Clamping tool and posture adjusting method

Abstract

The application provides a clamping tool and a posture adjusting method, and relates to the technical field of assembly, to solve the technical problem that there is no effective clamping tool for large cylindrical workpieces to obtain adjustment of different direction freedom. The clamping tool comprises a rack, a pitch structure, at least one limiting structure and at least one clamping structure arranged on the rack; the limiting structure is arranged at a position close to the end of the rack, and is used for fixing the end of the workpiece; each clamping structure comprises a support and a clamping ring rotatably arranged on the support, the clamping ring is a fan ring, and the clamping ring is used for fixing the middle part of the workpiece; the pitch structure comprises a first support, a second support and a first driving mechanism arranged on the second support, the first support is hinged to the rack, the first driving mechanism is drivingly connected to the rack, and the first driving mechanism is used for driving the rack to rotate around the first support. The clamping tool of the application is used for clamping large cylindrical workpieces, can meet the adjustment of different direction freedom in the workpiece machining process, and the posture adjusting process is simple.

Description

Technical Field

[0001] This invention relates to the field of assembly technology, and in particular to a clamping fixture and posture adjustment method. Background Technology

[0002] Generally, large cylindrical workpieces refer to those with a length-to-diameter ratio greater than 8. For such cylindrical workpieces with a large length span, the machined surface is curved, requiring adjustment in different directions. Maintaining workpiece stability is crucial during clamping.

[0003] In related technologies, the clamping fixture structure for large cylindrical workpieces cannot meet the adjustment of the fixture's degrees of freedom in different directions. Summary of the Invention

[0004] The purpose of this invention is to provide a clamping fixture and posture adjustment method to solve the technical problem of large cylindrical workpieces lacking effective clamping fixtures to obtain adjustments with different degrees of freedom in different directions.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] In a first aspect, the present invention provides a clamping fixture for clamping large cylindrical workpieces, the fixture comprising a frame, a pitching structure, at least one limiting structure, and at least one snap-fit ​​structure disposed on the frame.

[0007] The limiting structure is located near the end of the frame and is used to fix the end of the workpiece.

[0008] Each of the snap-fit ​​structures includes a support and a snap ring rotatably disposed on the support, the snap ring being a fan ring, the snap ring being used to fix the middle part of the workpiece;

[0009] The pitch structure includes a first support, a second support, and a first drive mechanism located on the second support. The first support is hinged to the frame, the first drive mechanism is driven to the frame, and the first drive mechanism is used to drive the frame to rotate around the first support.

[0010] According to at least one embodiment of the present invention, the tooling includes a plurality of said snap-fit ​​structures, each of said snap-fit ​​structures being distributed along a first direction, the first direction being the length direction of the frame.

[0011] According to at least one embodiment of the present invention, each of the retaining rings has a rack on its outer side, the rack being located at the middle portion of the retaining ring, and each of the supports has a gear that meshes with the corresponding rack.

[0012] According to at least one embodiment of the present invention, each of the plurality of said supports is fixedly disposed on the frame;

[0013] The gears in each of the supports are connected by a transmission shaft coaxial with the axis.

[0014] According to at least one embodiment of the present application, a part of the supports are slidingly arranged along the first direction on the frame, and the other part of the supports are fixedly arranged on the frame.

[0015] The gears in each of the supports fixedly arranged on the frame are connected by a transmission shaft coaxial with the axis.

[0016] According to at least one embodiment of the present application, the end of each clamping ring is provided with a clamping portion, and each clamping portion at the end of the clamping ring is slidingly arranged on the clamping ring along the radial direction of the clamping ring; and / or,

[0017] The middle part of each clamping ring is provided with at least one clamping portion, and each clamping portion at the middle part of the clamping ring is fixedly arranged on the inner side of the clamping ring.

[0018] According to at least one embodiment of the present application, the clamping portion comprises a resilient pad for abutting against the surface of the workpiece.

[0019] According to at least one embodiment of the present application, the clamping portion comprises a pad, a plurality of protrusions, and an abutting portion corresponding to each protrusion, the plurality of protrusions are uniformly distributed on the surface of the pad, and each abutting portion is located at the end of the corresponding protrusion away from the pad.

[0020] The plurality of abutting portions are used to match and abut against the surface of the workpiece.

[0021] The protrusions are located within the surface of the pad.

[0022] The pad, the protrusions, and the abutting portions are all members made of elastic material.

[0023] According to at least one embodiment of the present application, the end of each clamping ring is further provided with a second driving mechanism, and the second driving mechanism is in transmission connection with the first clamping portion.

[0024] According to at least one embodiment of the present application, the first driving mechanism comprises a linear driving mechanism, one end of the linear driving mechanism is hinged to the side of the second support facing the first support, and the other end of the linear driving mechanism is hinged to the frame.

[0025] According to at least one embodiment of the present application, the linear driving mechanism is one of an electric cylinder, a pneumatic cylinder, or a hydraulic cylinder.

[0026] When the linear driving mechanism is an electric cylinder, the number of the electric cylinders is two, and the two electric cylinders are respectively located at the bottom regions of the rack near the side edges;

[0027] The first driving mechanism further comprises a motor, which is located at the middle part between the two electric cylinders and is in driving connection with the two electric cylinders respectively.

[0028] According to at least one embodiment of the present application, the limiting structure comprises a clamping plate and a clamping device slidably arranged on the rack, and the clamping plate is slidably arranged on the side of the clamping device facing the workpiece;

[0029] The sliding direction of the clamping device on the rack and the sliding direction of the clamping plate on the clamping device are both the first direction;

[0030] The clamping plate is used to fit on one end of the workpiece.

[0031] According to at least one embodiment of the present application, the clamping device comprises a sliding plate and a lifting mechanism arranged on the sliding plate, and the sliding plate is slidably arranged on the rack;

[0032] The lifting mechanism comprises a base and a lead screw connected to the bottom of the base, the lead screw is movably arranged on the sliding plate, and the clamping plate is slidably arranged on the side of the base facing the workpiece;

[0033] The lifting mechanism further comprises a third driving mechanism, and the third driving mechanism is in driving connection with the lead screw.

[0034] According to at least one embodiment of the present application, the tooling further comprises two laser scanners, one of which is located on the ground and the other of which is located on the rack;

[0035] When the rack is in a horizontal state, the two laser scanners are located on the same horizontal plane.

[0036] In the second aspect, the present application further provides a workpiece posture adjusting method, the workpiece is a large cylindrical workpiece, and the tooling of the first aspect is used for adjusting the posture, and the method comprises the following steps:

[0037] Lifting the workpiece to a mounting position, and clamping the workpiece by the clamping structures fixed on the rack;

[0038] Positioning and clamping the workpiece by the clamping structures slidably arranged on the rack;

[0039] Positioning and fixing the limiting structures on both ends of the workpiece respectively;

[0040] Obtain the position information of the workpiece, and adjust the pitch angle and rotation angle of the workpiece around the axis.

[0041] In a second aspect, the application further provides a clamping assembly, comprising the clamping tool and an air bag, wherein the air bag is used for filling the cavity of the workpiece to support the inner wall of the workpiece.

[0042] In one or more of the technical solutions provided in the exemplary embodiments of the application, at least one of the following beneficial effects can be achieved.

[0043] The clamping tool for large cylindrical workpieces in the exemplary embodiments of the application can fix the middle part of the workpiece through the clamping ring of the at least one clamping structure, and the clamping ring can rotate along the support, i.e., the rack, so that the cylindrical workpiece can be adjusted in the angle of rotation around the axis by rotating the clamping ring. The at least one limiting structure is arranged at the end of the workpiece to prevent the workpiece from sliding along the axis. Based on this, the workpiece can be stably fixed on the rack through the cooperation of the clamping structure and the limiting structure.

[0044] Further, the pitch structure comprises a first support, a second support and a first driving mechanism arranged at the second support. The first driving mechanism can drive the rack to rotate around the hinge joint between the first support and the rack, i.e., to adjust the pitch angle of the workpiece. Due to the cooperation between the limiting structure and the clamping structure, even if the pitch angle of the workpiece changes, the workpiece will not slip with the clamping tool, which has stability. Compared with the clamping tool in the prior art, the tool in the exemplary embodiments of the application can not only satisfy the adjustment of the freedom in different directions during the workpiece processing, but also has a simple tool structure, a simple whole posture adjustment process and improved stability, so that the large workpiece is less likely to be deformed. BRIEF DESCRIPTION OF DRAWINGS

[0045] The accompanying drawings illustrate exemplary embodiments of the application and, together with the general description of the application given above, and the detailed description of the embodiments given below, serve to explain the principles of the application. These drawings are included herewith and constitute a part of this specification;

[0046] Figure 1 is a structural schematic diagram of a clamping tool according to an embodiment of the application;

[0047] Figure 2 is a schematic diagram of a clamping structure according to an embodiment of the application;

[0048] Figure 3 is a schematic diagram of a clamping ring structure according to an embodiment of the application;

[0049] Figure 4This is a schematic diagram of a support structure according to an embodiment of the present invention;

[0050] Figure 5 This is a schematic diagram of the second support and the first drive mechanism according to an embodiment of the present invention;

[0051] Figure 6 This is a schematic diagram of the first support structure according to an embodiment of the present invention;

[0052] Figure 7 This is a schematic diagram of the limiting structure according to an embodiment of the present invention;

[0053] Figure 8 This is a schematic diagram of a limiting structure according to another embodiment of the present invention;

[0054] Figure 9 This is a schematic diagram of a limiting structure according to another embodiment of the present invention from another perspective;

[0055] Figure 10 This is a schematic diagram of the frame structure according to an embodiment of the present invention.

[0056] Reference numerals: 10, frame; 11, first slide rail; 12, second slide rail; 13, third slide rail; 20, snap-fit ​​structure; 21, snap ring; 211, rack; 22, support; 221, drive shaft; 222, gear; 23, clamping part; 231, pad; 232, protrusion; 233, fitting part; 24, second drive mechanism; 30, limiting structure; 31, clamping plate; 32, clamping device; 321, base; 322, sliding plate; 323, third drive mechanism; 324, lead screw; 41, first bracket; 42, second bracket; 43, electric cylinder; 44, motor. Detailed Implementation

[0057] To make the technical problems to be solved, the technical solutions, and the beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.

[0058] For large cylindrical workpieces, multiple degrees of freedom of orientation adjustment are required during machining to meet process requirements. Due to the considerable length of these workpieces, improper selection of clamping support points can generate additional stress, causing significant deformation of the workpiece wall. Therefore, a clamping fixture is needed that minimizes workpiece deformation during clamping while ensuring the reliability and stability of the workpiece clamping during orientation adjustment.

[0059] To solve the above problems, the clamping tool provided by the example embodiment of the present application comprises a rack, a tilting structure, at least one limiting structure, and at least one clamping structure arranged on the rack, the intermediate part of the tool is fixed by the clamping structure, and the clamping structure can rotate around its own axis. On the other hand, the limiting structure is arranged on the end of the workpiece. When the workpiece is tilted up or down by the tilting structure, the workpiece remains in place without slipping. Therefore, the workpiece can be kept stable and reliable during rotation and tilting after being placed in the clamping tool.

[0060] It should be noted that the clamping tool provided by the example embodiment of the present application is not only suitable for fixing and clamping large cylindrical workpieces, but also suitable for fixing and clamping large columnar workpieces or other similar circular cross-section workpieces.

[0061] Figure 1 is a structural schematic diagram of the clamping tool according to the embodiment of the present application. As shown in Figure 1 The tool provided by the example embodiment of the present application comprises a rack 10, a tilting structure, at least one limiting structure 30, and at least one clamping structure 20 arranged on the rack 10; the limiting structure 30 is located near the end of the rack 10, and the limiting structure 30 is used to fix the end of the workpiece; each clamping structure 20 comprises a support 22 and a clamping ring 21 rotatably arranged on the support 22, the clamping ring 21 is a fan ring, and the clamping ring 21 is used to fix the intermediate part of the workpiece; the tilting structure comprises a first bracket 41, a second bracket 42, and a first driving mechanism arranged on the second bracket 42, the first bracket 41 is hinged to the rack 10, the first driving mechanism is in transmission connection with the rack 10, and the first driving mechanism is used to drive the rack 10 to rotate around the first bracket 41.

[0062] In actual application, the limiting structure 30 can be one, when the tool is tilted by rotating around the first bracket 41, one limiting structure 30 can be arranged on the end of the workpiece in a lower position to limit the workpiece from tilting and slipping downward. The limiting structure 30 can also be two, that is, the limiting structure 30 is arranged on both ends of the workpiece, no matter which direction the workpiece tilts, the two limiting structures 30 can ensure the stability and reliability of the workpiece.

[0063] Further, the number of clamping structures 20 can be one, when the length span of the workpiece is not large, one clamping structure 20 can be used to clamp the middle region of the workpiece, so as to complete the rotation and tilting of the workpiece and keep the clamping stable. The number of clamping structures 20 can also be multiple, when the length span of the workpiece is large enough, for example, the length-diameter ratio of the workpiece is greater than or equal to 8, multiple clamping structures 20 can be used to clamp the workpiece, so as to complete the rotation and tilting of the workpiece and keep the clamping stable. Figure 1The four clamping structures 20 shown clamp the middle part of the workpiece. The distribution of the plurality of clamping structures 20 should be along the length direction of the rack 10, that is, the first direction, and the specific position of each clamping structure 20 can be selected according to the required support point of the workpiece to prevent additional stress. The arrangement of the plurality of clamping structures 20 is more conducive to the rotation of the workpiece around its own axis.

[0064] In order to adapt to the shape of the large cylindrical workpiece for clamping, the clamping ring 21 of the clamping structure 20 is a fan ring, and the workpiece can be installed in place at the gap of the fan ring. Exemplarily, the central angle of the arc segment of the clamping ring 21 is greater than 180°, which can be suitable for more workpieces of different diameters. The clamping ring 21 is rotatably arranged on the support 22, where the rotatable arrangement means that the clamping ring 21 can rotate around its own central axis.

[0065] Figure 2 is a schematic view of a clamping structure according to an embodiment of the present application; Figure 3 is a schematic view of a clamping ring structure according to an embodiment of the present application; Figure 4 is a schematic view of a support structure according to an embodiment of the present application. As shown, Figure 3 the outer side of each clamping ring 21 has a rack 211, which is located at the middle part of the clamping ring 21; as shown, Figure 4 each support 22 has a gear 222 engaged with the corresponding rack 211.

[0066] In actual application, the arc length of the rack 211 is determined according to the actual angle of rotation of the workpiece around its own axis. The rack 211 is located at the middle part of the clamping ring 21 and its arc matches the arc of the clamping ring 21. The support 22 has a gear 222 engaged with the rack 211 inside, and through the transmission of the power device, the rotation of the gear 222 drives the movement of the rack 211, realizing the rotation of the clamping ring 21.

[0067] As shown, Figures 2-4 when the clamping ring 21 is used in cooperation with the support 22, a plurality of rollers are arranged on the bottom of the support along the circumferential direction of the clamping ring 21, which are used to fit on the outer side of the clamping ring 21, and correspondingly, a plurality of rollers are also arranged on the top of the support to fit on the inner side of the clamping ring 21. The plurality of rollers located on the inner side and the outer side of the clamping ring 21 cooperate, on the one hand, to make the clamping ring 21 rotate smoothly, and on the other hand, to limit the clamping ring 21 in the support 22, so as to form the rotation cooperation relationship between the two.

[0068] When the clamping tool has a plurality of clamping structures 20, considering the synchronism of the rotation of the plurality of clamping structures 20, each of the plurality of supports 22 is fixedly arranged on the rack 10; through the coaxial transmission shaft 221, the gears 222 in each support 22 are drivingly connected.

[0069] like Figure 1 As shown, three snap-fit ​​structures 20 located on the right side of the frame 10 are fixedly mounted on the frame 10 to maintain the stability of the snap-fit ​​structures 20. Meanwhile, the gears 222 in each support 22 of the three snap-fit ​​structures 20 are connected by one or more drive shafts 221. Multiple drive shafts 221 can also be connected by couplings. A single servo motor drives multiple coaxial drive shafts 221, ensuring that the three snap-fit ​​structures 20 remain synchronized when the snap ring 21 rotates, thereby ensuring the stability and force balance of the workpiece and reducing stress concentration.

[0070] like Figure 1 As shown, considering the adaptability of the clamping fixture to various workpiece types and the flexibility of the support points, for example, for workpieces with a long span, some of the multiple supports 22 are slidably mounted on the frame 10 along the first direction, while other supports 22 are fixedly mounted on the frame 10; wherein, the gears 222 fixedly mounted on each support 22 of the frame 10 are connected by a coaxial transmission shaft 221. For example, the snap-fit ​​structure 20 can slide and be positioned along the first direction.

[0071] Figure 10 This is a schematic diagram of the frame structure according to an embodiment of the present invention. Figure 1 and Figure 10 As shown, the support 22 of the leftmost snap-fit ​​structure 20 on the frame 10 is slidably mounted on the second slide rail 12 on the frame 10, while the supports 22 of the three snap-fit ​​structures 20 on the right side of the frame 10 are fixedly mounted on the frame 10. Exemplarily, the snap-fit ​​structures 20 slidably mounted on the frame 10 and the snap-fit ​​structures 20 fixedly mounted on the frame 10 are structurally basically the same. The difference is that the snap-fit ​​structures 20 slidably mounted on the frame 10 not only have a servo motor that individually drives the gear 222 in the support 22, but also have a drive device at a corresponding position on the frame 10 to push the support 22 to slide. Exemplarily, the drive device can be a hydraulic cylinder, electric cylinder, or other linear motion mechanism connected to the support 22, and in some embodiments, no further limitations are made.

[0072] like Figure 1 and Figure 2 As shown, each retaining ring 21 has a clamping part 23 at its end. Along the radial direction of the retaining ring 21, each clamping part 23 located at the end of the retaining ring 21 is slidably disposed on the retaining ring 21.

[0073] The two ends of the clamping ring 21 are provided with clamping portions 23, and the clamping portions 23 can slide and be positioned along the radial direction of the clamping ring 21. Based on this, when the diameter of the tooling is large, the two clamping portions 23 at the ends can also be adjusted, so that the tooling can be installed into the clamping ring 21, and then the sliding distance of the two clamping portions 23 at the ends is adjusted again, so that the two clamping portions 23 are fixed and clamped on both sides of the tooling. As can be seen from the above, the clamping ring 21 of the exemplary embodiment of the present application can adapt to tooling of different diameters, so that the versatility of the tooling is better.

[0074] In order to adjust the radial position of the clamping portions 23 at the two ends of the clamping ring 21, the tooling is also provided with a second driving mechanism 24 at the end of each clamping ring 21, and the second driving mechanism 24 is in driving connection with the corresponding clamping portion 23 at the end of the clamping ring 21. For example, the second driving mechanism 24 can be one of an electric cylinder, a hydraulic cylinder or a cylinder. Taking the cylinder as an example, the end of the clamping ring 21 is provided with a fixed seat, and the clamping portion 23 is slidably arranged on the fixed seat. The side of the fixed seat away from the clamping portion 23 is provided with a cylinder. In order to maintain the smoothness of the movement of the clamping portion 23 and the stability of the clamping, the number of cylinders is two, which are respectively located at the positions close to the two sides of the clamping portion 23. The extension end of the cylinder is connected with the clamping portion 23, so as to drive the clamping portion 23 to approach or move away from the workpiece.

[0075] Considering that the cylindrical workpiece, especially the large thin-walled cylindrical workpiece, is prone to deformation and stress concentration. The end of the clamping portion 23 towards the workpiece to be clamped is provided with an elastic pad 231 for abutting with the surface of the workpiece. Exemplarily, the clamping portion 23 includes a clamping plate connected with the extension end of the cylinder, and the surface of the clamping plate is provided with the elastic pad 231. For example, the pad 231 can be a rubber pad or a film with convex points. By the flexible abutment between the pad 231 and the workpiece, stress concentration on the workpiece caused by clamping is avoided.

[0076] In some embodiments, the clamping part 23 includes a pad 231, a plurality of protrusions 232, and a corresponding fitting part 233 for each protrusion 232. The plurality of protrusions 232 are evenly distributed on the surface of the pad 231, and each fitting part 233 is located at the end of the corresponding protrusion 232 facing away from the pad 231. The plurality of fitting parts 233 are used to match and fit against the surface of the workpiece. The orthographic projection of the protrusions 232 onto the surface of the fitting part 233 facing the pad 231 is located within the surface of the fitting part 233 facing the pad 231. The pad 231, the protrusions 232, and the fitting parts 233 are all components made of elastic material. Exemplarily, the pad 231, the protrusions 232, and the fitting parts 233 are all made of rubber, and the three can be integrally molded. Optionally, the pad 231 and the protrusions 232 can be multi-point membrane structures, and the fitting part 233 is a flexible block with a certain thickness disposed at the end position of the protrusions 232. Compared to existing clamping methods, the exemplary embodiment of the present invention provides a larger contact portion 233 at the end of the protrusion 232. For example, the total area of ​​all contact portions 233 is approximately the same as the surface area of ​​the pad 231. When the clamping portion 23 clamps the workpiece, it ensures complete contact with the curved surface, resulting in uniform force on the workpiece and realizing the conversion of point force to surface force. This allows for flexible adaptive clamping of workpieces of different diameters. It is understood that the surface of the pad 231 can be a plane or a curved surface with a certain curvature. When the surface of the pad 231 is a plane, the height of each protrusion 232 above the surface of the pad 231 is the same.

[0077] In another alternative implementation, such as Figures 2-3 As shown, each retaining ring 21 has at least one clamping part 23 in its middle portion. Exemplarily, two clamping parts 23 are provided near the middle portion of the retaining ring 21, symmetrically arranged on the inner side of the retaining ring 21, for supporting and clamping the bottom of the workpiece. Since these two clamping parts 23 do not require radial adjustment and are fixedly disposed on the inner side of the retaining ring 21, they do not need to be slidably disposed on the retaining ring 21. The specific structure of the two clamping parts 23 located in the middle portion is similar to that of the two clamping parts 23 located at the ends, also consisting of a clamping plate and a pad 231 disposed on the clamping plate.

[0078] For example, the surface of the pad 231 provided on each of the above-mentioned clamping parts 23 that contacts the workpiece is an arc-shaped surface so as to fit with the arc-shaped surface of the workpiece. Optionally, the pad 231 is detachably connected to the clamping plate of the clamping part 23 and can be replaced to adapt to the curvature of the surface of different workpieces.

[0079] Figure 5 This is a schematic diagram of the second support and the first drive mechanism according to an embodiment of the present invention; Figure 6is a first support structure schematic diagram according to an embodiment of the present application. As shown in Figure 5 and Figure 6 The pitch structure of the exemplary embodiment of the present application is formed by the first support 41, the first driving mechanism and the second support 42 to realize the rotating (pitching) action of the frame 10. The first driving mechanism includes a linear driving mechanism, one end of which is hinged to the side of the second support 42 facing the first support 41, and the other end of which is hinged to the frame 10.

[0080] Exemplarily, the linear driving mechanism includes one of an electric cylinder 43, a steam cylinder or a hydraulic cylinder. For the convenience of description, the electric cylinder will be taken as an example for introduction.

[0081] Exemplarily, the number of the electric cylinders 43 is two, and the two electric cylinders 43 are respectively located at the bottom region of the frame 10 close to the sides. The first driving mechanism further includes a motor 44, which is located at the middle part between the two electric cylinders 43 and is in driving connection with the two electric cylinders 43 respectively. As shown in Figure 5 the fixed end of each electric cylinder 43 is hinged to the side of the second support 42 facing the first support 41, and the telescopic end of each electric cylinder 43 is hinged to the bottom of the frame 10. The two electric cylinders 43 are respectively located at the positions close to the two sides in the width direction of the frame 10, thereby providing uniform and stable power for the rotating of the frame 10 along the first support 41.

[0082] Exemplarily, the above-mentioned motor 44 is arranged at the middle part between the two electric cylinders 43 and is in driving connection with each electric cylinder 43 through corresponding shafts. Since the two shafts are located at the same axial position and have the same length, the two electric cylinders 43 located at the two sides of the motor 44 have good synchronization and the driving forces received are also more balanced, so that the frame 10 can be stably rotated in the process of pitching.

[0083] As shown in Figure 6 the hinge between the first support 41 and the frame 10 is also hinged by two pin shafts located close to the two sides in the width direction of the frame 10. Since the two hinge positions are also located at the same axial position, the rotating of the frame 10 is also relatively stable in the process of rotating around the first support 41.

[0084] Figure 7 is a limiting structure schematic diagram according to an embodiment of the present application; Figure 8 is a limiting structure schematic diagram according to another embodiment of the present application; Figure 9 is another view of the limiting structure schematic diagram according to another embodiment of the present application. As shown in Figures 7-8 the limiting structure 30 has various forms, and two different limiting structures will be taken as examples for description.

[0085] In an optional embodiment, as shown in Figure 7 , the limiting structure 30 is a fixed height limiting structure for limiting the end of the workpiece. The limiting structure 30 comprises a clamping plate 31 and a clamping device 32 slidingly arranged on the rack 10, the clamping plate 31 being slidingly arranged on the side of the clamping device 32 facing the workpiece; the sliding direction of the clamping device 32 on the rack 10 and the sliding direction of the clamping plate 31 on the clamping device 32 are both the first direction; the clamping plate 31 is used to fit on one end of the workpiece.

[0086] Exemplarily, as shown in Figure 10 , the clamping device 32 is slidingly arranged on the first slide rail 11 on the rack 10, specifically, the clamping device 32 is connected to the extension end of the linear motion mechanism, such as a cylinder, a hydraulic cylinder or an electric cylinder. Through the control of the linear motion mechanism, the position of the clamping device 32 on the first slide rail 11 can be adjusted, and then the clamping plate 31 on the clamping device 32 is fitted or away from the end of the workpiece to form a limit. Exemplarily, in order to further improve the accuracy of the position adjustment between the clamping plate 31 and the workpiece, in addition to the clamping device 32 slidingly arranged on the first slide rail 11, the clamping plate 31 is also slidingly arranged on the clamping device 32. It can be understood that the sliding direction of the above-mentioned clamping plate 31 is also the first direction, that is, the length direction of the rack 10, to approach or away from the end of the workpiece. Exemplarily, the sliding control mechanism of the clamping plate 31 is driven by a mechanism with precise adjustment function, such as a cylinder, which is not limited in some embodiments.

[0087] The above-mentioned limiting structure 30 as shown in Figure 10 is suitable for the end of the workpiece being a plane, such as the bottom end of a rocket. When the end of the workpiece is conical, such as the head of a rocket, the fixed height clamping plate 31 may not be suitable for limiting it. Based on this, the exemplary embodiments of the present application provide a limiting structure 30 in which the height of the clamping plate 31 can be adjusted to adapt to different workpiece clamping parts. Thus, the versatility of the clamping tool is improved.

[0088] As shown in Figures 8-9 , in the clamping tool of the exemplary embodiments of the present application, the clamping device 32 of the limiting structure 30 comprises a sliding plate 322 and a lifting mechanism arranged on the sliding plate 322, the sliding plate 322 being slidingly arranged on the rack 10; the lifting mechanism comprises a base 321 and a lead screw 324 connected to the bottom of the base 321, the lead screw 324 being movably arranged on the sliding plate 322, the clamping plate 31 being slidingly arranged on the side of the base 321 facing the workpiece; the lifting mechanism further comprises a third driving mechanism 323, the third driving mechanism 323 being in transmission connection with the lead screw 324.

[0089] As shown in Figure 8 and Figure 10The bottom of the sliding plate 322 is provided with a sliding groove, which is arranged on the third sliding rail 13 of the rack 10. It should be noted that the driving mechanism of the sliding plate 322 can be a cylinder or a hydraulic cylinder, and the sliding plate 322 can be driven to slide along the third sliding rail 13 and positioned by controlling the driving mechanism. It can be understood that the second sliding rail 12 and the third sliding rail 13 can be adjacent sliding rails at the ends, which can be determined according to actual conditions. Since the clamping plate 31 is slidably arranged on the side of the base 321 facing the workpiece, the height of the clamping plate 31, that is, the distance between the rack 10 and the clamping plate 31, can be adjusted by lifting the base 321 to adapt to the limiting of different workpiece ends. In this embodiment, the base 321 is movably connected to the sliding plate 322 by a lead screw 324. Specifically, one end of the lead screw 324 is fixedly connected to the bottom of the base 321, and the other end of the lead screw 324 penetrates the sliding plate 322. In order to keep the base 321 stable during lifting, two light shafts are arranged on both sides of the bottom of the base 321, and two holes are arranged on the sliding plate 322 for the light shafts to penetrate. The two light shafts can slide in the holes, thereby limiting the freedom of the base 321.

[0090] As shown in Figure 9 In order to control the lifting of the base 321, the lifting mechanism further comprises a third driving mechanism 323. The third driving mechanism 323 is a hand wheel, which can control the lifting of the lead screw 324 through the cooperation of the lead screw nut, thereby controlling the height of the base 321 and adjusting the height of the clamping plate 31. The manual control by the hand wheel can avoid complicating the lifting system, for example, compared with complex circuit control and accurate measurement, manual control is simpler and can fully meet the height requirements of the clamping plate 31.

[0091] It should be noted that the two limiting structures 30 can be arranged at both ends of the rack 10. Alternatively, the same limiting structure 30 can be arranged at both ends of the rack 10, which can be determined according to the end of the workpiece to be limited.

[0092] In some embodiments, in order to meet the requirement of precise pose adjustment of the workpiece, the clamping tool of the exemplary embodiment of the application further comprises two laser scanners, one of which is located on the ground and the other is located on the rack 10; when the rack 10 is in a horizontal state, the two laser scanners are located on the same horizontal plane.

[0093] In actual application, the two installed laser scanners read the position information of the workpiece and feed back to the console, and the clamping tool can be controlled to accurately position the workpiece according to the position information of the workpiece, so as to ensure the positioning accuracy. The console is in communication connection with each driving device, so as to control the relative movement of each moving part, such as the adjustment of the pitch angle, the sliding adjustment of each clamping part and the limiting structure, and the clamping structure slidingly arranged on the rack. For example, one of the two laser scanners is installed on the ground on one side of the console, and the other is installed on the rack, such as being arranged at a position between the two clamping structures 20 fixedly arranged on the rack 10, and the heights of the two laser scanners are consistent, so that the horizontal and angular detection and feedback of the workpiece during the positioning process are realized.

[0094] The exemplary embodiments of the present application also provide a clamping assembly, which comprises the clamping tool and the air bag described above, and the air bag is used to fill the cavity of the workpiece to support the inner wall of the workpiece.

[0095] When the workpiece is a thin-walled cylindrical workpiece, in order to realize the adaptive flexible clamping of the workpiece and prevent the workpiece from deforming and causing stress concentration during the clamping process, an air bag can be placed in the cavity of the workpiece to realize the support of the entire inner part of the workpiece, and the air bag cooperates with the clamping part to realize the fixed clamping of the workpiece.

[0096] In another optional embodiment, high-pressure gas is filled in the cavity of the workpiece, so that the workpiece has sufficient rigidity and does not deform during subsequent milling and other machining operations. For example, a sealing plate is made and installed at both ends of the workpiece, so as to form a sealed space in the area to be clamped of the workpiece, and high-pressure gas is filled in the corresponding space, so that the inside of the clamped part of the workpiece has a certain support, and cooperates with the clamping part to realize the adaptive flexible clamping of the workpiece.

[0097] The exemplary embodiments of the present application also provide a workpiece positioning method, and the workpiece is a large cylindrical workpiece, and the above-mentioned tool is used for positioning, and the method comprises the following steps:

[0098] Step 1101: hoist the workpiece to the installation position, and the clamping structure 20 fixedly arranged on the rack 10 clamps the workpiece.

[0099] High-pressure gas is filled in the cavity of the workpiece, or an air bag is placed in the cavity of the workpiece to support the workpiece inside;

[0100] The workpiece is hoisted to the installation position by a special lifting tool, for example, the workpiece is hoisted into the clamping part 23 fixedly arranged on the inner side of the clamping ring 21 from the opening position of the clamping ring 21;

[0101] The clamping part 23 located at the end position of the clasp ring 21 is controlled to slide and adhere the pad 231 to the surface of the workpiece, thereby preliminarily fixing the workpiece, and the lifting device is removed.

[0102] Step 1102: Position and clamp the workpiece by each sliding clamping structure 20 arranged on the rack 10.

[0103] According to the set program, for example, according to the length of the workpiece and the setting of the appropriate support point, the clamping structure 20 arranged on the rack 10 is driven by the driving mechanism to slide to the preset position and be fixed, and then the clamping part 23 located at the end position of the clasp ring 21 is controlled to slide and adhere the pad 231 to the surface of the workpiece.

[0104] Step 1103: Position and fix the limiting structure at both ends of the workpiece respectively.

[0105] The driving mechanism of each limiting structure is controlled by the console to slide the limiting structure 30 to the preset position and be fixed, and then the position of the clamping plate 31 in the first direction is adjusted, so that the clamping plate 31 is adhered to the corresponding end of the workpiece. When the height of the part to be limited at the end of the workpiece is inconsistent with the height of the clamping plate 31, the height of the base 321 on which the clamping plate 31 is located is controlled by the console to control the lifting mechanism, so that the clamping plate 31 reaches the position corresponding to the end of the workpiece. Thus, the positioning and clamping are performed on the two end surfaces of the workpiece.

[0106] Step 1104: Obtain the position information of the workpiece, and adjust the pitch angle and the rotation angle around the axis of the workpiece.

[0107] The position information of the workpiece is read by two laser scanners (not shown in the figure) and fed back to the console, and the console adjusts the pitch angle and the state of two degrees of freedom around the axis direction of the workpiece by controlling the motion mechanism.

[0108] As can be seen from the above, the clamping tool of the present application realizes the two-degree-of-freedom posture adjustment of the large thin-walled cylindrical workpiece around the axis and the pitch, the rotation synchronization between the clasp rings is realized by the shaft coupling for the posture adjustment around the axis direction, the posture adjustment difficulty is simplified, the lifting and lowering of the entire posture adjustment tool is realized by the cylinder below the rack for the pitch angle adjustment. The posture adjustment in the remaining directions is ensured by the structure of the tool itself, which can reduce the complexity of the tool and improve the efficiency and accuracy of the posture adjustment.

[0109] Further, the clamping and posture adjustment of the thin-walled cylindrical workpiece with different diameters and lengths can be realized by the cooperation of the plurality of fixed clamping structures and one clamping structure, the flexible clamping of the product is realized, and strong clamping rigidity and stability can be provided for the workpiece machining.

[0110] Those skilled in the art should understand that the above-mentioned embodiments are only intended to clearly illustrate the present application, and are not intended to limit the scope of the present application. Other changes or modifications can be made on the basis of the above disclosure, and these changes or modifications are still within the scope of the present application.

Claims

1. A clamping fixture, characterized in that, For clamping large cylindrical workpieces, the tooling includes a frame, a pitching structure, at least one limiting structure, and at least one snap-fit ​​structure provided on the frame. The limiting structure is located near the end of the frame and is used to fix the end of the workpiece. Each of the snap-fit ​​structures includes a support and a snap ring rotatably disposed on the support. The snap ring is a fan ring and is used to fix the middle part of the workpiece. Each snap ring has a clamping part at its end. Along the radial direction of the snap ring, each clamping part located at the end of the snap ring is slidably disposed on the snap ring. The clamping part includes a pad, a plurality of protrusions, and a corresponding fitting part for each of the protrusions. The plurality of protrusions are evenly distributed on the surface of the pad, and each of the fitting parts is located at the end of the corresponding protrusion away from the pad. Multiple of the aforementioned fitting portions are used to match and adhere to the surface of the workpiece; the orthographic projection of the protrusion on the surface of the fitting portion facing the pad is located within the surface of the fitting portion facing the pad; the total area of ​​each fitting portion is the same as the surface area of ​​the pad; the pad, the protrusion, and the fitting portions are all components made of elastic material; A portion of the plurality of supports is slidably disposed on the frame along a first direction, while another portion of the supports is fixedly disposed on the frame. The transmission is achieved by a gear drive connection fixed in each of the supports of the frame via a coaxial drive shaft. The pitch structure includes a first support, a second support, and a first drive mechanism located on the second support. The first support is hinged to the frame, the first drive mechanism is driven to the frame, and the first drive mechanism is used to drive the frame to rotate around the first support.

2. The tooling according to claim 1, characterized in that, The tooling includes multiple snap-fit ​​structures, each of which is distributed along a first direction, which is the length direction of the frame.

3. The tooling according to claim 2, characterized in that, Each of the retaining rings has a rack on its outer side, the rack being located in the middle of the retaining ring, and each of the supports has a gear that meshes with the corresponding rack.

4. The tooling according to claim 3, characterized in that, Each of the plurality of supports is fixedly mounted on the frame; The gears in each of the supports are connected by a coaxial drive shaft.

5. The tooling according to claim 3, characterized in that, Each of the retaining rings has at least one clamping part in the middle, and each clamping part located in the middle of the retaining ring is fixedly disposed on the inner side of the retaining ring.

6. The tooling according to claim 4, characterized in that, Each of the retaining rings is further provided with a second driving mechanism at its end, the second driving mechanism being kinetically connected to the clamping part located at the corresponding end of the retaining ring.

7. The tooling according to any one of claims 1-6, characterized in that, The first drive mechanism includes a linear drive mechanism, one end of which is hinged to the side of the second bracket facing the first bracket, and the other end of which is hinged to the frame.

8. The tooling according to any one of claims 1-6, characterized in that, The fixture also includes two laser scanners, one of which is located on the ground and the other is located on the frame; When the rack is horizontal, the two laser scanners are located on the same horizontal plane.

9. A method for adjusting the posture of a workpiece, characterized in that, The workpiece is a large cylindrical workpiece, and its orientation is adjusted using the tooling described in any one of claims 1-8.

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