Self-piercing riveting device and method of use

Abstract

This invention discloses a self-piercing riveting device and its usage method, relating to the field of material joining and riveting equipment technology. It includes a worktable, a planar position adjustment mechanism, a clamping mechanism, a bottom die mechanism, and a riveting mechanism. The planar position adjustment mechanism allows the output end of the attitude adjustment mechanism to move and adjust in the X and Y axes. The bottom die mechanism includes a mounting base and multiple sets of bottom die assemblies arranged along the Y axis. Each bottom die assembly includes a first attitude adjustment mechanism and multiple lifting riveting bottom dies. The first attitude adjustment mechanism can drive it to rotate around the X axis and lift / lower around the Z axis. The riveting mechanism includes a second attitude adjustment mechanism and a riveting head. The riveting head is mounted on the output end of the second attitude adjustment mechanism, and the fixed end of the second attitude adjustment mechanism is mounted on the worktable, positioning the riveting head above the bottom die mechanism. This device can expand the application range of complex spatial attitude areas, meet diverse production needs, reduce cracking risks, and improve the consistency of riveting quality and product reliability.

Description

Technical Field

[0001] This invention relates to the field of material joining and riveting equipment technology, and in particular to a self-piercing riveting device and its usage method. Background Technology

[0002] Self-piercing riveting, as a commonly used mechanical joining process, is widely used in the automotive, rail transportation, and equipment manufacturing industries due to its advantages such as eliminating the need for pre-drilled holes, high connection efficiency, and applicability to connecting multi-material plates. However, with the increasing adoption of lightweight and complex structural components, the parts to be joined exhibit diverse characteristics in terms of size range, riveting point distribution, and spatial orientation of the riveting area.

[0003] Existing self-piercing riveting equipment has many limitations. On the one hand, its bottom die arrangement is usually fixed or in the form of a bottom die array, and the adjustable range of the number and position of the bottom dies is limited. When dealing with workpieces of different sizes, varying numbers of riveting points, or irregularly shaped parts, it is often necessary to replace special tooling or rearrange the bottom dies. This not only leads to insufficient equipment adaptability but also results in high changeover costs, making it difficult to meet the flexible production needs of multi-point rapid riveting.

[0004] On the other hand, in actual assembly, the riveting surfaces of the workpieces may be tilted, stepped, or have local height differences, resulting in inconsistencies in the spatial orientation and height of the riveting area. If the orientation and height of the riveting head and the bottom mold cannot be quickly matched, it can easily lead to reduced alignment efficiency or fluctuations in forming stability, thereby affecting the consistency of the riveting.

[0005] Furthermore, for brittle or low-ductility materials such as die-cast magnesium, as well as multi-material laminated structures, defects such as cracks or brittle fractures are more likely to occur in the riveting area when the plasticity is insufficient at room temperature. Although local heating of the riveting area can improve the plasticity and ductility of the material, reduce deformation resistance, and help suppress cracks and improve forming stability, there is currently a lack of effective monitoring and judgment of process signals such as riveting pressure, which is not conducive to timely identification of abnormal riveting points and ensuring batch quality consistency.

[0006] Therefore, there is an urgent need for a self-piercing riveting device and its riveting method that can reconfigure the bottom mold as needed, adjust the riveting joint and the posture and height of the bottom mold, and have thermal assistance and pressure monitoring capabilities, so as to meet the flexible and high-quality riveting requirements in complex structural components, multi-point and multi-material connection scenarios. Summary of the Invention

[0007] The purpose of this invention is to provide a self-piercing riveting device and its usage method to solve the problems existing in the prior art. It can adapt to workpieces of different sizes and with different riveting point distributions, realize rapid changeover and multi-point riveting adaptation, improve the versatility of the equipment and production efficiency; effectively improve the support and fit and reaction force consistency of complex areas such as curved surfaces and stepped surfaces, effectively improve riveting stability, and ensure riveting quality; expand the application range of complex spatial posture areas, meet diverse production needs, reduce cracking risk, significantly improve the consistency of riveting quality, and enhance product reliability.

[0008] To achieve the above objectives, the present invention provides the following solution: This invention provides a self-piercing riveting device, comprising: a worktable, a planar position adjustment mechanism, a clamping mechanism, a bottom die mechanism, and a riveting mechanism. The planar position adjustment mechanism is mounted on the worktable and enables the output end of the attitude adjustment mechanism to achieve positional adjustment in the X-axis and Y-axis directions. The clamping mechanism is mounted on the output end of the planar position adjustment mechanism. The bottom die mechanism includes a mounting base and multiple sets of bottom die assemblies arranged along the Y-axis direction. The mounting base is detachably clamped and fixed to the output end of the planar position adjustment mechanism by the clamping mechanism. The bottom die assembly includes a first attitude adjustment mechanism and multiple lifting riveting bottom dies, which are arranged and mounted on the first attitude adjustment mechanism along the X-axis direction. At the output end of the structure, the first posture adjustment mechanism can drive the multiple lifting riveting bottom dies to rotate around the X-axis and rise and fall in the Z-axis direction. The lifting riveting bottom dies can be independently adjusted in the Z-axis direction to adapt to the workpieces to be riveted with different contour surfaces. The riveting mechanism includes a second posture adjustment mechanism and a riveting head. The riveting head is installed at the output end of the second posture adjustment mechanism, and the fixed end of the second posture adjustment mechanism is installed on the worktable, so that the riveting head is located above the bottom die mechanism to adjust the posture and position of the riveting head so that the riveting head can be aligned with the riveting points corresponding to the different contour surfaces, and complete the riveting operation in conjunction with the lifting riveting bottom dies below that have been adjusted to the corresponding height.

[0009] Preferably, the planar position adjustment mechanism includes a Y-axis drive unit, a Y-axis moving support platform, an X-axis drive unit, and an X-axis moving support platform. The Y-axis drive unit is mounted on the worktable, the Y-axis moving support platform is mounted on the output end of the Y-axis drive unit to move along the Y-axis, the X-axis drive unit is mounted on the Y-axis moving support platform, the X-axis moving support platform is mounted on the output end of the X-axis drive unit to move along the X-axis, and the clamping mechanism is fixedly mounted on the X-axis moving support platform.

[0010] Preferably, the Y-axis drive unit includes a first drive motor, a first drive gear, a first toothed plate, and multiple Y-axis guide rails. The multiple Y-axis guide rails are fixed parallel to each other on the worktable. A first slider is correspondingly provided at the bottom of the Y-axis movable support platform, slidingly engaging with the Y-axis guide rails. The first toothed plate is fixed parallel to the Y-axis guide rails at the bottom of the Y-axis movable support platform. The first drive motor is fixedly mounted on the worktable. The first drive gear is fixedly connected to the output shaft of the first drive motor, and the first drive gear meshes with the first toothed plate to drive the Y-axis movable support platform to reciprocate along the Y-axis direction. The X-axis drive unit includes a second drive motor, a second drive gear, a second toothed plate, and multiple X-axis guide rails. The multiple X-axis guide rails are fixed parallel to each other on the Y-axis movable support platform. The bottom of the X-axis movable support platform is provided with a second slider that slides in cooperation with the X-axis guide rail. The second toothed plate is fixed to the bottom of the X-axis movable support platform parallel to the X-axis guide rail. The second drive motor is fixedly installed on the Y-axis movable support platform. The second drive gear is fixedly connected to the output shaft of the second drive motor, and the second drive gear meshes with the second toothed plate to drive the X-axis movable support platform to reciprocate along the X-axis direction. The clamping mechanism includes a receiving groove opened on the upper surface of the X-axis movable support platform and a clamping drive cylinder installed on the side of the X-axis movable support platform. The output end of the clamping drive cylinder is connected to a detachable clamping block through a swing arm type clamping transmission mechanism. The detachable clamping block is used to clamp and lock the mounting base in the receiving groove.

[0011] Preferably, the first posture adjustment mechanism includes a first lifting drive unit, a first rotary drive unit, and a bearing groove. The fixed end of the first lifting drive unit is mounted on the mounting base, and the output end of the first lifting drive unit is connected to the first rotary drive unit to drive the first rotary drive unit to lift along the Z-axis. The output end of the first rotary drive unit is connected to the bearing groove to drive the bearing groove to rotate around a pivot parallel to the X-axis. Multiple lifting riveting bottom molds are arranged and mounted on the bearing groove along the X-axis.

[0012] Preferably, the first lifting drive unit includes a lifting hydraulic cylinder, a vertical guide plate, and a lifting plate. The cylinder body of the lifting hydraulic cylinder is fixedly installed on the mounting base. The vertical guide plate is fixedly installed on the mounting base along the Z-axis direction. A guide sleeve that slides with the vertical guide plate is fixedly provided at the end of the lifting plate. The top end of the piston rod of the lifting hydraulic cylinder is fixedly connected to the lifting plate. The first rotary drive unit is installed on the lifting plate. The first rotary drive unit includes a support column, a mounting side plate, a first rotary drive motor, a support shaft, a first driving wheel, a first driven wheel, brake friction pads, and a brake disc. The support column is vertically fixedly connected to the lifting plate. One end of the support shaft is fixedly connected to the top of the support column, and the other end is rotatably connected to the bearing groove. The mounting side plate is fixedly connected to one end of the bearing groove. The first rotary drive motor is mounted on the mounting side plate. The first driving wheel is fixedly connected to the output shaft of the first rotary drive motor. The first driven wheel is fixedly sleeved on the outer circumference of the support shaft. The first driving wheel and the first driven wheel mesh and drive each other. The brake disc is sleeved and fixedly mounted on the support shaft. The brake friction pads are correspondingly mounted on the mounting side plate.

[0013] Preferably, the lifting riveting bottom mold includes: a mounting base, a first lifting drive motor, a first ball screw pair, a lifting output plate, a bottom mold body, a heating element, and a temperature measuring element. The mounting base is detachably fixed to the bearing groove. The first lifting drive motor is installed in the mounting base. The first ball screw pair is connected to the output end of the first lifting drive motor along the Z-axis direction. The lifting output plate is fixedly connected to the screw nut of the first ball screw pair. The mounting base is provided with a guide key extending along the Z-axis direction. The lifting output plate is slidably engaged with the guide key. The bottom mold body is fixedly installed on the top of the lifting output plate. The top of the bottom mold body is provided with a forming cavity that matches the riveting head. The heating element and the temperature measuring element are both disposed in the bottom mold body or adjacent to the forming cavity.

[0014] Preferably, the lifting riveting bottom mold further includes a pressure sensor, which is disposed on the force transmission path between the lifting output plate and the bottom mold body, and is used to collect pressure signals in real time during the riveting process.

[0015] Preferably, the second posture adjustment mechanism includes a second lifting drive unit and a second rotary drive unit. The fixed end of the second lifting drive unit is mounted on the worktable, and the output end is connected to the second rotary drive unit for transmission, driving the second rotary drive unit to move up and down along the Z-axis. The output end of the second rotary drive unit is connected to the rivet joint for transmission, enabling the rivet joint to rotate around a rotating shaft parallel to the X-axis, thereby adjusting the riveting angle of the rivet joint.

[0016] Preferably, the second lifting drive unit includes a lifting guide column, a second lifting drive motor, a second ball screw pair, and a lifting slide. The lifting slide is slidably engaged with the lifting guide column in the Z-axis direction. The second lifting drive motor is mounted on the bottom of the lifting guide column. The second ball screw pair is connected to the output end of the second lifting drive motor along the Z-axis direction. The lifting slide is fixedly connected to the screw nut of the second ball screw pair. The second rotary drive unit includes a support plate, a second rotary drive motor, a rotary transmission shaft, a second driving wheel, a second driven wheel, and a mounting base. The support plate is mounted on the lifting slide. The rotary drive shaft is connected to the support plate. The second rotary drive motor is mounted on the support plate. The second driving wheel is fixedly connected to the output shaft of the second rotary drive motor. The second driven wheel is fixedly sleeved on the outer circumference of the rotary drive shaft. The second driving wheel and the second driven wheel mesh and drive each other. The mounting base is fixedly connected to the middle of the rotary drive shaft. The rivet head is fixedly mounted on the mounting base and can rotate synchronously with the rotary drive shaft to adjust the riveting angle. The lifting slide and the mounting base are provided with through slots at corresponding positions. The through slots are used to allow the rivet head to pass through and avoid the rotation stroke of the rivet head.

[0017] The present invention also provides a method of using the self-piercing riveting device as described in any of the preceding claims, comprising the following steps: S1: Based on the size of the workpiece to be riveted and the distribution of the rivet points, select the corresponding number of lifting riveting bottom dies and arrange them along the X-axis direction on the mounting base to form a reconfigurable bottom die array. S2: The mounting base is detachably clamped and fixed to the output end of the planar position adjustment mechanism by means of a clamping mechanism; S3: Place the workpiece to be riveted on the bottom mold mechanism and make the riveting area initially aligned with the forming cavity of the corresponding lifting riveting bottom mold; S4: Activate the planar position adjustment mechanism to move the bottom mold mechanism in the X-axis and Y-axis directions, and accurately align the target riveting point directly below the riveting head; S5: Based on the curved contour of the surface of the workpiece to be riveted, drive the first posture adjustment mechanism to drive multiple lifting riveting bottom dies to rotate around the rotating shaft in the X-axis direction and to lift and lower as a whole in the Z-axis direction, and drive each lifting riveting bottom die to lift and lower independently in its own Z-axis direction, so that the forming cavity of each lifting riveting bottom die is stably attached to the corresponding area of ​​the surface of the workpiece to be riveted. S6: Activate the second attitude adjustment mechanism to adjust the attitude and position of the rivet joint so that the downward pressing direction of the rivet joint is consistent with the normal of the point to be riveted. S7: Drive the rivet head to press down, and cooperate with the lifting rivet bottom mold below which has been adjusted in height to complete the pressing in of the rivet and the forming of the flared foot.

[0018] The present invention achieves the following technical effects compared to the prior art: This invention provides a self-piercing riveting device and its usage method. Through a planar position adjustment mechanism and a reconfigurable bottom die mechanism, the number and position of the bottom dies can be flexibly adjusted according to the size and riveting point distribution of different workpieces. Quick changeovers can be completed without changing special tooling, adapting to multi-point riveting needs, effectively improving the equipment's versatility, reducing changeover costs, and increasing production efficiency. A first attitude adjustment mechanism drives the overall pitch, rotation, and lifting of multiple sets of lifting riveting bottom dies. Combined with the independent lifting adjustment of each lifting riveting bottom die, and the second attitude adjustment mechanism's adjustment of the rivet joint's attitude, the bottom die and rivet joint can simultaneously match the spatial attitude and height of complex riveting areas such as curved surfaces and stepped surfaces. This ensures fitting stability and reaction force consistency, effectively improving riveting stability, guaranteeing riveting quality, expanding the application range of complex spatial attitude areas, and meeting diverse production needs. Furthermore, by integrating heating and temperature measuring elements into the lifting riveting bottom mold, the riveting area can be preheated, which can improve the plasticity of brittle or low-ductility materials, reduce deformation resistance, effectively suppress crack generation, and reduce the risk of cracking. Furthermore, the pressure sensor integrated in the bottom mold can collect pressure signals during the riveting process in real time, which facilitates timely identification of abnormal riveting points, effectively ensuring the consistency of riveting quality in mass production and improving the reliability of the final product. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the overall structure of the self-piercing riveting device provided by the present invention. Figure 2 A schematic diagram of the bottom mold removal mechanism of the self-piercing riveting device provided by the present invention; Figure 3 This is a schematic diagram of the Y-axis drive unit in the self-piercing riveting device provided by the present invention. Figure 4 This is a schematic diagram of the X-axis driving unit in the self-piercing riveting device provided by the present invention. Figure 5This is a schematic diagram of the bottom mold mechanism in the self-piercing riveting device provided by the present invention; Figure 6 This is a schematic diagram of the structure of the first rotary drive unit and the bearing groove in the self-piercing riveting device provided by the present invention. Figure 7 A schematic diagram of the lifting riveting bottom mold in the self-piercing riveting device provided by the present invention; Figure 8 This is a schematic diagram of the punching and riveting mechanism in the self-punching riveting device provided by the present invention. Figure 9 A schematic diagram of the self-piercing riveting device provided by the present invention corresponding to conventional planar riveting operation. Figure 10 A schematic diagram of the self-piercing riveting device provided by the present invention corresponding to a high-level riveting operation state; Figure 11 This is a schematic diagram of the self-piercing riveting device provided by the present invention, corresponding to the riveting operation of the inclined riveting surface.

[0021] Figure 12 A schematic diagram of the riveting joint in the self-piercing riveting device provided by the present invention; In the diagram: 1. Workbench; 2. Planar position adjustment mechanism; 21. First drive motor; 22. First drive gear; 23. First gear plate; 24. Y-axis guide rail; 25. Y-axis moving support platform; 26. Second drive motor; 27. Second drive gear; 28. Second gear plate; 29. ​​X-axis guide rail; 210. X-axis moving support platform; 3. Clamping mechanism; 4. Bottom mold mechanism; 41. Mounting base; 42. First posture adjustment mechanism; 421. Lifting hydraulic cylinder; 422. Vertical guide plate; 423. Lifting plate; 424. Support column; 425. Mounting side plate; 426. First rotary drive motor; 427. Support shaft; 428. First driving wheel; 429. First driven wheel; 4210. 4211. Moving friction plate; 4212. Brake disc; 4213. Bearing groove; 43. Lifting riveting bottom mold; 431. Mounting base; 432. First lifting drive motor; 433. First ball screw pair; 434. Lifting output plate; 435. Bottom mold body; 4351. Forming cavity; 436. Heating element; 437. Temperature measuring element; 438. Pressure sensor; 5. Riveting mechanism; 51. Lifting guide column; 52. Second lifting drive motor; 53. Second ball screw pair; 54. Lifting slide; 55. Support plate; 56. Second rotary drive motor; 57. Rotary transmission shaft; 58. Second driving wheel; 59. Second driven wheel; 510. Mounting seat; 511. Riveting joint; 6. Workpiece to be riveted. Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] The purpose of this invention is to provide a self-piercing riveting device and its usage method to solve the problems existing in the prior art. It can adapt to workpieces of different sizes and with different riveting point distributions, realize rapid changeover and multi-point riveting adaptation, improve the versatility of the equipment and production efficiency; effectively improve the support and fit and reaction force consistency of complex areas such as curved surfaces and stepped surfaces, effectively improve riveting stability, and ensure riveting quality; expand the application range of complex spatial posture areas, meet diverse production needs, reduce cracking risk, significantly improve the consistency of riveting quality, and enhance product reliability.

[0024] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0025] Example 1 This embodiment provides a self-piercing riveting device, such as Figures 1-12As shown, the device includes: a worktable 1, a planar position adjustment mechanism 2, a clamping mechanism 3, a bottom mold mechanism 4, and a punching and riveting mechanism 5. The planar position adjustment mechanism 2 is mounted on the worktable 1 and enables the output end of the attitude adjustment mechanism to achieve positional adjustment in the X-axis and Y-axis directions. The clamping mechanism 3 is mounted on the output end of the planar position adjustment mechanism 2. The bottom mold mechanism 4 includes a mounting base 41 and multiple sets of bottom mold assemblies arranged along the Y-axis direction. The mounting base 41 is detachably clamped and fixed to the output end of the planar position adjustment mechanism 2 by the clamping mechanism 3. The bottom mold assembly includes a first attitude adjustment mechanism 42 and multiple lifting riveting bottom molds 43. The multiple lifting riveting bottom molds 43 are arranged along the X-axis direction and mounted on the output end of the first attitude adjustment mechanism 42. The first attitude adjustment mechanism 42 can drive multiple... The lifting riveting base die 43 rotates around the X-axis and rises and falls along the Z-axis. The lifting riveting base die 43 can be independently adjusted in its Z-axis direction to adapt to workpieces 6 with different contours. The riveting mechanism 5 includes a second posture adjustment mechanism and a riveting head 511. The riveting head 511 is installed at the output end of the second posture adjustment mechanism, and the fixed end of the second posture adjustment mechanism is installed on the worktable 1, positioning the riveting head 511 above the base die mechanism 4. This adjusts the posture and position of the riveting head 511, allowing it to align with the riveting points on different contours. Combined with the lifting riveting base die 43 adjusted to the corresponding height, the riveting operation is completed. This overall structural design gives the self-piercing riveting device high flexibility and adaptability. The planar position adjustment mechanism 2 enables precise position adjustment of the base die mechanism 4 in the plane, meeting the needs of workpieces 6 with different sizes and riveting point distributions, thus improving the equipment's versatility. The design of the bottom mold mechanism 4, especially the first posture adjustment mechanism 42 and the independently liftable riveting bottom mold, can effectively adapt to workpieces with different contour surfaces, improve the support and fit of complex-shaped workpieces, and ensure riveting stability. The punching and riveting mechanism 5 adjusts the posture and position of the rivet head 511 through the second posture adjustment mechanism to ensure that the rivet head 511 is precisely aligned with the riveting point, thereby improving the riveting quality.

[0026] In a preferred embodiment, the planar position adjustment mechanism 2 includes a Y-axis drive unit, a Y-axis moving support platform 25, an X-axis drive unit, and an X-axis moving support platform 210. The Y-axis drive unit is mounted on the worktable 1, the Y-axis moving support platform 25 is mounted on the output end of the Y-axis drive unit for movement along the Y-axis, the X-axis drive unit is mounted on the Y-axis moving support platform 25, and the X-axis moving support platform 210 is mounted on the output end of the X-axis drive unit for movement along the X-axis. The clamping mechanism 3 is fixedly mounted on the X-axis moving support platform 210. This dual-drive unit and moving support platform structure design enables independent and precise position adjustment of the bottom mold mechanism 4 in both the X and Y directions. By controlling the movement in the Y and X directions respectively, the bottom mold mechanism 4 can be quickly and accurately positioned to the required position, greatly improving the equipment's adaptability to different riveting point positions, meeting diverse riveting task requirements, and enhancing the equipment's versatility and production efficiency.

[0027] In a preferred embodiment, the Y-axis drive unit includes a first drive motor 21, a first drive gear 22, a first toothed plate 23, and multiple Y-axis guide rails 24. The multiple Y-axis guide rails 24 are fixed parallel to each other on the worktable 1. A first slider corresponding to the bottom of the Y-axis movable support platform 25 is provided, slidingly engaging with the Y-axis guide rails 24. The first toothed plate 23 is fixed parallel to the Y-axis guide rails 24 and fixed to the bottom of the Y-axis movable support platform 25. The first drive motor 21 is fixedly mounted on the worktable 1. The first drive gear 22 is fixedly connected to the output shaft of the first drive motor 21, and the first drive gear 22 meshes with the first toothed plate 23 to drive the Y-axis movable support platform 25 to reciprocate along the Y-axis direction. The X-axis drive unit includes a second drive motor 26, a second drive gear 27, a second toothed plate 28, and multiple X-axis guide rails 29. The multiple X-axis guide rails 29 are fixed parallel to each other on the Y-axis movable support platform 25. A first slider corresponding to the bottom of the X-axis movable support platform 210 is provided, slidingly engaging with the X-axis guide rails 29. The second slider and the second toothed plate 28 are fixed to the bottom of the X-axis moving support platform 210 parallel to the X-axis guide rail 29. The second drive motor 26 is fixedly installed on the Y-axis moving support platform 25. The second drive gear 27 is fixedly connected to the output shaft of the second drive motor 26 and meshes with the second toothed plate 28 to drive the X-axis moving support platform 210 to reciprocate along the X-axis direction. The clamping mechanism 3 includes a receiving groove opened on the upper surface of the X-axis moving support platform 210 and a clamping drive cylinder installed on the side of the X-axis moving support platform 210. The output end of the clamping drive cylinder is connected to a detachable clamping block through a swing arm type clamping transmission mechanism. The detachable clamping block is used to clamp and lock the mounting base 41 in the receiving groove. The Y-axis and X-axis drive units adopt a combination of motor, gear, toothed plate and guide rail slider to ensure that the moving support platform moves smoothly and accurately in its respective directions, with high positioning accuracy, which can meet the position adjustment requirements of high-precision riveting. The cooperation between the guide rail and the slider improves the stability and straightness of the movement, while the gear and toothed plate transmission provides reliable power transmission. The clamping mechanism 3 is designed to be simple and reliable to operate. It can quickly clamp and release the mounting base 41 through cylinder drive. The detachable clamping block can be replaced according to the shape of different mounting bases 41, which enhances the versatility of the clamping mechanism 3 and ensures the stability of the bottom mold mechanism 4 during position adjustment and riveting, preventing displacement that could affect riveting accuracy.

[0028] In a preferred embodiment, the first posture adjustment mechanism 42 includes a first lifting drive unit, a first rotary drive unit, and a support groove 4212. The fixed end of the first lifting drive unit is mounted on the mounting base 41, and the output end of the first lifting drive unit is connected to the first rotary drive unit to drive the first rotary drive unit to lift along the Z-axis. The output end of the first rotary drive unit is connected to the support groove 4212 to drive the support groove 4212 to rotate around a pivot parallel to the X-axis. Multiple lifting riveting bottom molds 43 are arranged and mounted on the support groove 4212 along the X-axis. This design gives the bottom mold assembly the ability to lift in the Z-axis direction and rotate around the X-axis, allowing the bottom mold to better adapt to the surfaces of workpieces 6 to be riveted at different heights and tilt angles. Through this posture adjustment, the adaptability to workpieces with complex shapes can be improved, ensuring that the bottom mold and the workpiece surface are closely fitted, providing stable support for riveting, thereby improving the stability and quality of riveting and expanding the application range of the equipment in complex spatial posture areas.

[0029] In a preferred embodiment, the first lifting drive unit includes a lifting hydraulic cylinder 421, a vertical guide plate 422, and a lifting plate 423. The cylinder body of the lifting hydraulic cylinder 421 is fixedly mounted on the mounting base 41. The vertical guide plate 422 is fixedly mounted on the mounting base 41 along the Z-axis. A guide sleeve that slides with the vertical guide plate 422 is fixedly provided at the end of the lifting plate 423. The top end of the piston rod of the lifting hydraulic cylinder 421 is fixedly connected to the lifting plate 423. The first rotary drive unit is mounted on the lifting plate 423. The first rotary drive unit includes a support column 424, a mounting side plate 425, a first rotary drive motor 426, a support shaft 427, a first driving wheel 428, a first driven wheel 429, a brake friction pad 4210, and a brake disc 4211. The support column 424 is vertically fixedly connected to the lifting plate 423. One end of the support shaft 427 is fixedly connected to the support column 424. The top end of 24 is rotatably connected to the bearing groove 4212. The mounting side plate 425 is fixedly connected to one end of the bearing groove 4212. The first rotary drive motor 426 is mounted on the mounting side plate 425. The first driving wheel 428 is fixedly connected to the output shaft of the first rotary drive motor 426. The first driven wheel 429 is fixedly sleeved on the outer periphery of the support shaft 427. The first driving wheel 428 and the first driven wheel 429 mesh and drive each other. The brake disc 4211 is sleeved and fixedly mounted on the support shaft 427. The brake friction pad 4210 is correspondingly mounted on the mounting side plate 425. The first lifting drive unit uses the lifting hydraulic cylinder 421 to provide stable lifting power. The vertical guide plate 422 and the guide sleeve ensure the straightness and stability of the lifting process, so that the first rotary drive unit and the bearing groove 4212 can accurately lift and lower in the Z-axis direction, improving the accuracy of the Z-axis position adjustment. The first rotary drive unit achieves the rotation of the bearing groove 4212 around the X-axis through motor-driven gear transmission. The brake friction pad 4210 and brake disc 4211 can be locked after rotating to a suitable angle to ensure the stability of the bottom mold posture during riveting, improve the control accuracy of the rotation angle around the axis, and thus more accurately adapt to the workpiece surface with different tilt angles, further improving the riveting quality.

[0030] In a preferred embodiment, the lifting riveting bottom mold 43 includes: a mounting base 431, a first lifting drive motor 432, a first ball screw pair 433, a lifting output plate 434, a bottom mold body 435, a heating element 436, and a temperature measuring element 437. The mounting base 431 is detachably fixed in the bearing groove 4212. The first lifting drive motor 432 is mounted in the mounting base 431. The first ball screw pair 433 is connected to the output end of the first lifting drive motor 432 along the Z-axis direction. The lifting output plate 434 is fixedly connected to the screw nut of the first ball screw pair 433. A guide key extending along the Z-axis is provided on the mold 31. The lifting output plate 434 slides with the guide key. The bottom mold body 435 is fixedly installed on the top of the lifting output plate 434. The top of the bottom mold body 435 is provided with a forming cavity 4351 that matches the riveting joint 511. The heating element 436 and the temperature measuring element 437 are both located inside the bottom mold body 435 or adjacent to the forming cavity 4351. The design of the lifting riveting bottom mold 43 enables independent and precise lifting and lowering adjustment of the bottom mold body 435 in the Z-axis direction through the first lifting drive motor 432 and the first ball screw pair 433. The guide key ensures the straightness of the lifting. The setting of the heating element 436 and the temperature measuring element 437 can heat the riveting area and monitor the temperature in real time. For brittle or low-ductility materials such as die-cast magnesium and multi-material laminated structures, heating can improve the plasticity and ductility of the material, reduce the deformation resistance, inhibit crack generation, improve forming stability, and significantly improve the riveting quality. The detachable mounting base 431 allows for easy replacement of different specifications of the lifting riveting bottom mold 43 according to different workpiece requirements, enhancing the versatility of the equipment.

[0031] In a preferred embodiment, the guide key includes a guide connecting plate and a lifting guide optical shaft. The guide connecting plate is fixed above the mounting base 431. The top end of the lifting guide optical shaft is fixedly connected to the lifting output plate 434, and the bottom end passes through the guide connecting plate and slides with it to ensure the stability of the lifting output plate 434 during the lifting process and to prevent the bottom mold body 435 from deflecting and affecting the riveting accuracy.

[0032] In a preferred embodiment, a transmission coupling is also included. The first lifting drive motor 432 is connected to the screw end of the first ball screw pair 433 through the transmission coupling to ensure the smoothness of power transmission, reduce the impact of different shaft installations on transmission accuracy, and improve the accuracy and stability of lifting adjustment.

[0033] In a preferred embodiment, the lifting riveting bottom mold 43 further includes a pressure sensor 438. The pressure sensor 438 is disposed on the force transmission path between the lifting output plate 434 and the bottom mold body 435, and is used to collect pressure signals in real time during the riveting process. The pressure sensor 438 can monitor pressure changes in real time during the riveting process, providing an important basis for judging the riveting quality. By analyzing the pressure signal, abnormalities in the riveting process can be detected in a timely manner, such as excessive or insufficient pressure, so that operators can take corresponding measures to adjust in time, ensuring the stability and consistency of riveting quality, which is conducive to timely identification of abnormal riveting points and ensuring the quality of mass production.

[0034] In a preferred embodiment, the second posture adjustment mechanism includes a second lifting drive unit and a second rotation drive unit. The fixed end of the second lifting drive unit is mounted on the worktable 1, and its output end is connected to the second rotation drive unit, driving the second rotation drive unit to move up and down along the Z-axis. The output end of the second rotation drive unit is connected to the rivet joint 511, enabling the rivet joint 511 to rotate around a shaft parallel to the X-axis, adjusting the riveting angle of the rivet joint 511. This mechanism achieves the lifting and lowering of the rivet joint 511 in the Z-axis direction and the rotation adjustment around the X-axis direction, allowing the rivet joint 511 to better match the riveting points at different positions and angles on the bottom mold, improving the accuracy and success rate of riveting. By precisely adjusting the posture and position of the rivet joint 511, riveting defects caused by misalignment between the rivet joint 511 and the riveting points can be effectively avoided, meeting the riveting requirements of various complex-shaped workpieces and improving riveting quality and production efficiency.

[0035] In a preferred embodiment, the second lifting drive unit includes a lifting guide column 51, a second lifting drive motor 52, a second ball screw pair 53, and a lifting slide 54. The lifting slide 54 slides in cooperation with the lifting guide column 51 in the Z-axis direction. The second lifting drive motor 52 is mounted on the bottom of the lifting guide column 51. The second ball screw pair 53 is connected to the output end of the second lifting drive motor 52 along the Z-axis direction. The lifting slide 54 is fixedly connected to the screw nut of the second ball screw pair 53. The second rotary drive unit includes a support plate 55, a second rotary drive motor 56, a rotary transmission shaft 57, a second driving wheel 58, a second driven wheel 59, and a mounting base 510. The support plate 55 is mounted on the lifting slide 54. The rotary transmission shaft 57 is connected to the support plate 55. The second rotary drive motor 56 is mounted on the support plate 54. On plate 55, a second driving wheel 58 is fixedly connected to the output shaft of the second rotary drive motor 56, and a second driven wheel 59 is fixedly sleeved on the outer circumference of the rotary transmission shaft 57. The second driving wheel 58 and the second driven wheel 59 mesh and drive each other. A mounting base 510 is fixedly connected to the middle of the rotary transmission shaft 57, and a rivet head 511 is fixedly mounted on the mounting base 510. It can rotate synchronously with the rotary transmission shaft 57 to adjust the riveting angle. A through slot is provided at the corresponding position of the lifting slide 54 and the mounting base 510. The through slot is used to allow the rivet head 511 to pass through and avoid the rotation stroke of the rivet head 511. The second lifting drive unit drives the ball screw pair through the motor to realize the smooth lifting and lowering of the lifting slide 54 in the Z-axis direction, providing precise control for the height adjustment of the rivet head 511 and ensuring that the rivet head 511 can accurately reach the height position of the riveting point. The second rotary drive unit drives the gear transmission through the motor to realize the rotation of the rivet head 511 around the X-axis direction, and precisely adjusts the riveting angle. The through-hole design avoids interference between the lifting slide 54 and the mounting base 510 and the rotation of the rivet joint 511, ensuring the flexibility and stability of the rotation of the rivet joint 511, improving the accuracy and reliability of the riveting angle adjustment, and further improving the riveting quality and the adaptability of the equipment.

[0036] Example 2 This embodiment provides a method for using a self-piercing riveting device, including the following steps: Step 1: Bottom mold reconstruction and assembly: According to the size and rivet point distribution of the workpiece 6 to be riveted, select the corresponding number of lifting riveting base molds 43, arrange the mounting bases 431 of each lifting riveting base mold 43 along the X-axis direction and fix them in the preset mounting positions in the bearing groove 4212 to form a reconfigurable base mold array; then place the assembled base mold mechanism 4 into the receiving groove on the upper surface of the X-axis moving bearing platform 210, so that the mounting base 41 is in contact with the positioning surface of the receiving groove; start the clamping drive cylinder, the output end of the clamping drive cylinder extends, and drives the detachable clamping block to swing and press down through the swing arm type clamping transmission mechanism, clamping and locking the mounting base 41 in the receiving groove, thus completing the quick clamping and positioning of the base mold mechanism 4.

[0037] Step Two: Workpiece Placement and Initial Alignment Place the workpiece 6 to be riveted above the bottom mold mechanism 4, so that the riveting area is initially aligned with the forming cavity 4351 at the top of the bottom mold body 435 of the corresponding lifting riveting bottom mold 43; the placement position of the workpiece on the bottom mold mechanism 4 can be adjusted as needed according to the actual size and shape of the workpiece.

[0038] Step 3: Precisely align the riveting points: Activate the planar position adjustment mechanism 2: First, activate the first drive motor 21 of the Y-axis drive unit. The first drive motor 21 drives the first drive gear 22 to rotate. The first drive gear 22 meshes with the first toothed plate 23 fixed to the bottom of the Y-axis moving support platform 25, driving the Y-axis moving support platform 25 and its components to move along the Y-axis guide rail 24 to the target position in the Y-axis direction. Then, activate the second drive motor 26 of the X-axis drive unit. The second drive motor 26 drives the second drive gear 27 to rotate. The second drive gear 27 meshes with the second toothed plate 28 fixed to the bottom of the X-axis moving support platform 210, driving the X-axis moving support platform 210 and its bottom mold mechanism 4 to move along the X-axis guide rail 29 to the target position in the X-axis direction. Through the linkage of the X-axis and Y-axis, the target riveting point is precisely aligned with the bottom of the riveting head 511.

[0039] Step 4: Adjusting the side posture and height compensation of the bottom mold: Based on the curved contour of the surface of the workpiece 6 to be riveted, drive the first posture adjustment mechanism 42: First, the first lifting drive unit is driven: the lifting hydraulic cylinder 421 is started, the piston rod of the lifting hydraulic cylinder 421 extends and retracts, driving the lifting plate 423 and the first rotary drive unit and the bearing tank 4212 mounted on it to rise and fall as a whole along the Z-axis direction; during the lifting process, the guide sleeve at the end of the lifting plate 423 slides along the vertical guide plate 422 to guide and constrain the lifting movement, suppress lateral swaying, and make the bearing tank 4212 and multiple lifting riveting bottom molds 43 rise and fall as a whole to the set height.

[0040] Then, the first rotary drive unit is driven as needed: the first rotary drive motor 426 is started, the first rotary drive motor 426 drives the first driving wheel 428 to rotate, the first driving wheel 428 meshes with the first driven wheel 429 fixedly sleeved on the outer periphery of the support shaft 427, driving the bearing groove 4212 to rotate around the support shaft 427 (i.e. around the axis parallel to the X-axis) to a set angle; after rotating to the position, the brake friction pad 4210 rubs and presses against the brake disc 4211 to lock the angle of the bearing groove 4212, so that the support surface of the multiple lifting riveting bottom molds 43 tends to be consistent with the normal direction of the workpiece surface.

[0041] Finally, the independent lifting compensation of each lifting riveting bottom mold 43 is driven: the first lifting drive motor 432 of each lifting riveting bottom mold 43 is started respectively. The first lifting drive motor 432 converts the rotational motion into the linear motion of the lifting output plate 434 through the first ball screw pair 433. The lifting output plate 434 moves along the Z-axis under the guidance of the guide key, driving the bottom mold body 435 fixed at the top of the lifting output plate 434 to lift independently. Through the independent height adjustment of each bottom mold body 435, each forming cavity 4351 is stably attached to the corresponding area of ​​the surface of the workpiece 6 to be riveted, forming a support surface that matches the curved surface contour of the workpiece.

[0042] Step 5: Assisted heating and closed-loop temperature control: The heating element 436 is activated to heat the riveting area. At the same time, the temperature signal of the bottom mold body 435 or the adjacent area of ​​the forming cavity 4351 is collected in real time by the temperature sensing element 437 and fed back to the temperature controller. The temperature controller adjusts the heating power of the heating element 436 according to the deviation between the set temperature and the actual temperature, so that the temperature of the riveting area is stabilized within the preset range, thereby realizing closed-loop temperature control of the riveting area.

[0043] Step Six: Adjusting the Stamping and Riveting Side Posture Activate the second attitude adjustment mechanism: First, drive the second lifting drive unit: Start the second lifting drive motor 52. The second lifting drive motor 52 drives the lifting slide 54 to move along the lifting guide column 51 in the Z-axis direction through the second ball screw pair 53, thereby driving the second rotary drive unit and the rivet joint 511 mounted on the lifting slide 54 to be lifted and lowered as a whole to the set height; Then, drive the second rotary drive unit as needed: Start the second rotary drive motor 56. The second rotary drive motor 56 drives the second drive wheel 58 to rotate. 8 engages with the second driven wheel 59 fixedly sleeved on the outer periphery of the rotary drive shaft 57, driving the rotary drive shaft 57 to rotate. The mounting seat 510 installed in the middle of the rotary drive shaft 57 and the rivet joint 511 fixed on the mounting seat 510 rotate synchronously around the X-axis to a set angle. During the rotation, the rivet joint 511 passes through the through slot provided at the corresponding position of the lifting slide 54 and the mounting seat 510, realizing angle adjustment without interference. Through the above adjustment, the downward pressing direction of the rivet joint 511 is kept consistent with the normal of the point to be riveted.

[0044] Step 7: Self-piercing riveting operation: After the bottom mold side posture adjustment, height compensation and thermal auxiliary heating are completed, and the riveting side posture adjustment is completed, the driving riveting joint 511 is pressed down. The riveting joint 511 presses the rivet into the workpiece 6 to be riveted. In conjunction with the forming cavity 4351 of the lifting riveting bottom mold 43 below, which has completed height adjustment and posture matching, the pressing of the rivet and the expansion of the foot are completed.

[0045] Step 8: Monitoring and Quality Assessment of the Riveting Process During the riveting process, a pressure sensor 438, located on the force transmission path between the lifting output plate 434 and the bottom mold body 435, collects pressure signals in real time. The collected pressure signals are compared with a preset qualified pressure threshold range. If the pressure signal is within the preset threshold range, the riveting quality of the current riveting point is determined to be qualified. If the pressure signal exceeds the preset threshold range (such as insufficient pressure, sudden pressure change, or abnormal peak value), the riveting quality of the current riveting point is determined to be unqualified, and an alarm is issued so that the operator can handle it in time or record and trace it.

[0046] Step Nine: Repeat riveting or replace the bottom mold: If there are multiple riveting points on the workpiece 6 to be riveted, repeat steps three to eight above to complete the riveting operation of the remaining riveting points in sequence; if it is necessary to replace the new workpiece with a different specification or a different riveting point distribution, first loosen the clamping drive cylinder to lift the detachable clamping block, release the mounting base 41, take the original bottom mold mechanism 4 out of the receiving groove, and then reselect the number and layout of the lifting riveting bottom mold 43 according to the needs of the new workpiece, repeat steps one to eight to complete the riveting operation of the new workpiece.

[0047] Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this invention. Furthermore, those skilled in the art will recognize that, based on the ideas of this invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this invention.

Claims

1. A self-piercing riveting device, characterized in that: include: Workbench; A planar position adjustment mechanism is mounted on the worktable and enables the output end of the planar position adjustment mechanism to achieve position movement adjustment in the X-axis and Y-axis directions. A clamping mechanism is installed at the output end of the planar position adjustment mechanism; The bottom mold mechanism includes a mounting base and multiple sets of bottom mold components arranged along the Y-axis. The mounting base is detachably clamped and fixed to the output end of the planar position adjustment mechanism by the clamping mechanism. Each bottom mold component includes a first posture adjustment mechanism and multiple lifting riveting bottom molds. The multiple lifting riveting bottom molds are arranged and installed along the X-axis at the output end of the first posture adjustment mechanism. The first posture adjustment mechanism can drive the multiple lifting riveting bottom molds to rotate around the X-axis and to rise and fall in the Z-axis direction. The lifting riveting bottom molds can be independently adjusted in their own Z-axis direction to adapt to workpieces with different contour surfaces to be riveted. as well as The riveting mechanism includes a second posture adjustment mechanism and a riveting head. The riveting head is installed at the output end of the second posture adjustment mechanism, and the fixed end of the second posture adjustment mechanism is installed on the worktable, positioning the riveting head above the bottom mold mechanism. This allows the attitude and position of the riveting head to be adjusted so that it can be aligned with the riveting points corresponding to different contour curved surfaces. The riveting operation is completed in conjunction with the lifting riveting bottom mold below, which has been adjusted to the corresponding height.

2. The self-piercing riveting device according to claim 1, characterized in that: The planar position adjustment mechanism includes a Y-axis drive unit, a Y-axis moving support platform, an X-axis drive unit, and an X-axis moving support platform. The Y-axis drive unit is mounted on the worktable, and the Y-axis moving support platform is mounted on the output end of the Y-axis drive unit to move along the Y-axis. The X-axis drive unit is mounted on the Y-axis moving support platform, and the X-axis moving support platform is mounted on the output end of the X-axis drive unit to move along the X-axis. The clamping mechanism is fixedly mounted on the X-axis moving support platform.

3. The self-piercing riveting device according to claim 2, characterized in that: The Y-axis drive unit includes a first drive motor, a first drive gear, a first toothed plate, and multiple Y-axis guide rails. The multiple Y-axis guide rails are fixed parallel to each other on the worktable. The bottom of the Y-axis movable support platform is provided with a first slider that slides with the Y-axis guide rails. The first toothed plate is fixed parallel to the Y-axis guide rails at the bottom of the Y-axis movable support platform. The first drive motor is fixedly mounted on the worktable. The first drive gear is fixedly connected to the output shaft of the first drive motor, and the first drive gear meshes with the first toothed plate to drive the Y-axis movable support platform to reciprocate along the Y-axis direction. The X-axis drive unit includes a second drive motor, a second drive gear, a second toothed plate, and multiple X-axis guide rails. The multiple X-axis guide rails are fixed parallel to the Y-axis movable support platform. A second slider that slides with the X-axis guide rails is correspondingly provided at the bottom of the X-axis movable support platform. The second toothed plate is fixed parallel to the X-axis guide rails at the bottom of the X-axis movable support platform. The second drive motor is fixedly mounted on the Y-axis movable support platform. The second drive gear is fixedly connected to the output shaft of the second drive motor, and the second drive gear meshes with the second toothed plate to drive the X-axis movable support platform to reciprocate along the X-axis direction. The clamping mechanism includes a receiving groove formed on the upper surface of the X-direction movable support platform, and a clamping drive cylinder installed on the side of the X-direction movable support platform. The output end of the clamping drive cylinder is connected to a detachable clamping block through a swing arm type clamping transmission mechanism. The detachable clamping block is used to clamp and lock the mounting base in the receiving groove.

4. The self-piercing riveting device according to claim 1, characterized in that: The first attitude adjustment mechanism includes a first lifting drive unit, a first rotary drive unit, and a bearing groove. The fixed end of the first lifting drive unit is mounted on the mounting base. The output end of the first lifting drive unit is connected to the first rotary drive unit to drive the first rotary drive unit to lift along the Z-axis. The output end of the first rotary drive unit is connected to the bearing groove to drive the bearing groove to rotate around a pivot parallel to the X-axis. Multiple lifting riveting bottom molds are arranged and mounted on the bearing groove along the X-axis.

5. The self-piercing riveting device according to claim 4, characterized in that: The first lifting drive unit includes a lifting hydraulic cylinder, a vertical guide plate, and a lifting plate. The cylinder body of the lifting hydraulic cylinder is fixedly installed on the mounting base. The vertical guide plate is fixed on the mounting base along the Z-axis direction. A guide sleeve that slides with the vertical guide plate is fixedly provided at the end of the lifting plate. The top end of the piston rod of the lifting hydraulic cylinder is fixedly connected to the lifting plate. The first rotary drive unit is installed on the lifting plate. The first rotary drive unit includes a support column, a mounting side plate, a first rotary drive motor, a support shaft, a first driving wheel, a first driven wheel, brake friction pads, and a brake disc. The support column is vertically fixedly connected to the lifting plate. One end of the support shaft is fixedly connected to the top of the support column, and the other end is rotatably connected to the bearing groove. The mounting side plate is fixedly connected to one end of the bearing groove. The first rotary drive motor is mounted on the mounting side plate. The first driving wheel is fixedly connected to the output shaft of the first rotary drive motor. The first driven wheel is fixedly sleeved on the outer circumference of the support shaft. The first driving wheel and the first driven wheel mesh and drive each other. The brake disc is sleeved and fixedly mounted on the support shaft. The brake friction pads are correspondingly mounted on the mounting side plate.

6. The self-piercing riveting device according to claim 5, characterized in that: The lifting riveting bottom mold includes: a mounting base, a first lifting drive motor, a first ball screw pair, a lifting output plate, a bottom mold body, a heating element, and a temperature measuring element. The mounting base is detachably fixed to the bearing groove. The first lifting drive motor is installed in the mounting base. The first ball screw pair is connected to the output end of the first lifting drive motor along the Z-axis. The lifting output plate is fixedly connected to the screw nut of the first ball screw pair. The mounting base is provided with a guide key extending along the Z-axis. The lifting output plate is slidably engaged with the guide key. The bottom mold body is fixedly installed on the top of the lifting output plate. The top of the bottom mold body is provided with a forming cavity that matches the riveting head. The heating element and the temperature measuring element are both located in or near the forming cavity of the bottom mold body.

7. The self-piercing riveting device according to claim 6, characterized in that: The lifting riveting bottom mold also includes a pressure sensor, which is set on the force transmission path between the lifting output plate and the bottom mold body, and is used to collect pressure signals in real time during the riveting process.

8. The self-piercing riveting device according to claim 1, characterized in that: The second posture adjustment mechanism includes a second lifting drive unit and a second rotary drive unit. The fixed end of the second lifting drive unit is mounted on the worktable, and the output end is connected to the second rotary drive unit for transmission, driving the second rotary drive unit to move up and down along the Z-axis. The output end of the second rotary drive unit is connected to the rivet joint for transmission, enabling the rivet joint to rotate around a rotating axis parallel to the X-axis, thereby adjusting the riveting angle of the rivet joint.

9. The self-piercing riveting device according to claim 8, characterized in that: The second lifting drive unit includes a lifting guide column, a second lifting drive motor, a second ball screw pair, and a lifting slide. The lifting slide is slidably engaged with the lifting guide column in the Z-axis direction. The second lifting drive motor is installed at the bottom of the lifting guide column. The second ball screw pair is connected to the output end of the second lifting drive motor along the Z-axis direction. The lifting slide is fixedly connected to the screw nut of the second ball screw pair. The second rotary drive unit includes a support plate, a second rotary drive motor, a rotary transmission shaft, a second driving wheel, a second driven wheel, and a mounting base. The support plate is mounted on the lifting slide, the rotary transmission shaft is connected to the support plate, the second rotary drive motor is mounted on the support plate, the second driving wheel is fixedly connected to the output shaft of the second rotary drive motor, the second driven wheel is fixedly sleeved on the outer circumference of the rotary transmission shaft, and the second driving wheel and the second driven wheel mesh and drive each other. The mounting base is fixedly connected to the middle of the rotary transmission shaft, and the rivet head is fixedly mounted on the mounting base and can rotate synchronously with the rotary transmission shaft to adjust the riveting angle. The lifting slide and the mounting base are provided with through slots at corresponding positions. The through slots are used to allow the rivet head to pass through and avoid the rotation stroke of the rivet head.

10. A method of using the self-piercing riveting device as described in any one of claims 1 to 9, characterized in that: Includes the following steps: S1: Based on the size of the workpiece to be riveted and the distribution of the rivet points, select the corresponding number of lifting riveting bottom dies and arrange them along the X-axis direction on the mounting base to form a reconfigurable bottom die array. S2: The mounting base is detachably clamped and fixed to the output end of the planar position adjustment mechanism by means of a clamping mechanism; S3: Place the workpiece to be riveted on the bottom mold mechanism and make the riveting area initially aligned with the forming cavity of the corresponding lifting riveting bottom mold; S4: Activate the planar position adjustment mechanism to move the bottom mold mechanism in the X-axis and Y-axis directions, and accurately align the target riveting point directly below the riveting head; S5: Based on the curved contour of the surface of the workpiece to be riveted, drive the first posture adjustment mechanism to drive multiple lifting riveting bottom dies to rotate around the rotating shaft in the X-axis direction and to lift and lower as a whole in the Z-axis direction, and drive each lifting riveting bottom die to lift and lower independently in its own Z-axis direction, so that the forming cavity of each lifting riveting bottom die is stably attached to the corresponding area of ​​the surface of the workpiece to be riveted. S6: Activate the second attitude adjustment mechanism to adjust the attitude and position of the rivet joint so that the downward pressing direction of the rivet joint is consistent with the normal of the point to be riveted. S7: Drive the rivet head to press down, and cooperate with the lifting rivet bottom mold below which has been adjusted in height to complete the pressing in of the rivet and the forming of the flared foot.

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