge when testing different guide tubes 600 is also a conventional and inherent mechanism of strain measurement devices, and this application will not elaborate on it either, nor should it be construed as a limitation of this application.
[0032] In one possible implementation, the loading element 500 includes a controller and a displacement unit. The displacement unit is connected to one end of the conduit 600 near the first rotating shaft. The controller is used to drive the displacement unit to deflect radially along the output shaft 110. The second straight line is perpendicular to the first straight line. The probe of the dial indicator is also used to contact the displacement unit to detect the amount of radial displacement of the displacement unit along the output shaft 110.
[0033] In one possible implementation, the loading element 500 includes a fourth lead screw linear displacement mechanism, a connecting part 550, and a locking screw 560. The fourth lead screw linear displacement mechanism includes a fourth follower 530 and a fourth guide mechanism 510. The fourth guide mechanism 510 is connected to the output shaft 110. The displacement direction of the fourth follower 530 is perpendicular to the first straight line. The connecting part 550 has a first through hole 551 that matches the guide tube 600. One axial end of the guide tube 600 is sleeved in the first through hole 551 and is detachably fixedly connected to the first through hole 551 and / or the fourth follower 530. The other axial end is detachably rotatedly connected to the mounting part 300, for example, with a transition fit or a small interference fit, and the rotation axis is consistent with the axis of the output shaft 110. The axial direction of the locking screw 560 is consistent with the axial direction of the output shaft 110. The end of the locking screw 560 away from its head (also called the threaded end of the locking screw 560) passes through the connecting part 550 and the fourth follower 530 in sequence and then abuts against the fourth guide mechanism 510. The locking screw 560 is threadedly connected to its through-connection portion 550 and / or the fourth follower 530. The threaded connection has a certain degree of self-locking property; therefore, as long as the locking screw 560 is not rotated and remains through-connected, the locking screw 560 can remain stationary relative to both, and the fourth follower 530 and the connection portion 550 can be synchronously displaced. "Abutting" refers to the physical contact between the surfaces of two components, where a definite force is applied or borne by each other. In this application, "abutting" means that, based on the contact between the locking screw 560 and the fourth guide mechanism 510, the locking screw 560 is rotated to bring its head closer to the fourth guide mechanism 510, thereby applying a force perpendicular to the sliding direction of the fourth follower 530 to the fourth guide mechanism 510 using the locking screw 560 on the fourth follower 530, forming a frictional force that resists the sliding of the fourth follower 530.
[0034] As is well known, all lead screw linear displacement mechanisms include a driving member, a driven member, a rotary seat for rotating the driving member, and a guiding mechanism that restricts the rotation of the driven member and guides the driven member to move linearly along the thread axis. This is an inherent structure of lead screw linear displacement mechanisms. For ease of understanding, only the differences from the inherent structure are described; the inherent structural parts without structural improvements are not elaborated upon and should not be construed as lacking relevant components in this application. In other words, the fourth lead screw linear displacement mechanism provided in this application includes a fourth driving member, a fourth driven member 530, a fourth rotary seat 520, and a fourth guiding mechanism 510. Furthermore, the fourth driving member is the controller for the loading member, and the fourth driven member 530 is the displacement part of the loading member. The structure of each component and their interrelationships are also inherent structures of lead screw linear displacement mechanisms and will not be elaborated upon in this application.
[0035] A sliding clearance needs to be provided between the fourth driven member 530 and the fourth guide mechanism 510 of the fourth lead screw linear displacement mechanism to allow the fourth driven member 530 to slide on the fourth guide mechanism 510. This is an inherent structure of the lead screw linear displacement mechanism and will not be elaborated upon in this application. In this embodiment, a locking screw 560 is provided on the fourth driven member 530. Tightening the locking screw 560 so that its threaded end abuts against the fourth guide mechanism 510 applies pressure perpendicular to the sliding direction of the fourth driven member 530 to the fourth guide mechanism 510, forming a frictional force that resists the sliding of the fourth driven member 530 and locks the sliding displacement of the fourth driven member 530. Loosening the locking screw 560 so that its threaded end contacts the fourth guide mechanism 510 without force, or directly leaves the fourth guide mechanism 510, canceling the increased frictional force due to the abutment, allows the fourth driving member to be rotated, and the fourth driven member 530 can slide normally on the fourth guide mechanism 510.
[0036] In this embodiment, the fourth guide mechanism 510 and the fourth rotating seat 520 are fixed to the output shaft 110. The connecting part 550 and the fourth driven member 530 are synchronously displaced, and the displacement direction is the rotational radial direction of the output shaft 110. Therefore, the displacement of the fourth driven member 530 can drive the axial end of the conduit 600 within the first perforation 551 (or within the first perforation 551 and the accommodating cavity 531 if the fourth driven member 530 has an accommodating cavity 531) to shift radially. In other words, compared with the prior art, the loading member 500 of this application can apply a radial load to an axial end of the conduit 600, causing the axial end of the conduit 600 to undergo local bending deformation.
[0037] This application utilizes a rotary actuator 100 to rotate a bent and deformed conduit 600 to test its fatigue performance under multiple rotations in a bent state. Failure detection can be performed using an external mechanism or by the failure detection device built into the bending fatigue testing machine for the conduit 600. This application does not specifically limit the type of failure detection. It can be real-time dynamic monitoring, such as the oil injection platform 410 for real-time oil supply and pressure measurement described later, or offline fixed-point analysis of failure details, stopping rotation after a preset number of rotations to test whether the conduit 600 has failed. Failure detection methods can be macroscopic physical performance monitoring, such as supplying oil to the sealed conduit 600 and measuring oil pressure; microscopic morphology monitoring, such as microscopic or electron microscopic examination of microcracks; or non-destructive testing, such as ultrasonic testing of internal cracks, magnetic particle or penetrant testing of surface cracks, etc. These are standard settings for rotary bending fatigue testing and will not be elaborated upon in this application.
[0038] In one possible implementation, the dial indicator probe is also used to contact the fourth follower 530 to detect the radial offset of the fourth follower 530 along the output shaft 110. Measuring the offset of a slider with a dial indicator is a standard setting and will not be elaborated here. Optionally, the end of the fourth follower 530 extending out of the first guide rail 511 is cylindrical and coaxial with the cylindrical first through hole 551. The first guide mechanism 510 is cylindrical and coaxial with the cylindrical receiving cavity 531. The cylindrical radii of the fourth follower 530 and the first guide mechanism 510 are equal. The probe rotates a certain angle around the radial outer wall of the cylinder of the fourth follower 530 and measures the offset within that arc. If the offset is too high, the position of the fourth follower 530 is adjusted until the offset is acceptable. The fourth follower 530 is reset as much as possible so that the first through hole 551 and the receiving cavity 531 are aligned, facilitating the installation of the conduit 600.
[0039] In one possible implementation, the fourth driving member is a fourth screw 540 with a drive slot 541 at its head; the fourth rotating seat 520 is connected to the output shaft 110 and has a preset cavity 521. The preset cavity 521 has a first opening 522 and a second opening 523 at opposite ends. The head of the fourth screw 540 is located inside the preset cavity 521, and the other end passes through the first opening 522 and is threadedly connected to the fourth driven member 530. A rotational clearance is provided between the fourth screw 540 and the inner wall of the first opening 522. The second opening 523 is positioned opposite the drive slot 541. Viewed along the axial direction of the fourth screw 540, the second opening 523 is located within the closed area of the head, and the drive slot 541 is located within the closed area of the second opening 523. In other words, the drive slot 541 is located within the opening range of the second opening 523, and the outer edge of the head is outside the opening range of the second opening 523. The drive slot 541 is smaller than the second opening 523, allowing the screwdriver to be inserted through the second opening 523 and engaged in the drive slot 541 to drive the fourth screw 540 to rotate. The head is larger than the second opening 523, so it is limited by the side wall forming the second opening 523 and cannot come out of the second opening 523. This prevents the fourth screw 540 from flying out and falling off axially while rotating at high speed with the output shaft 110, thus improving safety.
[0040] In one possible implementation, the fourth rotary seat 520 is connected to the output shaft 110 via a fourth guide mechanism 510. The fourth rotary seat 520 is fixedly connected to the fourth guide mechanism 510 via a fourth screw 540. One end of the fourth screw 540 passes through both the fourth rotary seat 520 and the fourth guide mechanism 510 sequentially, and the fourth screw 540 is threadedly connected to a through-hole in the fourth rotary seat 520 and / or the fourth guide mechanism 510. The location of the through-hole is shown below. Figure 12 , Figure 13 The perforation positions on both sides of the preset cavity 521.
[0041] In one possible implementation, the fourth follower 530 is provided with a receiving cavity 531 with one open end. The receiving cavity 531 matches the conduit 600. One open end of the receiving cavity 531 is arranged opposite to the first through hole 551 along a first straight direction. One axial end of the conduit 600 passes through the first through hole 551 and then enters the receiving cavity 531. The axial end of the conduit 600 is located in the receiving cavity 531. The receiving cavity 531 can be a mounting groove with one open end, or it can be a second through hole with open ends opposite each other.
[0042] In one possible implementation, the loading member 500 further includes a movable screw 570. The fourth guiding mechanism 510 is provided with a first guide rail 511, and the fourth driven member 530 is slidably connected to the first guide rail 511 with the sliding direction consistent with the rotational axis of the driving member. This is an inherent structure of the lead screw linear displacement mechanism and will not be elaborated here. In addition to the first guide rail 511, the fourth guiding mechanism 510 also provides a second guide rail 512. The end of the movable screw 570 opposite to its head passes through the connecting part 550 and the fourth driven member 530 in sequence before entering the second guide rail 512. The movable screw 570 is threadedly connected to the through-hole connecting part 550 and / or the fourth driven member 530. The movable screw 570 is slidably connected to the second guide rail 512, and the sliding direction is consistent with the sliding direction of the fourth driven member 530.
[0043] Optionally, a second slider 513 is provided within the second guide rail 512. The second slider 513 has a second threaded hole that matches the moving screw 570. The end of the moving screw 570 opposite to its head passes through the connecting part 550 and the fourth follower 530 in sequence before entering the second guide rail 512 and threadedly connecting to the second threaded hole. That is, one end of the moving screw 570 is slidably connected to the second guide rail 512 through the second slider 513, and the sliding direction of the second slider 513 within the second guide rail 512 is consistent with the sliding direction of the fourth follower 530 within the fourth guide rail.
[0044] Optionally, the second guide rail 512 is a guide cavity in the shape of a waist-shaped cylinder, with an opening at the bottom surface and the outer edge of the opening coinciding with the outer edge of the bottom surface. It should be noted that the waist-shaped cylinder is a straight cylinder with a waist-shaped bottom and top surface (also called a racetrack shape, oblong hole, etc., a closed planar figure composed of a rectangle and two semicircles of equal radius, where the width of the rectangle is the same as and coincides with the diameter of the semicircles). The second slider 513 is also a waist-shaped cylinder, and the radius of its waist shape matches that of the guide cavity to form a small sliding gap between the second slider 513 and the inner wall of the guide cavity. The longer side of the rectangle in the waist shape of the second slider 513 is smaller than the longer side of the rectangle in the waist shape of the guide cavity; the difference is the maximum sliding distance preset for the guide rail. The second slider 513 slides along the length of the rectangle in the waist shape of the guide cavity.
[0045] The technical features of the above embodiments can be combined in any way (as long as there is no contradiction in the combination of these technical features). For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described; these embodiments not explicitly written should also be considered to be within the scope of this specification.
[0046] The present application has been described in a relatively specific and detailed manner above through general descriptions and specific embodiments. It should be understood that, based on the technical concept of the present application, several conventional adjustments or further innovations can be made to these specific embodiments; however, as long as they do not depart from the technical concept of the present application, the technical solutions obtained by these conventional adjustments or further innovations also fall within the protection scope of the claims of the present application.
Claims
1. A device for testing the fatigue of a duct by rotational bending, characterized in that, include: A rotary driver, the output shaft of which rotates about a first linear axis, the output shaft being equipped with a dial indicator; The mounting part has one end of the conduit connected to the output shaft and the other end of the conduit rotatably connected to the mounting part. The probe of the dial indicator is used to contact the mounting part to detect the radial offset of the mounting part along the output shaft. The support base is provided with a first driving device for driving the mounting part to move radially along the output shaft and to maintain its position after movement; A loading element is used to apply a bending load perpendicular to the first straight line to the conduit; A failure detection device is used to detect the failure characteristics of the catheter and characterize the fatigue failure state of the catheter. A strain measuring device is provided, wherein a strain gauge of the strain measuring device is attached to the outer surface of the conduit, the length direction of the strain gauge is consistent with the axial direction of the conduit, and a gap is provided between the strain gauge and the tubular axis of the conduit along the offset direction of the mounting part.
2. The duct rotational bending fatigue testing device according to claim 1, characterized in that, The failure detection device includes: A fluid supply device, wherein the output end of the fluid supply device is in sealed communication with one axial opening of the conduit mounted on the mounting part, and the other axial end of the conduit is sealed; A pressure monitoring device is used to monitor the fluid pressure at the output end of the fluid supply device.
3. The duct rotational bending fatigue testing device according to claim 1, characterized in that, The first driving device includes a first lead screw linear displacement mechanism. The mounting part is connected to the support base through the first lead screw linear displacement mechanism. The mounting part is connected to the driven member of the first lead screw linear displacement mechanism. The linear displacement direction of the first lead screw linear displacement mechanism is perpendicular to the first straight line.
4. The duct rotational bending fatigue testing device according to claim 3, characterized in that, The first lead screw linear displacement mechanism has a handle at one axial end of its driving lead screw.