Clamp suitable for various pipe diameters and clamping method

Abstract

The invention provides a clamp suitable for various pipe diameters and a clamping method. The clamp comprises a first base with a guide groove, a clamping piece arranged on the first base in a sliding mode, an asynchronous adjusting device, a synchronous adjusting device and a clutch device. Wherein the asynchronous adjusting device and the active adjusting device can adjust the position of the clamping piece, so that the clamp can adapt to tubular workpieces with different pipe diameters; besides, the engagement or disengagement state of the driving gear and the driven gear of the synchronous adjusting device can be switched through the clutch device, so that different clamping pieces can be asynchronously adjusted according to the section shape of the tubular workpiece to be clamped, and the clamp can adapt to the section shape error of the tubular workpiece.

Description

TECHNICAL FIELD

[0001] The application relates to the clamping technical field, in particular to a clamp suitable for various pipe diameters and a clamping method. BACKGROUND

[0002] As a new nuclear power technology, the heat pipe reactor has high flexibility and safety, can be deployed in remote areas or off-grid areas, meets the power demand of the area, and enhances the flexibility of energy distribution. At the same time, compared with traditional coal-fired power plants, the heat pipe reactor almost does not produce greenhouse gases such as carbon dioxide during operation, meets the global emission reduction target and low-carbon economy requirements, and helps to cope with climate change and environmental protection. However, the slender thin-walled pipe structure in the heat pipe reactor has a particularly harsh service environment, usually working in a high-temperature, radiation and high-pressure environment, and the stiffness difference between the two sides of the support structure and the slender thin-walled pipe is large, which is easy to produce local high stress, thereby weakening the service life of the heat pipe reactor. Under high-temperature extreme conditions, the slender thin-walled pipe structure will be subjected to additional axial mechanical load, and the combined action of the axial temperature difference and the high-temperature creep effect will cause creep fracture, creep-ratchet and creep-buckling behaviors in the structure, destroy the stability of the structure, and increase the safety risk of nuclear power facilities. Therefore, the mechanical behavior of the slender thin-walled pipe structure under different extreme conditions has become a research hotspot, and a large number of mechanical experiments have been carried out in various colleges and research institutions to ensure the safety of the heat pipe reactor in service.

[0003] The mechanical testing machine clamp in the related art is designed according to the standard sample, and the slender thin-walled pipe structure is a non-standard sample, so the existing test clamp cannot meet its needs, and the clamp suitable for different pipe diameters becomes the main difficulty in carrying out the mechanical analysis test of the slender thin-walled pipe. SUMMARY

[0004] The application provides a clamp suitable for various pipe diameters and a clamping method, and aims to provide a clamp suitable for different pipe diameters.

[0005] In a first aspect, the application provides a clamp suitable for various pipe diameters, used for clamping a tubular workpiece, comprising: A first base has at least two guide grooves arranged at intervals along a circumference, and the length direction of each guide groove is along the radial direction of the circumference. A clamping mechanism includes a clamping piece slidingly arranged in the guide groove in a one-to-one correspondence, and is used for abutting against the inner wall or the outer wall of the tubular workpiece. An asynchronous adjusting device includes an asynchronous adjusting screw corresponding to the clamping piece in a one-to-one correspondence, and each asynchronous adjusting screw is threadedly connected with the corresponding clamping piece. The synchronous adjusting device comprises a driving gear and a plurality of driven gears corresponding to the asynchronous adjusting lead screws, each of the driven gears is used to drive the corresponding asynchronous adjusting lead screw to rotate, and the driving gear is used to drive all the driven gears to rotate synchronously; The clutching device is used to control the driving gear and the driven gears to switch between the meshing state and the disengaging state.

[0006] In the above technical solution, the asynchronous adjusting device and the driving adjusting device can adjust the positions of the clamping members, so that the clamp can adapt to the tubular workpieces with different diameters. In addition, by setting the clutching device, the meshing or disengaging state of the driving gear and the driven gears can be switched, so that the asynchronous adjustment of different clamping members can be adjusted according to the cross-sectional shape of the tubular workpiece to be clamped, and the clamp can adapt to the cross-sectional shape error of the tubular workpiece.

[0007] In a possible implementation, the driving gear and the driven gears are bevel gears, and all the driven gears are located on the same side of the driving gear and mesh with the driving gear. The driving gear is slidingly arranged on the first base. The clutching device comprises a threaded rod and an elastic member. The threaded rod is threadedly connected to the first base and is used to push the driving gear and the driven gears apart. The elastic member is used to push the driving gear and the driven gears to mesh.

[0008] In a possible implementation, the synchronous adjusting device further comprises a spline, and the spline is rotationally connected to the first base. The driving gear is sleeved on the spline and can slide relative to the spline, and the spline is used to drive the driving gear to rotate.

[0009] In a possible implementation, the clamp further comprises a scale, and the scale is arranged along the length direction of each guide groove.

[0010] In a possible implementation, the clamp further comprises a radial loading device. The radial loading device comprises a second base and a loading platform, the loading platform is slidingly connected to the second base and can slide along the radial direction of the circumference. The loading platform is plug-in connected to the first base and is used to connect with the first base and drive the first base to slide along the radial direction of the circumference.

[0011] In a possible implementation, the radial loading device further comprises a first loading lead screw, and the first loading lead screw is threadedly connected to the loading platform. The first loading screw is used to drive the loading platform to slide along a first direction.

[0012] In one possible implementation, the first loading screw is slidably connected to the second base; The radial loading device further includes a second loading screw, which is slidably connected to the second base and threadedly connected to the loading table. The second loading screw is used to drive the loading platform to slide along the second direction; The first direction is perpendicular to the second direction.

[0013] In one possible implementation, the radial loading device further includes a first follower rack and a first stabilizing gear; the first follower rack is slidably connected to the end of the first loading screw, and the length direction of the first follower rack is along the second direction; the first stabilizing gear is rotatably connected to the second base and meshes with the first follower rack; The radial loading device further includes a second follower rack and a second stabilizing gear; the second follower rack is slidably connected to the end of the second loading screw, and the length direction of the second follower rack is along the first direction; the second stabilizing gear is rotatably connected to the second base and meshes with the second follower rack.

[0014] Secondly, this application provides a clamping method for clamping tubular workpieces, the clamping method comprising the following steps: The shape of the end cross section of the tubular workpiece to be clamped is measured; The clutch control device separates the driving gear from the driven gear, and based on the mapping results, the position of each clamping component is adjusted sequentially using an asynchronous adjustment device; The clutch control device engages the drive gear and driven gear, and the active adjustment device synchronously adjusts the position of all clamping parts until all clamping parts are in contact with the tubular workpiece.

[0015] The fixtures used in the above method, including both asynchronous and active adjustment devices, can adjust the position of the clamping components, thereby enabling the fixture to adapt to tubular workpieces of different diameters. In addition, by setting a clutch device, the meshing or disengaging states of the driving gear and the driven gear can be switched, thereby allowing asynchronous adjustment of different clamping components according to the cross-sectional shape of the tubular workpiece to be clamped, which enables the fixture to adapt to cross-sectional shape errors of the tubular workpiece.

[0016] In one possible implementation, the clamp further includes a radial loading device; the loading platform of the radial loading device is pluggably connected to the first base and is used to connect to the first base and drive the first base to slide radially along the circumference, the method further includes: After all the clamping elements are in contact with the tubular workpiece, the first base is connected to the loading stage. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments of this disclosure, the accompanying drawings used in the embodiments will be briefly described below. These drawings are incorporated in and constitute a part of this specification. They illustrate embodiments conforming to this disclosure and, together with the specification, serve to explain the technical solutions of this disclosure. It should be understood that the following drawings only show some embodiments of this disclosure and should not be considered as limiting the scope. Those skilled in the art can obtain other related drawings based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the overall fixture in the embodiments of this application; Figure 2 This is a cross-sectional view of the fixture in the embodiments of this application; Figure 3 This is a schematic diagram of the internal structure of the fixture in the embodiments of this application; Figure 4 This is a schematic diagram of the clamping member abutting against the inner wall in an embodiment of this application; Figure 5 This is a schematic diagram of the clamping member abutting against the outer wall in an embodiment of this application; Figure 6 This is a schematic diagram of the synchronization adjustment device in the embodiments of this application; Figure 7 This is a schematic diagram of the clutch device in an embodiment of this application; Figure 8 This is one of the schematic diagrams of the radial loading device in the embodiments of this application; Figure 9 This is the second schematic diagram of the radial loading device in the embodiments of this application; Figure 10 This is a schematic diagram of the clamping method in the embodiments of this application. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this application clearer, the application will now be described in further detail with reference to the accompanying drawings.

[0020] It should be noted that, unless otherwise defined, the technical or scientific terms used in one or more embodiments of this specification should have the ordinary meaning understood by one of ordinary skill in the art to which this disclosure pertains. The terms "first," "second," and similar words used in one or more embodiments of this specification do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0021] To facilitate understanding of the fixtures provided in the embodiments of this application, their application scenarios are first described. The fixtures provided in the embodiments of this application are used for clamping tubular workpieces, and are particularly useful for clamping slender, thin-walled tubes for heat pipe nuclear reactors on a test bench.

[0022] As an emerging nuclear power technology, heat pipe reactors offer high flexibility and safety, allowing for deployment in remote or off-grid areas to meet local electricity demands and enhance energy distribution flexibility. Compared to traditional coal-fired power plants, heat pipe reactors produce virtually no greenhouse gases such as carbon dioxide during operation, aligning with global emission reduction targets and low-carbon economic requirements, thus contributing to climate change mitigation and environmental protection. However, the slender, thin-walled tube structure in heat pipe reactors operates under extremely harsh environments, typically involving high temperatures, radiation, and high pressure. The significant stiffness difference between the supporting structures on either side and the slender, thin-walled tubes can easily generate localized high stresses, thereby reducing the lifespan of the heat pipe reactor. Under extreme high-temperature conditions, the slender, thin-walled tube structure experiences additional axial mechanical loads. The combined effect of these loads with axial temperature differences and high-temperature creep effects leads to creep fracture, creep-ratcheting, and creep-buckling behaviors within the structure, compromising structural stability and increasing the safety risks of nuclear power facilities. Therefore, the mechanical behavior of slender thin-walled tube structures under different extreme conditions has become a current research hotspot, and a large number of mechanical experiments have been carried out in various universities and research institutions to ensure the safety of heat pipe reactors in service.

[0023] In related technologies, mechanical testing machine fixtures are mostly designed based on standard specimens. As a non-standard specimen, the existing testing fixtures cannot meet the requirements of slender thin-walled tube structures. Fixtures that can adapt to different tube diameters have become the main difficulty in carrying out mechanical analysis tests on slender thin-walled tubes.

[0024] Based on this, this application provides a clamp and clamping method applicable to multiple pipe diameters, aiming to provide a clamp that can be used for different pipe diameters. First, with reference to the accompanying drawings, the clamp applicable to multiple pipe diameters provided in this application will be described in detail.

[0025] Please refer to the above. Figure 1 and Figure 2 and Figure 3 , Figure 1 This is a schematic diagram of the overall fixture in the embodiments of this application. Figure 2 This is a cross-sectional view of the fixture in the embodiments of this application. Figure 3 This is a schematic diagram of the interior of the fixture in the embodiments of this application.

[0026] The clamping device applicable to various pipe diameters provided in this application includes a clamping mechanism, an asynchronous adjustment device, a synchronous adjustment device, a clutch device, and a first base 1 for supporting the above-mentioned devices. The clamping mechanism is used to clamp and fix the tubular workpiece from its inner or outer wall; the asynchronous and synchronous adjustment devices can be used to adjust the posture of the clamping mechanism to adapt to tubular workpieces of different diameters; and the clutch device is used to switch the posture of the clamping mechanism between the asynchronous and synchronous adjustment devices.

[0027] In the specific configuration of the clamping mechanism, the clamping mechanism includes at least two clamping members 2, which are used to abut against the inner or outer wall of the tubular workpiece. (Reference) Figure 4 , Figure 4 This is a schematic diagram of the clamping member abutting against the inner wall in an embodiment of this application, as shown below. Figure 4 As shown, two or more clamping elements 2 can support the tubular workpiece from the inside out to clamp and fix the tubular workpiece. (Reference) Figure 5 , Figure 5 This is a schematic diagram of the clamping member abutting against the outer wall in an embodiment of this application, as shown below. Figure 5 As shown, two or more clamping members 2 can also clamp the tube wall from the outside to the inside of the tube wall to fix the tube workpiece. These clamping members 2 are slidably disposed on the first base 1, and the position of each clamping member 2 can be adjusted by an asynchronous adjustment device or a synchronous adjustment device so that the fixture can adapt to tube workpieces of different diameters.

[0028] When specifically setting the first base 1, the first base 1 has at least two guide grooves 11 spaced apart along the circumference, and the length direction of each guide groove 11 is along the radial direction of the circumference. Here, the circumference is a virtual circumference introduced to describe the arrangement position of the guide grooves 11, and the straight line in the length direction of each guide groove 11 is a diameter of the circumference.

[0029] The guide groove 11 is used to accommodate the clamping members 2 of the clamping mechanism. Each clamping member 2 is slidably disposed in the guide groove 11 and can slide radially along the circumference under the drive of the asynchronous adjustment device or the synchronous adjustment device.

[0030] The specific number of guide grooves 11 can be two, three, four, five, six, etc., that is, the number of clamping members 2 can also be two, three, four, five, six, etc. It should be noted that, in order for the clamping members 2 to stably clamp the workpiece, when there are two guide grooves 11, the central angle between the straight lines containing the length directions of the two guide grooves 11 should be 180 degrees; when there are more than two guide grooves 11, at least one guide groove 11 should not be within the same semicircle as other guide grooves 11. Furthermore, when specifically setting the guide grooves 11, the guide grooves 11 can be evenly spaced or unevenly spaced. As an example, such as... Figure 1 The fixture shown includes six evenly spaced guide grooves 11.

[0031] In the specific configuration of the asynchronous adjustment device, the asynchronous adjustment device includes asynchronous adjustment screws 3 corresponding one-to-one with the clamping members 2, and each asynchronous adjustment screw 3 is threadedly connected to the corresponding clamping member 2. The length direction of the asynchronous adjustment screw 3 is also arranged radially along the circumference, and the asynchronous adjustment screw 3 is rotatably connected to the first base 1. With this configuration, the corresponding clamping member 2 can be moved closer to or further away from the circumference radially by rotating the asynchronous adjustment screw 3, thus allowing individual adjustment of a single clamping member 2 by rotating the asynchronous adjustment screw 3.

[0032] The synchronization adjustment device can be used to synchronize all clamping components 2, that is, to drive all clamping components 2 to slide synchronously in a centrifugal or centrifugal manner. Specifically, the synchronization adjustment device includes a driving gear 41 and driven gears 42 corresponding one-to-one with the asynchronous adjusting screw 3. Each driven gear 42 is used to drive the corresponding asynchronous adjusting screw 3 to rotate. Each driven gear 42 is connected to the asynchronous adjusting screw 3. The rotation of the driven gear 42 drives the corresponding asynchronous adjusting screw 3 to rotate, thereby driving the clamping component 2 to slide synchronously in a centrifugal or centrifugal manner. The driving gear 41 is used to drive all the synchronization gears to rotate synchronously. That is, each driven gear 42 meshes with the driving gear 41. In this way, the rotation of the driving gear 41 drives all the driven gears 42 to rotate simultaneously, thereby realizing the indirect driving of all clamping components 2 to slide synchronously in a centrifugal or centrifugal manner using the synchronization adjustment device. By setting up a synchronous adjustment device to adjust all clamping parts 2 synchronously, the clamping operation efficiency can be improved; at the same time, it is also convenient to balance the magnitude of the contact force between multiple clamping parts 2 and the closing, reducing the risk that the contact force between a certain clamping part 2 and the pipe wall is too large or too small; and, the synchronous clamping of the workpiece by all clamping parts 2 can also reduce the risk of workpiece deformation during the clamping process.

[0033] The clutch device controls the switching between the engagement and disengagement states of the driving gear 41 and the driven gear 42. Specifically, the clutch device can be in either an engaged or disengaged state. When the clutch device is in the engaged state, the driving gear 41 is engaged with all the driven gears 42. Rotating the driving gear 41 synchronously drives all the clamping members 2 to slide in a radial or eccentric manner, thereby synchronously driving the clamping members 2. When the clutch device is in the disengaged state, the driving gear 41 is disengaged from all the driven gears 42. At this time, rotating a single asynchronous adjusting screw 3 drives a single clamping member 2 to slide in a radial or eccentric manner, thereby individually adjusting the clamping member 2.

[0034] By setting up a clutch device, the meshing and disengagement states of the driving gear 41 and the driven gear 42 can be easily switched, thereby effectively reducing the adverse effects of cross-sectional roundness defects of the workpiece to be clamped on clamping stability and experimental results.

[0035] Please refer to the above. Figure 6 , Figure 6 This is a schematic diagram of the synchronization adjustment device in the embodiments of this application.

[0036] As an optional implementation, both the driving gear 41 and the driven gear 42 are bevel gears, with all driven gears 42 located on the same side of the driving gear 41 and meshing with it; and the driving gear 41 is slidably mounted on the first base 1. Specifically, the driven gear 42 is disposed on the side of the driving gear 41 with the annular rack, and the driving and driven gears can slide relative to the first base 1 along the axial direction of the driving gear 41. This sliding connection can be achieved by slidably mounting the driving gear 41 onto a gear shaft, etc. In this configuration, a clutch device can be provided to control the driving gear 41 to slide axially away from or towards the driving gear.

[0037] Please refer to the above. Figure 7 , Figure 7 This is a schematic diagram of the clutch device in an embodiment of this application.

[0038] Optionally, the clutch device includes a threaded rod 51 and an elastic element 52. The threaded rod 51 is disposed on the side of the driving gear 41 near the driven gear and is threadedly connected to the first base 1. The elastic element 52 is disposed on the side of the driving gear 41 away from the driven gear and abuts against the driving gear 41. By rotating the threaded rod 51, the threaded rod 51 can push the driving gear 41 to slide in the direction away from the driven gear 42, thereby separating the driving gear 41 from the driven gear 42, that is, realizing the disengaged state of the clutch device. The elastic element 52 can be a spring, elastic plunger, etc. The elastic element 52 applies a spring force to the driving gear 41 toward the driven gear 42, so that when the threaded rod 51 is rotated in the opposite direction, the driving gear 41 can slide toward the driven gear 42 under the push of the elastic element 52 until the driving gear 41 and the driven gear 42 are engaged, that is, realizing the engaged state of the clutch device.

[0039] The bevel gears configured in this way, serving as the driving gear 41 and driven gear 42, can convert the rotational motion of the driving gear 41 into the synchronous rotation of multiple lead screws, and can save the arrangement space of the driving gear 41 and driven gear 42. In addition, the threaded rod 51 and the elastic element 52 serve as a clutch device, realizing the technical solution of switching between the meshing state and the disengagement state between the driving gear 41 and driven gear 42. This solution has the advantages of simple and compact structure and easy adjustment and switching of clutch state.

[0040] As an optional implementation, the synchronization adjustment device further includes a spline 43, which is rotatably connected to the first base 1. A drive gear 41 is fitted onto the spline 43 and can slide relative to it. The spline 43 drives the drive gear 41 to rotate. Specifically, the spline 43 acts as a gear shaft for the drive gear 41, and the spline 43 meshes with the drive gear 41. When the clutch is engaged, rotating the spline 43 drives the gear shaft to rotate, thereby driving all clamping members 2 to move synchronously in a centripetal or centrifugal motion.

[0041] When using the fixture, the cross-section of the workpiece to be clamped can be measured first. If the cross-section is a standard circle with good roundness, all clamping parts 2 can be adjusted synchronously to slide in a centripetal or centrifugal manner through the synchronous adjustment device to clamp the workpiece. All clamping parts 2 can slide in a centripetal or centrifugal manner, so the fixture can be adapted to tubular workpieces of various diameters by adjusting the position of the clamping parts 2.

[0042] If the measurement reveals a non-negligible roundness defect in the cross-section, the clutch can be disengaged first, and the position of each clamping element 2 can be adjusted to accommodate the roundness defect. Then, the clutch is switched to engagement, and the drive gear 41 is rotated to allow all clamping elements 2 to slide synchronously in a centripetal or centrifugal manner, thus clamping the workpiece. By adjusting the position of each clamping element 2 in this way, even when the roundness of the tubular workpiece's cross-section has a large error, each clamping element 2 can still abut against the tube wall with a relatively uniform force, which helps maintain the original roundness defect of the tube wall. This allows for a more realistic test of the tubular workpiece's performance in experiments.

[0043] As an optional implementation, the fixture also includes a scale 7, which is set along the length of each guide groove 11. The scale 7 can be specifically set on one or both sides of the guide groove 11. When it is necessary to adjust the position of a single clamping member 2 individually according to the measurement results, the scale 7 can quickly indicate the adjustment distance of the clamping member 2, thereby improving the operating efficiency.

[0044] When setting the scale 7, scale 7 can be set on both sides of each guide groove 11; or the scale 7 can be rotatably connected to the first base 1, so that one scale 7 can mark two or more guide grooves 11 by rotating.

[0045] In the case where scales 7 are provided on both sides of each guide groove 11, scales 7 can be separate components and fixed to the first base 1 by means of bonding, welding, riveting, etc.; of course, in some embodiments, scales 7 can also be directly integrally formed and set on the first base 1 by means of engraving, spraying, etc.

[0046] In the specific configuration of the first base 1, the first base 1 can be in the form of a shell, with a first receiving space enclosed inside the shell. The asynchronous adjustment device, the synchronous adjustment device, and the clutch device are all housed within the first receiving space. Part of the clamping member 2 is located within the first receiving space and connected to the asynchronous adjustment lead screw 3. Part of the clamping member 2 extends out of the first receiving space through the guide groove 11 to abut against the tube wall of the tubular workpiece. In addition, a series of through holes can be opened on the shell. These through holes correspond to the end of the asynchronous adjustment lead screw 3, the spline 43 of the synchronous adjustment device, and the threaded rod 51 of the clutch device, respectively. Thus, these through holes allow the user to easily rotate these components using tools or by directly driving them.

[0047] Optionally, the same meshing part can be provided at the end of the asynchronous adjusting screw 3, the end of the threaded rod 51, and the end of the spline 43. This allows the user to easily rotate the asynchronous adjusting screw 3, the threaded rod 51, and the spline 43 using the same universal tool 8. Here, the universal tool 8 can refer to a general-purpose screwdriver or a specific rotating rod, etc.

[0048] In summary, in the synchronous adjustment device provided by this application, both the asynchronous adjustment device and the active adjustment device can adjust the position of the clamping member 2, so that the fixture can adapt to tubular workpieces of different diameters; in addition, by setting a clutch device, the meshing or disengaging states of the driving gear 41 and the driven gear 42 can be switched, so that the different clamping members 2 can be asynchronously adjusted according to the cross-sectional shape of the tubular workpiece to be clamped, so that the fixture can adapt to the cross-sectional shape error of the tubular workpiece.

[0049] As an optional implementation, the fixture provided in this application embodiment further includes a radial loading device for applying a radial load to the end of the tubular workpiece. Specifically, the radial loading device includes a second base 61 and a loading platform 62. The loading platform 62 is slidably connected to the second base 61 and can slide radially along the circumference. The loading platform 62 is also used for plugging and unplugging connection with the first base 1 and for connecting to the first base 1 and driving the first base 1 to slide radially along the circumference.

[0050] The second base 61 is fixedly connected to the test bench. The loading platform 62 can be slidably connected to the second base 61 via a slide rail, rack and pinion, or similar means. When an appropriate driving force is applied to the loading platform 62, the user can drive it to slide in at least one radial direction along the circumference. Simultaneously, the loading platform 62 also supports the first base 1. Specifically, the loading platform 62 and the first base 1 can be plugged in and out using pins, clips, or similar means, and the loading platform 62 and the first base 1 are detachable. It should be understood that this plugging and unplugging connection can be made from any direction, but regardless of the plugging and unplugging method, it must be ensured that when the loading platform 62 slides radially along the circumference, it can drive the second base 61 to slide together.

[0051] When using the clamping fixture, the tubular workpiece can be placed on the first base 1 in advance. After the clamping mechanism has clamped the tubular workpiece, the tubular workpiece and the first base 1 can be placed together on the second base 61.

[0052] By setting the loading stage 62, the first base 1 can be driven to slide radially, that is, the loading stage 62 can drive the clamped end of the tubular workpiece to slide radially, which can facilitate the application of radial load to the tubular workpiece in experiments. In addition, for tubular workpieces, in addition to the roundness error of the cross section, there is also the coaxiality error in its length direction; the loading stage 62 driving the first base 1 to slide radially can also eliminate the coaxiality error of the tubular workpiece within a certain range.

[0053] Please refer to the above. Figure 8 , Figure 8 This is one of the schematic diagrams of the radial loading device in the embodiments of this application.

[0054] As an optional implementation, the radial loading device further includes a first loading screw 63, which is threadedly connected to the loading table 62; by rotating the first loading screw 63, the first loading screw 63 can drive the loading table 62 to slide along a first direction, wherein the first direction is the length direction of the first loading screw 63.

[0055] By setting a first lead screw and using the first lead screw to drive the loading table 62 to slide radially along the circumference, radial loading of tubular workpieces or correction of the coaxiality of tubular workpieces can be performed conveniently and quickly.

[0056] Please refer to the above. Figure 9 , Figure 9 This is the second schematic diagram of the radial loading device in the embodiments of this application.

[0057] As an optional implementation, the first loading screw 63 is slidably connected to the second base 61, and the radial loading device also includes a second loading screw 66 slidably connected to the second base 61. The second loading screw 66 is threadedly connected to the loading table 62. By rotating the second loading screw 66, the loading table 62 can be driven to slide along a second direction. The first direction is perpendicular to the second direction.

[0058] The first loading screw 63 can drive the loading platform 62 to slide in the first direction, while the second loading screw 66 can follow the loading platform 62 to slide relative to the second base 61 in the first direction; the second loading screw 66 can drive the loading platform 62 to slide in the second direction, while the first loading screw 63 can follow the loading platform 62 to slide relative to the second base 61 in the second direction.

[0059] By setting the second loading screw 66, the loading table 62 can slide in two directions, thereby improving the flexibility of the fixture in applying radial loading force to the tubular workpiece. In addition, the first loading screw 63 and the second loading screw 66, while driving the loading table 62 to slide in the second direction, also serve to slide the loading table 62 to the second base 61, thereby achieving the purpose of simplifying the mechanism.

[0060] As an optional implementation, the radial loading device further includes a first follower rack 64 and a first stabilizing gear 65; the first follower rack 64 is slidably connected to the end of the first loading screw 63, and the length direction of the first follower rack 64 is along the second direction; the first stabilizing gear 65 is rotatably connected to the second base 61 and meshes with the first follower rack 64.

[0061] The first loading screw 63 has two ends in a first direction. A first follower rack 64 can be disposed at one of the two ends, or it can be disposed at each of the two ends. The number of first stabilizing gears 65 corresponding to each first follower rack 64 can be one, two, or more, and these first stabilizing gears 65 can be disposed on one side or both sides of the first follower rack 64. As an example, such as... Figure 9 The radial loading device shown has a first follower rack 64 at both ends of the first loading screw 63, and two first stabilizing gears 65 are respectively provided on both sides of each first follower rack 64.

[0062] As the first loading screw 63 slides along the second direction with the loading platform 62, the first follower rack 64 also slides along the second direction with the first loading screw 63. Under the constraint of the first stabilizing gear 65, the first follower rack 64 can only slide along the second direction. By setting the first follower rack 64 and the first stabilizing gear 65, the first loading screw 63 can be stabilized, and the risk of wobbling during its sliding along the second direction can be reduced.

[0063] The radial loading device also includes a second follower rack 67 and a second stabilizing gear 68; the second follower rack 67 is slidably connected to the end of the second loading screw 66, and the length direction of the second follower rack 67 is along the first direction; the second stabilizing gear 68 is rotatably connected to the second base 61 and meshes with the second follower rack 67.

[0064] The second loading screw 66 has two ends in the second direction. The second follower rack 67 can be located at one of the two ends, or it can be located at each of the two ends. The number of second stabilizing gears 68 corresponding to each second follower rack 67 can be one, two, or more, and these second stabilizing gears 68 can be located on one side or both sides of the second follower rack 67. As an example, such as... Figure 9 The radial loading device shown has a second follower rack 67 at both ends of the second loading screw 66, and two second stabilizing gears 68 are respectively provided on both sides of each second follower rack 67.

[0065] As the second loading screw 66 slides along the first direction with the loading platform 62, the second follower rack 67 also slides along the first direction with the second loading screw 66. However, due to the constraint of the second stabilizing gear 68, the second follower rack 67 can only slide along the first direction. By setting the second follower rack 67 and the second stabilizing gear 68, the second loading screw 66 can be stabilized, and the risk of wobbling during its sliding along the first direction can be reduced.

[0066] Optionally, when specifically configuring the loading stage 62 and the first base 1 for plug-in connection, a pin can be used for connection. See also... Figure 2 and Figure 9 In a specific example, a pin 12 is provided on the first base 1, and a pin hole 621 is provided on the loading stage 62. The pin 12 can be inserted into the pin hole 621 to realize the plug-in connection between the loading stage 62 and the first base 1.

[0067] Optionally, when specifically configuring the second base 61, the second base 61 can also be presented as a shell, with a second receiving space enclosed inside the shell. The first loading screw 63, the second loading screw 66, the first follower rack 64, the second follower rack 67, the first stabilizing gear 65, and the second stabilizing gear 68 are all accommodated in the second receiving space. The shell has an opening that allows the loading platform 62 to be exposed and slide along the first and second directions. Part of the loading platform 62 is located in the second receiving space and connected to the first loading screw 63 and the second loading screw 66, while part of the loading platform 62 is exposed through the opening to the second base 61 and is used for plugging and unplugging connection with the first base 1.

[0068] Alternatively, a series of through holes can be made on the housing, which can correspond to the first loading screw 63 and the second loading screw 66 respectively. Thus, through these through holes, the user can easily use tools or directly drive the first loading screw 63 or the second loading screw 66 to rotate.

[0069] Optionally, the ends of the first loading screw 63 and the second loading screw 66 may also be provided with the same meshing parts as the ends of the asynchronous adjusting screw 3, the threaded rod 51 and the spline 43, so that the user can use the same general-purpose tool 8 to rotate the asynchronous adjusting screw 3, the threaded rod 51, the spline 43, the first loading screw 63 and the second loading screw 66.

[0070] Optionally, in order to reduce rotational resistance and improve rotational smoothness, bearing connections are used when the asynchronous adjusting screw 3 and spline 43 are rotatably connected to the first base 1, and when the first stabilizing gear 65 and the second stabilizing gear 68 are rotatably connected to the second base 61.

[0071] Please refer to the above. Figures 1-9 as well as Figure 10 , Figure 10 This is a schematic diagram of the clamping method in the embodiments of this application.

[0072] This application also provides a clamping method for clamping tubular workpieces, wherein any of the clamps described above is used during the clamping process. The clamping method includes the following steps: S01, the end cross-sectional shape of the tubular workpiece to be clamped is measured.

[0073] Specifically, through surveying, the end cross-sectional dimensions and roundness information of the tubular workpiece to be clamped can be obtained, and the size and location of roundness defects in the tubular workpiece can be determined.

[0074] S02, control the clutch device to separate the driving gear from the driven gear, and based on the mapping results, use the asynchronous adjustment device to adjust the position of each clamping component in sequence.

[0075] Specifically, in this step, after the control gear separates from the driven gear, the position of each clamping element can be adjusted individually.

[0076] During the surveying process, the position of each clamping component that abuts against the pipe wall can be planned in advance. This allows us to know the distance from the center of the virtual circumference when each clamping component is pressed against the pipe wall under ideal conditions. The position of each clamping component can then be adjusted based on this center distance.

[0077] In the specific adjustment process, when the driving gear and driven gear are meshing, all clamping parts can be slid simultaneously to a standard circumference of a suitable diameter, either centrifugally or centrifugally. Then, the position of each clamping part relative to the standard circumference can be adjusted according to the center distance of each clamping part obtained by measurement. This can make the shape formed by the clamping parts after adjustment similar to the cross-sectional shape of the tubular workpiece obtained by measurement.

[0078] This adjustment process ensures that the clamping force of each clamp is relatively balanced when all clamps slide and press against the pipe wall simultaneously, thereby reducing the risk of uneven clamping force caused by defects in the roundness of the pipe cross section.

[0079] S03, control the clutch device to make the driving gear mesh with the driven gear, and use the active adjustment device to synchronously adjust the position of all clamping parts until all clamping parts are pressed against the tubular workpiece.

[0080] In step S02, if it is necessary to clamp the outer wall of the tubular workpiece, the clamping parts can be slid simultaneously to a standard circumference with a diameter larger than that of the tubular workpiece. After adjusting the position of each clamping part, the driving gear and the driven gear are engaged when controlling the clutch device, and then all clamping parts are driven to slide to the center until all clamping parts are pressed against the outer wall of the tubular workpiece.

[0081] In step S02, if it is necessary to clamp the inner wall of the tubular workpiece, the clamping parts can be slid simultaneously to a standard circumference with a diameter smaller than that of the tubular workpiece. After adjusting the position of each clamping part, the driving gear and the driven gear are engaged when controlling the clutch device, and then all clamping parts are driven to slide centrifugally until all clamping parts are pressed against the inner wall of the tubular workpiece.

[0082] The fixtures used in the above method, including both asynchronous and active adjustment devices, can adjust the position of the clamping components, allowing the fixture to adapt to tubular workpieces of different diameters. Furthermore, by incorporating a clutch device, the engagement or disengagement of the driving and driven gears can be switched, enabling asynchronous adjustment of different clamping components according to the cross-sectional shape of the tubular workpiece to be clamped, thus accommodating cross-sectional shape errors in the workpiece. Additionally, this clamping method utilizes a clutch device to adjust the position of individual clamping components based on roundness defects in the tubular workpiece, thereby achieving precise clamping of the tubular workpiece.

[0083] As an optional implementation, the fixture further includes a radial loading device; the radial loading device includes a second base and a loading platform, the loading platform being slidably connected to the second base and capable of sliding radially along the circumference; the loading platform is pluggably connected to the first base and is used to connect to the first base and drive the first base to slide radially along the circumference. A detailed description of the loading device can be found above and will not be repeated here.

[0084] The method also includes: S04, after all clamping parts are in contact with the tubular workpiece, connect the first base to the loading stage. Once connected, the loading stage allows the first base to slide radially along its circumference. The loading stage can drive the clamped end of the tubular workpiece to slide radially, facilitating the application of radial loads to the workpiece during experiments. Furthermore, for tubular workpieces, in addition to the roundness error of the cross-section, there is also a coaxiality error along its length; the radial sliding of the first base by the loading stage can also eliminate the coaxiality error of the tubular workpiece within a certain range.

[0085] One or more embodiments of this specification are intended to cover all such substitutions, modifications, and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of one or more embodiments of this specification should be included within the scope of protection of this disclosure.

[0086] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A clamp applicable to various pipe diameters for clamping tubular workpieces, characterized in that, The clamp comprises: a first base, which has at least two guide grooves arranged along a circumference at intervals, and each guide groove has a length direction along a radial direction of the circumference; a clamping mechanism, which comprises a clamping piece slidingly arranged in each guide groove and used for abutting against an inner wall or an outer wall of the tubular workpiece; an asynchronous adjusting device, which comprises an asynchronous adjusting screw corresponding to each clamping piece, and each asynchronous adjusting screw is threadedly connected with the corresponding clamping piece; a synchronous adjusting device, which comprises a driving gear and a driven gear corresponding to each asynchronous adjusting screw, each driven gear is used for driving the corresponding asynchronous adjusting screw to rotate, and the driving gear is used for driving all the driven gears to rotate synchronously; a clutching device, which is used for controlling the driving gear and the driven gears to switch between a meshing state and a separation state.

2. The clamp of claim 1, wherein The driving gear and the driven gears are bevel gears, all the driven gears are located on the same side of the driving gear and mesh with the driving gear; the driving gear is slidingly arranged on the first base; the clutching device comprises a threaded rod and an elastic piece; the threaded rod is threadedly connected with the first base and used for driving the driving gear and the driven gears to separate; the elastic piece is used for driving the driving gear and the driven gears to mesh.

3. The clamp of claim 2, wherein The synchronous adjusting device further comprises a spline, which is rotationally connected with the first base; the driving gear is sleeved on the spline and can slide relative to the spline, and the spline is used for driving the driving gear to rotate.

4. The clamp of claim 1, wherein The clamp further comprises a scale, which is arranged along the length direction of each guide groove.

5. The clamp of any one of claims 1 to 4, wherein The clamp further comprises a radial loading device; the radial loading device comprises a second base and a loading table, the loading table is slidingly connected with the second base and can slide along the radial direction of the circumference; the loading table is plug-in connected with the first base and used for connecting with the first base and driving the first base to slide along the radial direction of the circumference.

6. The clamp of claim 5, wherein The radial loading device further comprises a first loading screw, which is threadedly connected with the loading table; the first loading screw is used for driving the loading table to slide in a first direction.

7. The clamp of claim 6, wherein The first loading screw is slidingly connected with the second base; the radial loading device further comprises a second loading screw, which is slidingly connected with the second base and threadedly connected with the loading table; the second loading screw is used for driving the loading table to slide in a second direction; the first direction is perpendicular to the second direction.

8. The clamp of claim 7, wherein, The radial loading device further comprises a first follow-up rack and a first stabilizing gear; the first follow-up rack is slidingly connected at an end of the first loading screw, and the length direction of the first follow-up rack is along the second direction; the first stabilizing gear is rotationally connected with the second base and meshes with the first follow-up rack; the radial loading device further comprises a second follow-up rack and a second stabilizing gear; the second follow-up rack is slidingly connected at an end of the second loading screw, and the length direction of the second follow-up rack is along the first direction; the second stabilizing gear is rotationally connected with the second base and meshes with the second follow-up rack.

9. A clamping method for clamping a tubular workpiece, characterized in that, The clamping method comprises the following steps: Mapping the end cross-sectional shape of the tubular workpiece to be clamped; Controlling the clutching device to separate the driving gear from the driven gear, adjusting the position of each clamping piece in sequence based on the mapping result by using the asynchronous adjusting device; Controlling the clutching device to engage the driving gear with the driven gear, and synchronously adjusting the position of all clamping pieces by using the driving adjusting device until all clamping pieces are in abutment with the tubular workpiece.

10. The method of claim 9, wherein, In the case where the clamp further comprises a radial loading device, the loading platform of the radial loading device is plug-connected with the first base, and is used to connect with the first base and drive the first base to slide along the radial direction of the circumference, the method further comprises: After all clamping pieces are in abutment with the tubular workpiece, connecting the first base to the loading platform.

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