A riveting process and laser device for ultra-high strength materials

Abstract

The application provides a riveting process for ultrahigh-strength material, fixes a fastener to be processed on a processing station, aligns a riveting part of the fastener with a light-emitting hole of a laser device, the laser device emits a laser beam, adjusts a propagation path of the laser beam, and matches an irradiation position of the laser beam with a point in the riveting part of the fastener to be processed, the laser device drives the laser beam to rotate, thereby heating a ring-shaped riveting part of the fastener and forming a ring-shaped heating area, after stopping the laser heating, the ring-shaped heating area on the fastener is self-quenched, so that the hardness of the riveting part of the fastener is greater than the hardness of the plate, and the cooled fastener is riveted on the plate, so that the plate and the riveting part of the fastener are connected to form a riveting finished product, the point-shaped laser beam is converted into the ring-shaped laser beam through the rotation refraction unit, the strength and the hardness of the riveting part are enhanced, the riveting process of the ultrahigh-strength plate is adapted, the equipment investment cost is low, and the processing efficiency is greatly improved.

Description

Technical Field

[0001] This application belongs to the technical field of fastener riveting processing, and particularly relates to a riveting process and laser equipment for ultra-high strength materials. Background Technology

[0002] The description in this section provides only background information related to the disclosure of this invention and does not constitute prior art.

[0003] In fields such as machinery manufacturing, aerospace, and automotive, the application of ultra-high strength sheet metal is becoming increasingly widespread, placing extremely high demands on the riveting performance of fasteners. Current technologies primarily employ quenching and tempering or carburizing processes for fastener heat treatment. These processes can only achieve overall performance control of the fastener and cannot achieve localized hardening. This makes it difficult to improve the structural strength of the riveted joint while ensuring the toughness and strength of the threaded connection, thus limiting the riveting adaptability of ultra-high strength sheet metal. Furthermore, existing laser heating and quenching technologies require large equipment such as robotic arms to move the laser heating area during fastener processing. This results in high equipment costs, complex operation, low processing efficiency, and insufficient positioning accuracy, failing to meet the needs of large-scale, high-precision localized annular quenching of fasteners. In summary, existing technologies lack a low-cost, high-efficiency, and precisely positioned localized annular quenching solution for fasteners, making it difficult to adapt to the riveting requirements of ultra-high strength materials.

[0004] It should be noted that the above description of the technical background is only for the purpose of providing a clear and complete explanation of the technical solutions of the present invention and facilitating understanding by those skilled in the art. It should not be assumed that the above technical solutions are known to those skilled in the art simply because they have been described in the background section of this invention. Summary of the Invention

[0005] The purpose of this application is to provide a riveting process and laser equipment for ultra-high strength materials, which solves the problems that existing fastener heat treatment cannot achieve local hardening, and that laser heating quenching is costly and complex to operate.

[0006] This application provides a riveting process for ultra-high strength materials, comprising the following steps: The fastener to be processed is fixed on the processing station, and the riveting part of the fastener is aligned with the light output hole of the laser equipment, wherein the hardness of the plate is greater than the hardness of the fastener. The laser device emits a laser beam and adjusts the propagation path of the laser beam so that the irradiation position of the laser beam matches a point in the annular riveting part of the fastener; The laser device drives the laser beam to rotate, thereby heating the annular riveting part of the fastener to form an annular heating zone; After laser heating is stopped, the annular heating area on the fastener is cooled by self-excited cooling so that the hardness of the riveted part of the fastener is greater than the hardness of the plate. The cooled fastener is riveted onto the plate, so that the plate and the riveted part of the fastener are connected to form a riveted finished product.

[0007] Furthermore, in the aforementioned riveting process for ultra-high strength materials, the laser equipment includes a laser emitting unit and a rotating refraction unit. The rotating refraction unit cooperates with the laser emitting unit to rotate and convert the point laser beam emitted by the laser emitting unit into a ring laser beam.

[0008] Furthermore, in the aforementioned riveting process for ultra-high strength materials, the rotating refraction unit includes a first reflector, a second reflector, a light inlet, a light outlet, and an adjustment structure. The adjustment structure adjusts the angles of the first and second reflectors. The point laser beam emitted by the laser emitting unit enters through the light inlet, undergoes two reflections, and exits through the light outlet. The irradiation position of the laser beam matches the riveting portion of the fastener.

[0009] Furthermore, in the aforementioned riveting process for ultra-high strength materials, the laser power of the laser emitting unit is 800W~1400W, the scanning speed is 1mm / s~10mm / s, and the spot size of the laser beam is 0.2mm~3.0mm.

[0010] Furthermore, in the aforementioned riveting process for ultra-high strength materials, the depth of the hardened layer in the annular heating zone ranges from 0.3 mm to 1.5 mm.

[0011] Furthermore, in the above-mentioned riveting process for ultra-high strength materials, in the step "the laser equipment drives the laser beam to rotate, thereby heating the annular riveting part of the fastener to form an annular heating zone", the laser heating temperature is controlled at 810℃~830℃.

[0012] Furthermore, in the aforementioned riveting process for ultra-high strength materials, the step "after stopping laser heating, cooling the annular heating area on the fastener by self-excited cooling so that the hardness of the riveted part of the fastener is greater than the hardness of the plate" means that the hardness of the riveted part of the fastener reaches 60 HRC or higher after laser heating and cooling.

[0013] Furthermore, in the aforementioned riveting process for ultra-high strength materials, the plate material includes a 1500MPa or 1800MPa strength plate material, and the fastener includes a nut or a bolt.

[0014] Furthermore, in the above-mentioned riveting process for ultra-high strength materials, in the step of "riveting the cooled fastener onto the plate, so that the plate and the riveting part of the fastener are connected to form a riveted finished product", the riveting part of the fastener is provided with multiple anti-rotation ribs, and the hardened anti-rotation ribs penetrate the plate to form an anti-torque structure.

[0015] This application also provides a laser device for implementing the above-mentioned riveting process for ultra-high strength materials, comprising: A laser emitting unit and a rotary refraction unit are arranged sequentially from top to bottom along the axial direction above the fastener. The rotary refraction unit cooperates with the laser emitting unit to convert the dot-shaped light spot emitted by the laser emitting unit into an annular heating zone to perform annular quenching on the riveted part of the fastener. The laser emitting unit is a laser generator capable of emitting laser beams; The rotating refraction unit includes a housing, a light inlet, a first reflector, an adjustment structure, a second reflector, and a light outlet. The light inlet is located at the top of the housing and can accommodate the laser beam. The first and second reflectors are located inside the housing to form the propagation path of the laser beam. The light outlet is located at the bottom of the housing, and the laser beam exits from the light outlet. The adjustment structure is located on the housing and connected to the second reflector for optical path calibration of the laser beam.

[0016] As can be seen from the above technical solution, the present invention has the following beneficial effects: The riveting process for ultra-high strength materials described in this invention replaces traditional robotic arm equipment with a rotating refraction unit, converting a point laser beam into a ring-shaped heating zone. This eliminates the need for complex equipment movement control, resulting in low equipment investment costs and significantly improved processing efficiency. Furthermore, by setting parameters such as laser power, it can adapt to the laser heating requirements of fasteners of different specifications, demonstrating strong versatility. It achieves localized and precise ring-shaped laser heating and strengthening of the riveted part of the fastener, enhancing the strength and hardness of the riveted part. It is suitable for riveting processing of ultra-high strength plates of different grades, while reducing equipment investment and processing costs and improving processing efficiency. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 and Figure 2This is a schematic diagram of a laser device for implementing a riveting process for ultra-high strength materials, provided in an embodiment of this application. Figure 3 This is a schematic diagram of the conversion of a point laser beam into a ring-shaped heating zone at the riveting part of the fastener provided in this application embodiment; Figure 4 This is a schematic diagram of a nut product provided in this application embodiment that can be used for riveting ultra-high strength plates at 1800MPa. Figure 5 This is a schematic diagram of a nut fastener that can be used for riveting ultra-high strength plates up to 1500MPa, provided in an embodiment of this application. Figure 6 This is a schematic diagram of the installation of fasteners and plates provided in the embodiments of this application; Figure 7 This is an installation diagram illustrating the riveting of the mold auxiliary fasteners to the sheet metal provided in the embodiments of this application; Figure 8 This is a practical diagram of the riveted state provided in the embodiments of this application.

[0019] In the picture: 1. Fasteners; 11. Riveting joints; 12. Anti-rotation ribs; 2. Laser emitting unit; 21. Laser beam; 22. Annular heating zone; 3. Rotating refraction unit; 31. Light inlet aperture; 32. Light outlet aperture; 33. First reflecting mirror; 34. Second reflecting mirror; 35. Adjustment structure; 4. Board material. Detailed Implementation

[0020] To enable those skilled in the art to better understand the technical solutions in this application, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this application.

[0021] In the description of this invention, it should be noted that the terms "upper," "middle," "lower," "inner," "outer," "front," and "rear," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. The terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances. The embodiments of this invention will now be described according to its overall structure.

[0022] Example Reference Figures 1 to 8 This application provides a riveting process for ultra-high strength materials, including the following steps: The fastener 1 to be processed is fixed on the processing station, so that the riveting part 11 of the fastener 1 is aligned with the light output hole 32 of the laser equipment. The hardness of the plate 4 is greater than that of the fastener 1. Ensure that the annular heating zone 22 accurately covers the riveting part 11 of the fastener 1. The laser device emits a laser beam 21 and adjusts the propagation path of the laser beam 21 so that the irradiation position of the laser beam 21 matches a point in the riveting part 11 of the fastener 1. The laser device drives the laser beam 21 to rotate, thereby heating the annular riveting part 11 of the fastener 1 to form an annular heating area 22; After laser heating is stopped, the annular heating area 22 on the fastener 1 is cooled by self-excited cooling so that the hardness of the riveting part 11 of the fastener 1 is greater than the hardness of the plate 4. The cooled fastener 1 is riveted onto the plate 4, so that the plate 4 and the riveting part 11 of the fastener 1 are connected to form a riveted finished product. Inspect the riveted finished product. Confirm that the hardened area of ​​the fastener 1 only bears pressure, the threaded connection area is not affected by laser hardening, and maintains the toughness and strength that meet the requirements of fastener 1 grade.

[0023] Self-excited cooling refers to a surface modification technique in which a high-energy laser beam rapidly heats the surface of a metal material during laser quenching, causing the surface temperature to rise rapidly above the phase transition point (below the melting point). After the laser beam leaves, the heated surface cools rapidly by conducting its own heat, thus completing the phase transformation hardening process.

[0024] In this embodiment, the laser device is driven to rotate and adopts a laser self-excited cooling method, which does not require cooling media such as water or oil. The processing is clean and pollution-free, and the cooling speed is fast with high quenching efficiency. At the same time, the device can realize multi-station synchronous operation, further improving the efficiency of large-scale production. The annular heating zone 22 after laser heating is only used for riveting and bearing pressure. Although it has high hardness and certain brittleness, it is not subjected to tensile and shear stress in actual use, so it is safe to use. Other areas of the fastener 1 bear the functions of support and threaded connection, maintaining the original toughness and strength, so that the overall riveting structure has both high strength and high stability.

[0025] Specifically, in this embodiment, the laser device includes a laser emitting unit 2 and a rotating refraction unit 3. The rotating refraction unit 3 cooperates with the laser emitting unit 2 to rotate and convert the point laser beam emitted by the laser emitting unit 2 into a ring laser beam. The laser beam 21 emitted by the laser emitting unit 2 is on the same axis as the axis of the fastener 1, and the laser beam 21 rotates and heats in a ring around the axis of the fastener 1.

[0026] Specifically, in this embodiment, the rotating refraction unit 3 includes a first reflector 33, a second reflector 34, a light inlet 31, a light outlet 32, and an adjustment structure 35. The adjustment structure 35 adjusts the angles of the first reflector 33 and the second reflector 34. The point laser beam 21 emitted by the laser emitting unit 2 enters through the light inlet 31, and after two reflections, exits through the light outlet 32. The irradiation position of the laser beam 21 matches the riveting part 11 of the fastener 1.

[0027] Specifically, in this embodiment, the laser power of the laser emitting unit 2 is 800W~1400W, the scanning speed is 1mm / s~10mm / s, and the spot size of the laser beam is 0.2mm~3.0mm.

[0028] Specifically, in this embodiment, the hardened layer depth of the annular heating zone 22 ranges from 0.3mm to 1.5mm.

[0029] Specifically, in this embodiment, in the step "the laser device drives the laser beam 21 to rotate, thereby heating the annular riveting part 11 of the fastener 1 to form an annular heating area 22", the laser heating temperature is controlled at 810℃~830℃.

[0030] Specifically, in this embodiment, after stopping laser heating, the annular heating area 22 on the fastener 1 is cooled by self-excited cooling so that the hardness of the riveting portion 11 of the fastener 1 is greater than that of the plate 4. After laser heating, the hardness of the riveting portion 11 of the fastener 1 reaches 60 HRC or higher. The fastener 1 is made of medium carbon steel or alloy steel. During the cooling process, the annular heating area 22 of the fastener 1 undergoes a microstructure transformation, resulting in increased strength and increased hardness.

[0031] Specifically, in this embodiment, the plate 4 includes a 1500MPa or 1800MPa strength plate 4, and the fastener 1 includes a nut or bolt. The hardness of the quenched area of ​​medium carbon steel or alloy steel can reach above 60HRC, which can be adapted to riveting of ultra-high strength plates 4 of different grades such as 1500MPa and 1800MPa. Furthermore, the riveting torsional performance with ultra-high strength plates 4 can be further improved by adjusting the torsional structure to a tendon structure.

[0032] Specifically, in this embodiment, in the step of "riveting the cooled fastener 1 onto the plate 4, so that the plate 4 and the riveting part 11 of the fastener 1 are connected to form a riveted finished product", the riveting part 11 of the fastener 1 is a tendon structure with multiple anti-rotation ribs 12, and the hardened anti-rotation ribs 12 penetrate the plate 4 to form an anti-torque structure.

[0033] By utilizing the aforementioned riveting process, the rotating refraction unit 3 replaces the traditional robotic arm equipment, converting the point laser beam into a ring-shaped heating zone 22. This eliminates the need for complex equipment movement control, resulting in low equipment investment costs and significantly improved processing efficiency. Furthermore, by setting parameters such as laser power, it can adapt to the laser heating requirements of fasteners 1 of different specifications, demonstrating strong versatility. It achieves precise ring-shaped laser heating and strengthening of the riveting part 11 of the fastener 1. The laser beam has high directivity, and with the optical path adjustment structure 35 and precise positioning of the fastener 1, it can achieve precise local ring-shaped laser heating of the key riveting parts of the fastener 1. Moreover, the through-hole control of the laser beam scanning speed of 1mm / s~10mm / s ensures that the heating temperature is stable at 810℃~830℃, guaranteeing uniform laser heating structure. Based on the characteristic that laser time and power are proportional to quenching depth, the hardened layer depth of the ring-shaped heating zone 22 can be precisely controlled from 0.3mm to 1.5mm. The laser heating area is completely isolated from the threaded connection area, ensuring the toughness and strength of the threaded area. Employing a laser self-excited cooling method, this system eliminates the need for cooling media such as water or oil, resulting in a clean and pollution-free processing method with rapid cooling and high quenching efficiency. Furthermore, the equipment allows for multi-station simultaneous operation, further enhancing large-scale production efficiency. During the cooling process, the annular heating zone 22 of the fastener 1 undergoes a microstructural transformation, resulting in increased strength and hardness. This allows it to be adapted for riveting different grades of ultra-high strength sheet metal, and the enhanced strength of the riveted portion further improves the torsional resistance of the riveting with ultra-high strength sheet metal.

[0034] The strength and hardness of fasteners significantly improved after laser heating and self-excited cooling. The core reason is that this process induces a phase transformation in the metallographic structure of the heated area of ​​the fastener, from pearlite and ferrite to martensite. Simultaneously, the rapid heating and cooling characteristics of laser heating preserve the fine-grained structure of the material. Combined with stress optimization through localized processing, this ultimately leads to a substantial improvement in mechanical properties. In this embodiment, the laser self-excited cooling is an air cooling method without an external cooling medium (water / oil). However, due to the localization of laser heating and the difference in thermal gradient, the cooling rate still reaches the critical cooling rate for the martensitic phase transformation of medium carbon steel, which is the core of the strength improvement. The essence of martensitic phase transformation: Under ultra-rapid cooling, supersaturated austenite cannot decompose into ferrite and pearlite through diffusion, but instead undergoes a diffusionless shear phase transformation. Carbon atoms are forced to remain in the body-centered cubic lattice of iron, forming a supersaturated solid solution—martensite. The lattice of martensite is severely distorted, which produces strong solid solution strengthening and lattice distortion strengthening, resulting in a sharp increase in the hardness and strength of the material (the hardness of medium carbon steel martensite can reach over 60 HRC, far exceeding that of the original microstructure).

[0035] Advantages of self-excited cooling process: In this invention, the quenching area is only a local annular area of ​​the fastener. A huge temperature difference is formed between the heated area and the unheated area (thread / support area). Heat is quickly conducted to the unheated area, naturally achieving ultra-fast cooling. This cooling method has no medium pollution, and the cooling rate can be controlled by laser power and scanning time (proportional to quenching depth), precisely controlling the degree of martensitic transformation and avoiding cracking caused by over-quenching.

[0036] In this embodiment, laser heating is applied only to the annular area of ​​the fastener riveting joint, and this area only bears pressure in actual use, not tensile / shear stress. This design allows for the reasonable release of phase transformation stress while avoiding the stress defects of overall quenching. Local phase transformation stress is controllable: Overall quenching causes the material to undergo a martensitic phase transformation, generating huge structural and thermal stresses, which can easily lead to deformation and cracking of fasteners; while local annular quenching has a small phase transformation area, and the stress can be released through the untransformed matrix (original structural area), forming only slight compressive stress in the quenching area, which can improve the compressive strength of the riveting part.

[0037] The brittleness of martensite is reasonably avoided: Although martensite has high hardness and strength, it has poor plasticity and toughness and is brittle; however, in this invention, the quenched area is only used for riveting (pure compressive stress condition) and does not need to bear tensile or shear forces, so its brittleness will not affect the safety of use. At the same time, the unquenched thread / support area retains the original ferrite + pearlite structure, ensuring the toughness of the fastener and the thread connection performance, and achieving the performance matching of "hard area anti-riveting and soft area anti-torsional / tensile".

[0038] The process in this embodiment utilizes the strengthening and toughening effect of martensitic phase transformation and solves the deformation and cracking problems of overall heating of medium carbon steel through the precise processing characteristics of laser. At the same time, it achieves the performance zoning of fasteners with "high strength at the riveting part and high toughness at the threaded part", perfectly adapting to the riveting requirements of ultra-high strength plates.

[0039] This application embodiment also provides a laser device for the above-mentioned riveting process of ultra-high strength materials, including: A laser emitting unit 2 and a rotating refraction unit 3 are arranged sequentially from top to bottom along the axial direction above the fastener 1. The rotating refraction unit 3 cooperates with the laser emitting unit 2 to convert the dot-shaped light spot emitted by the laser emitting unit 2 into an annular heating zone 22, and performs annular quenching on the riveting part 11 of the fastener 1. The laser emitting unit 2 is a laser generator capable of emitting a laser beam 21; The rotating refraction unit 3 includes a housing, a light inlet 31, a first reflector 33, an adjustment structure 35, a second reflector 34, and a light outlet 32. The light inlet 31 is located at the top of the housing and can accommodate the laser beam. The first reflector 33 and the second reflector 34 are located inside the housing to form the propagation path of the laser beam. The light outlet 32 ​​is located at the bottom of the housing, and the laser beam exits from the light outlet 32. The adjustment structure 35 is located on the housing and connected to the second reflector 34 for optical path calibration of the laser beam.

[0040] In this embodiment, the laser emitting unit 2 is a fixed laser generator that can emit a point laser beam with a power of 800W~1400W. The laser beam has high directivity and a small divergence angle, and the emitted point spot size is 0.2mm~3.0mm. The rotating refraction unit 3 can be driven to rotate, causing the point laser beam to rotate and be converted into an annular laser beam at the riveting part 11 of the fastener 1, forming an annular heating zone 22. The heating temperature is stable at 810℃~830℃. The annular heating zone 22 can accurately cover the key riveting parts of the fastener 1. The annular heating zone formed after heating is only used for the riveting operation of the fastener 1. In actual use, it only bears pressure and is not subjected to tension or shear stress. The emission power and spot size of the laser emitting unit 2, as well as the rotation speed of the laser beam driven by the rotating refraction unit 3, can be flexibly adjusted according to the specifications and heating depth requirements of the fastener 1, adapting to the local annular laser heating processing of fasteners 1 of different types and specifications; the laser equipment can realize multi-station synchronous operation, and multiple rotating refraction units 3 cooperate with the laser emitting unit 2 to simultaneously perform local annular laser heating processing of the riveting part 11 of multiple fasteners 1, adapting to the large-scale processing requirements of riveting technology.

[0041] Example 1 Fix the medium carbon steel nut at the machining station; The fixed laser generator and rotating refraction unit 3 are placed on top of the nut. The angle of the second reflector 34 is adjusted by adjusting structure 35 to complete the optical path calibration. The laser generator is started, and a laser beam with a power of 800W and a spot size of 0.5mm is emitted precisely from the light exit hole 32 after passing through the light inlet 31, the first reflector 33, and the second reflector 34. The rotating refraction unit 3 drives the laser beam to perform a ring-shaped rotating laser on the riveting part 11 of the nut, forming a ring-shaped heating zone 22 in the riveting part 11, stabilizing the heating temperature at 810℃. Based on the characteristic that the scanning time and power are proportional to the quenching depth, the laser irradiation time is set to 5s, and the hardened layer depth is controlled to be 0.8mm. The laser irradiation is stopped, and the ring-shaped heating zone 22 of the nut is naturally cooled by laser self-excited cooling. After cooling, the hardness of the ring area of ​​the riveting part 11 is measured to be 60HRC. The quenched nut (reference) Figure 5The nut was directly riveted to the 1500Mpa high-strength plate 4. After the riveting was completed, the toughness and strength of the nut thread area were not affected by the laser heating and met the requirements of fastener 1. The annular heating zone 22 only bears compressive stress. The torsional and tensile properties of the riveted structure meet the working conditions of the 1500Mpa ultra-high-strength plate 4.

[0042] Example 2 Fix the medium carbon steel nut at the machining station; The fixed laser generator and rotating refraction unit 3 are placed on top of the nut. The angle of the second reflector 34 is adjusted by adjusting structure 35 to complete the optical path calibration. The laser generator is started, and a laser beam with a power of 1400W and a spot size of 2.0mm is emitted precisely from the light exit hole 32 after passing through the light inlet 31, the first reflector 33, and the second reflector 34. The rotating refraction unit 3 drives the laser beam to perform a ring-shaped rotating laser on the riveting part 11 of the nut, forming a ring-shaped heating area 22 in the riveting part 11, stabilizing the heating temperature at 830℃. Based on the characteristic that the scanning time and power are proportional to the quenching depth, the laser irradiation time is set to 5s, and the hardened layer depth is controlled to 1.2mm. The laser irradiation is stopped, and the ring-shaped heating area 22 of the nut is naturally cooled by laser self-excited cooling. After cooling, the hardness of the ring area of ​​the riveting part 11 is measured to be 63HRC. Using a mold-assisted method, the cooled nut is riveted at 1800Mpa (reference). Figure 4 On the ultra-high strength plate 4, the tendon structure of the nut riveting part 11 is inserted into the plate 4 to form a reliable anti-torsion function; after the riveting is completed, the toughness and strength of the nut thread area meet the requirements of fastener 1, the riveting structure is not loose or deformed, and meets the use requirements. The riveting part 11, which has been annularly heated, is riveted to the 1800MPa high strength plate 4 to form a riveted product.

[0043] Although different specific embodiments are mentioned in this application, this application is not limited to the situations described in industry standards or embodiments. Slightly modified implementations based on certain industry standards or custom methods or embodiments can also achieve the same, equivalent, or similar, or predictable, implementation effects as the above embodiments. Embodiments applying these modified or modified data acquisition, processing, output, and judgment methods still fall within the scope of optional implementations of this application.

[0044] Although this application has been described through embodiments, those skilled in the art will recognize that many modifications and variations are possible without departing from the spirit of this application, and it is intended that the appended embodiments include these modifications and variations without departing from this application.

Claims

1. A riveting process for ultra-high strength plates, characterized in that, Includes the following steps: The fastener to be processed is fixed on the processing station, and the riveting part of the fastener is aligned with the light output hole of the laser equipment, wherein the hardness of the plate is greater than the hardness of the fastener. The laser device emits a laser beam and adjusts the propagation path of the laser beam so that the irradiation position of the laser beam matches a point in the annular riveting part of the fastener; The laser device drives the laser beam to rotate, thereby heating the annular riveting part of the fastener to form an annular heating zone; After laser heating is stopped, the annular heating area on the fastener is cooled by self-excited cooling so that the hardness of the riveted part of the fastener is greater than the hardness of the plate. The cooled fastener is riveted onto the plate, so that the plate and the riveted part of the fastener are connected to form a riveted finished product.

2. The riveting process for ultra-high strength materials according to claim 1, characterized in that, The laser device includes a laser emitting unit and a rotating refraction unit. The rotating refraction unit works in conjunction with the laser emitting unit to rotate and convert the point laser beam emitted by the laser emitting unit into a ring laser beam.

3. The riveting process for ultra-high strength materials according to claim 2, characterized in that, The rotating refraction unit includes a first reflector, a second reflector, a light inlet, a light outlet, and an adjustment structure. The adjustment structure adjusts the angles of the first and second reflectors. The point laser beam emitted by the laser emitting unit enters through the light inlet, is reflected twice, and exits through the light outlet. The irradiation position of the laser beam matches the riveting part of the fastener.

4. The riveting process for ultra-high strength materials according to claim 2, characterized in that, The laser emitting unit has a laser power of 800W~1400W, a scanning speed of 1mm / s~10mm / s, and a laser beam spot size of 0.2mm~3.0mm.

5. The riveting process for ultra-high strength materials according to claim 1, characterized in that, The hardened layer depth of the annular heating zone ranges from 0.3 mm to 1.5 mm.

6. The riveting process for ultra-high strength materials according to claim 1, characterized in that, In the step "the laser device drives the laser beam to rotate, thereby heating the annular riveting part of the fastener to form an annular heating zone", the laser heating temperature is controlled at 810℃~830℃.

7. The riveting process for ultra-high strength materials according to claim 1, characterized in that, After stopping laser heating, the annular heating area on the fastener is cooled by self-excited cooling so that the hardness of the riveted part of the fastener is greater than that of the plate. After laser heating, the hardness of the riveted part of the fastener reaches 60 HRC or higher.

8. The riveting process for ultra-high strength materials according to claim 1, characterized in that, The plate material includes 1500MPa or 1800MPa strength plate material, and the fasteners include nuts or bolts.

9. The riveting process for ultra-high strength materials according to claim 1, characterized in that, In the step "riveting the cooled fastener to the plate, so that the plate and the riveting part of the fastener are connected to form a riveted finished product", the riveting part of the fastener is provided with multiple anti-rotation ribs, and the hardened anti-rotation ribs penetrate the plate to form an anti-torque structure.

10. A laser device for implementing the riveting process for ultra-high strength materials as described in any one of claims 1-9, characterized in that, include: A laser emitting unit and a rotary refraction unit are arranged sequentially from top to bottom along the axial direction above the fastener. The rotary refraction unit cooperates with the laser emitting unit to convert the dot-shaped light spot emitted by the laser emitting unit into an annular heating zone to perform annular quenching on the riveted part of the fastener. The laser emitting unit is a laser generator capable of emitting laser beams; The rotating refraction unit includes a housing, a light inlet, a first reflector, an adjustment structure, a second reflector, and a light outlet. The light inlet is located at the top of the housing and can accommodate the laser beam. The first and second reflectors are located inside the housing to form the propagation path of the laser beam. The light outlet is located at the bottom of the housing, and the laser beam exits from the light outlet. The adjustment structure is located on the housing and connected to the second reflector for optical path calibration of the laser beam.

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