High-strength rolling profile with projection welding nut and machining method of high-strength rolling profile

Abstract

A high-strength rolling profile with a projection welding nut is formed by splicing and welding a rolling beam shaped like a Chinese character'ri 'and a C-shaped rolling beam, the whole section of the rolling profile is shaped like a Chinese character'mu', the rolling profile comprises a first cavity, a second cavity and a third cavity which are arranged side by side, and the first cavity and the second cavity are separated through a first middle reinforcing rib; the second cavity and the third cavity are separated through a second middle reinforcing rib, a projection welding nut is welded to a right vertical rib of the third cavity and located in the third cavity, and a pre-punched hole is formed in the position, where the projection welding nut is welded, of the right vertical rib. Before rolling forming of the profile, the projection welding nut welding procedure is added, under the condition that a projection welding nut tool receding hole is not formed, the projection welding nut is welded into a closed cavity rolling section, the section is formed by splicing and welding the C shape and the shape like the Chinese character'ri ', three contact force peak values are generated when three formed cavities collide, the energy absorption efficiency is high, and the service life of the profile is prolonged. The strength and rigidity of the whole section are improved, and the bending resistance is greatly improved.

Description

Technical Field

[0001] The present invention relates to a high-strength roll-formed profile with projection welding nuts and a processing method thereof, belonging to the technical field of automotive profiles. Background Art

[0002] As a major country in automobile production and sales, China's control of carbon emissions is particularly important. Therefore, the country's strong promotion of new energy vehicles is an important direction to reduce carbon emissions. As the core component of electric vehicles, the safety of the battery pack has attracted much attention. The automotive sill plays an extremely important role in protecting the battery shell in side impact and side pole impact regulations during vehicle safety evaluation. The automotive sill includes an inner sill panel, a sill reinforcement, and an outer sill panel. The sill is connected to the battery shell. At present, aluminum profiles are commonly used to make the battery shell. When the vehicle undergoes side impact and side pole impact, it is easy to deform the aluminum profile, resulting in damage to the battery shell, fire, or explosion.

[0003] As the first barrier to protect the battery in side impact and side pole impact accidents, the conventional solution is to use a stamping plate for reinforcement. Generally, the stamping plate has low strength, high material thickness, complex production process, high cost, and large weight, which is not conducive to the lightweight of new energy vehicles. The aluminum profile material has low strength and high cost.

[0004] Currently, profiles are used as reinforcements and fixed between the outer sill panel and the inner sill panel. The fixing method mostly uses projection welding nuts or blind rivet nuts. For traditional closed roll-formed product cavities, if projection welding nuts are installed in the cavity, large tool through-holes need to be opened on the cavity wall, which is complex in process and damages the closed cavity structure and stiffness; while using blind rivet nuts has a higher cost. Summary of the Invention

[0005] In order to overcome the drawbacks of the prior art, the present invention provides a high-strength roll-formed profile with projection welding nuts and a processing method thereof. The roll-formed profile is formed by welding a "day" - shaped roll-formed beam and a "C" - shaped roll-formed beam into an "eye" - shaped profile. Before roll forming, projection welding nuts are welded on the plate, avoiding opening tool relief holes for projection welding nuts on the profile, and realizing welding the projection welding nuts into the closed cavity roll-formed section, which has excellent bending resistance.

[0006] The technical solution adopted by the present invention to solve its technical problems is as follows: A high-strength roll-formed profile with projection welding nuts, the roll-formed profile is formed by welding a "day" - shaped roll-formed beam and a "C" - shaped roll-formed beam, the overall section of the roll-formed profile is an "eye" - shaped, including a first cavity, a second cavity, and a third cavity arranged side by side. The first cavity and the second cavity are separated by a first intermediate reinforcing rib, the second cavity and the third cavity are separated by a second intermediate reinforcing rib, a projection welding nut is welded on the right vertical rib of the third cavity, the projection welding nut is located inside the third cavity, and a pre-punched hole is provided at the position where the projection welding nut is welded on the right vertical rib.

[0007] The above-mentioned high-strength roll-formed profile with projection welding nuts, the "day"-shaped roll-formed beam is a closed structure formed by multiple cold bending of a steel plate, including a first intermediate reinforcing rib, a middle upper horizontal rib, a second intermediate reinforcing rib, a first welding hook edge, a second welding hook edge, a right upper horizontal rib, a right vertical rib, a right lower horizontal rib and a middle lower horizontal rib; the first welding hook edge and the second welding hook edge are respectively welded to the right lower horizontal rib and the second intermediate reinforcing rib; the second intermediate reinforcing rib, the middle upper horizontal rib, the first intermediate reinforcing rib and the middle lower horizontal rib sequentially enclose a second cavity; the right upper horizontal rib, the right vertical rib, the right lower horizontal rib and the second intermediate reinforcing rib enclose a third cavity.

[0008] The above-mentioned high-strength roll-formed profile with projection welding nuts, the "C"-shaped roll-formed beam is formed by multiple cold bending, including a third welding hook edge, a left upper horizontal rib, a left vertical rib, a left lower horizontal rib and a fourth welding hook edge, and the third welding hook edge and the fourth welding hook edge are respectively welded to the top end and the bottom end of the first intermediate reinforcing rib.

[0009] The above-mentioned high-strength roll-formed profile with projection welding nuts, the length of the first welding hook edge ≥ 5 mm, the length of the second welding hook edge ≥ 4 mm, and the lengths of the third welding hook edge and the fourth welding hook edge are both ≥ 4 mm.

[0010] The above-mentioned high-strength roll-formed profile with projection welding nuts, the first cavity is rectangular or trapezoidal, the second cavity is rectangular or irregular, and the third cavity is rectangular or trapezoidal.

[0011] The above-mentioned high-strength roll-formed profile with projection welding nuts, the included angle c formed by the third welding hook edge and the left upper horizontal rib is 30~135°, the included angle f formed by the left lower horizontal rib and the fourth welding hook edge is 30~135°, and the included angles c and f are the same or different; the included angle a formed by the middle upper horizontal rib and the second intermediate reinforcing rib is 30~135°, the included angle b formed by the middle lower horizontal rib and the second intermediate reinforcing rib is 30~135°, and the included angles a and b are the same or different; the included angle d formed by the right upper horizontal rib and the right vertical rib is 30~135°, the included angle e formed by the right lower horizontal rib and the right vertical rib is 30~135°, and the included angles d and e are the same or different; the included angle c ≤ a ≤ d; the included angle f ≤ b ≤ e.

[0012] A processing method for a high-strength roll-formed profile with projection welding nuts, the processing method includes the following steps: S1. Uncoil, level and pre-punch the sheet. S2. Feed the sheet with pre-punched holes into the welding workstation, and multiple welding robots complete the on-line projection welding of nuts. S3. Feed the welded sheet into a cold bending forming machine set for multiple bending formations. Both the second cavity and the third cavity are formed by relative internal winding bending. During processing, first complete the formation of the second cavity, close the second cavity through the first welding, then complete the formation of the third cavity. At the same time, conduct the second welding to close the third cavity and connect the two cavities into one body, forming a "day" - shaped rolled profile with a projection - welded nut. S3. According to the required length, cut and blank the rolled profile to a fixed length. S4. Connect the "C" - shaped rolled beam formed by multiple roll bends to the "day" - shaped rolled profile through welding to form an "eye" - shaped rolled profile.

[0013] For the processing method of the above - mentioned high - strength rolled profile with a projection - welded nut, step S3 is the rolling formation section of the "day" - shaped profile, specifically including the following steps: S31. High - precision formation of some structural features The sheet enters the first cold bending forming machine set. First, simultaneously form and weld the process edges on both sides. At the same time, control the formation of the right - hand top corner of the second cavity through multiple bends and springbacks. Then, simultaneously form the outer top corners of the two cavities on both sides, and use bottom reverse bending to avoid empty bending, keeping the outer top corners on both sides in a solid - pressed state, and form the outer top corners to a certain angle. After that, simultaneously form the outer bottom corners of the two cavities on both sides to a certain angle and flatten the bottom surface. A total of 3 forming passes are made, thus high - precision forming some structural features. S32. Formation of the second cavity First, control the formation of the left - hand bottom corner through multiple bends and springbacks, and at the same time control the formation of the left - hand top corner through multiple bends and springbacks. Secondly, slowly form the right - hand bottom corner and top corner. Through the forming speed difference on both sides, leave a space for the roller to press solid in the middle position to facilitate the closing of the second cavity. When the second cavity is closed, enter the first welding mechanism for the first welding, welding the first welding edge to the lower - right horizontal rib to complete the closing of the second cavity. S33. Formation of the third cavity The profile enters the second cold bending forming machine set. Form the right - hand bottom corner through multiple bends, and at the same time control the formation of the right - hand top corner through springback to complete the closing of the third cavity. When the third cavity is closed, enter the second welding mechanism for the second welding, welding the second welding edge to the second intermediate reinforcing rib of the second cavity to connect the two cavities into one body, forming a closed rolled profile. S34. Precision control For the rolled profile obtained in step S33, first conduct more precise cross - section precision control through a sizing machine set, and then enter step S4.

[0014] The processing method of the above-mentioned high-strength roll-formed profile with projection welded nuts, where the primary welding and secondary welding are arc welding or fusion welding; for the arc welding, tungsten inert gas arc welding, metal inert gas arc welding, carbon dioxide gas shielded arc welding or plasma arc welding is selected, and for the fusion welding, electron beam welding or laser welding is selected.

[0015] The beneficial effects of the present invention are as follows: 1. Before the roll forming of the roll-formed profile of the present invention, a projection welded nut welding process is added, and the projection welded nut is welded into the closed cavity roll-formed section without opening a tool relief hole for the projection welded nut.

[0016] 2. The "eye" shaped section of the present invention is formed by welding a "C" shaped and a "day" shaped roll-formed beam. The three cavities formed generate three contact force peaks during collision, with high energy absorption efficiency. After the two sections are welded together, the strength and stiffness of the overall section are improved, and the bending resistance is greatly enhanced; under the same strength, the structure and process of this roll-formed part are simple, and the cost has more advantages.

[0017] 3. The section of the present invention uses ultra-high-strength steel that can reach 1500 Mpa, with high strength, not easily damaged during collision, better protecting the battery case, improving the safety of the battery case during collision, and having a small material thickness and light weight, with remarkable lightweight results.

[0018] 4. By controlling the angles of the section (angles c, d, a, b, e and f), the deformation sequence is effectively controlled, so that the section satisfies the first cavity deforming first, the second cavity deforming next, and the third cavity deforming last, which helps to control the crushing form.

[0019] 5. The processing method of the present invention is production on a roll-punching line, and the holes required for the roll-formed part are completed online without subsequent processing, with high efficiency. Brief Description of the Drawings

[0020] Figure 1 It is a schematic diagram of the overall structure of the roll-formed profile of the present invention; Figure 2 It is a schematic diagram of the cross-sectional structure of the roll-formed profile in Embodiment 1 of the present invention; Figure 3 It is a schematic diagram of the structure when the profile is installed in the sill; Figure 4 It is a schematic diagram of the forming process flow of the "day" shaped roll-formed beam with projection welded nuts in Embodiment 1; Figure 5 It is a schematic diagram of the equipment connection of the processing production line of the present invention; Figure 6 It is a schematic diagram of the roll wheel die of the "day" shaped roll-formed profile with projection welded nuts; Figure 7 It is a schematic diagram of the cross-sectional structure of the roll-formed profile in Embodiment 2 of the present invention; Figure 8Schematic diagram of the cross-sectional shape of the roll-formed profile in Embodiment 3 of the present invention; Figure 9 Schematic diagram of the cross-sectional shape of the roll-formed profile in Embodiment 4 of the present invention; Figure 10 Schematic diagram of the traditional "mesh" - shaped cross-sectional shape.

[0021] In the figure: 1. First intermediate reinforcing rib; 2. Second intermediate reinforcing rib; 3. Right vertical rib; 4. Projection welding nut; 6. Upper-middle horizontal rib; 7. First welding hook edge; 8. Second welding hook edge; 9. Upper-right horizontal rib; 10. Lower-right horizontal rib; 11. Middle-lower horizontal rib; 12. Third welding hook edge; 13. Upper-left horizontal rib; 14. Left vertical rib; 15. Lower-left horizontal rib; 16. Fourth welding hook edge; 101. First cavity; 102. Second cavity; 103. Third cavity; 104. Threshold outer panel; 105. Threshold inner panel; 106. Mounting bolt. Detailed implementation manners

[0022] The roll-formed profile of the present invention is formed by welding a "day" - shaped roll-formed beam and a "C" - shaped roll-formed beam. The overall cross-sectional shape is "mesh" - shaped, including the first cavity 101, the second cavity 102, and the third cavity 103 arranged side by side. The first cavity 101 and the second cavity 102 are separated by the first intermediate reinforcing rib 1, the second cavity 102 and the third cavity 103 are separated by the second intermediate reinforcing rib 2. A projection welding nut 4 is welded on the right vertical rib 3 of the third cavity 103. The projection welding nut 4 is located inside the third cavity 103. A pre-punched hole is provided at the position where the projection welding nut 4 is welded on the right vertical rib 3. The size of the pre-punched hole is determined according to the relevant specifications of the selected projection welding nut according to industry standards for the opening size, and it is used for installation. Each corner of the three cavities is a rounded corner to reduce the stress concentration points of the profile and increase the anti-collision strength. The first cavity 101 is rectangular or trapezoidal, the second cavity 102 is rectangular or irregular, and the third cavity 103 is rectangular or trapezoidal. The irregular shape includes pentagons to polygons, the scheme of adding local concave or convex ribs on the horizontal and vertical ribs, and adding local special names on the horizontal and vertical ribs, etc.

[0023] The material thickness of the "C" - shaped and "day" - shaped roll-formed beams of the present invention can be the same or different, and the materials of the two roll-formed beams can be the same or different. There are differences in the selection of materials and material thicknesses, and the data can be adjusted according to actual needs to effectively control the peak contact force and the crushing sequence. Generally, the material strength of the first cavity is lower or the material thickness is smaller, so that the first peak of the contact force is lower during a collision, and the first cavity can be crushed first (the first cavity, the second cavity, and the third cavity are crushed in sequence), which is beneficial to improving the smoothness of the collapse and the energy absorption efficiency.

[0024] Compared with the integrally formed "eye" - shaped cross - section, the present invention uses the "C" - shaped and "day" - shaped roll - formed beams to be formed separately. The number of roll - formed bending round corners is less, the forming blind area is less, and the forming difficulty is significantly reduced.

[0025] As Figure 2 shown, the "day" - shaped roll - formed beam is a closed - type structure formed by cold - bending a steel plate multiple times, and includes a first intermediate reinforcing rib 1, a middle - upper horizontal rib 6, a second intermediate reinforcing rib 2, a first welding hook edge 7, a second welding hook edge 8, a right - upper horizontal rib 9, a right vertical rib 3, a right - lower horizontal rib 10, and a middle - lower horizontal rib 11. The first welding hook edge 7 and the second welding hook edge 8 are respectively welded to the right - lower horizontal rib 10 and the second intermediate reinforcing rib 2. The two welds are completed on the roll - punching line and are full - welds. The weld between the second welding hook edge 8 and the second intermediate reinforcing rib 2 uses laser welding, and the weld between the first welding hook edge 7 and the right - lower horizontal rib 10 uses roll - spot welding or laser welding. The second intermediate reinforcing rib 2, the middle - upper horizontal rib 6, the first intermediate reinforcing rib 1, and the middle - lower horizontal rib 11 enclose a second cavity 102 in sequence. The right - upper horizontal rib 9, the right vertical rib 3, the right - lower horizontal rib 10, and the second intermediate reinforcing rib 2 enclose a third cavity 103. The right - lower horizontal rib 10 and the middle - lower horizontal rib 11 are integral straight ribs. The "C" - shaped roll - formed beam is formed by cold - bending multiple times and includes a third welding hook edge 12, a left - upper horizontal rib 13, a left vertical rib 14, a left - lower horizontal rib 15, and a fourth welding hook edge 16. The third welding hook edge 12 and the fourth welding hook edge 16 are respectively welded to the top end and the bottom end of the first intermediate reinforcing rib 1. The two welds are full - welds or segmented welds, and the specific welding dimensions are matched according to the actual process and strength requirements.

[0026] The included angle c formed by the third welding hook edge 12 and the left - upper horizontal rib 13 is 30 - 135°, and the included angle f formed by the left - lower horizontal rib 15 and the fourth welding hook edge 16 is 30 - 135°. The included angle c and the included angle f can be the same or different. The included angle a formed by the middle - upper horizontal rib 6 and the second intermediate reinforcing rib 2 is 30 - 135°, and the included angle b formed by the middle - lower horizontal rib 11 and the second intermediate reinforcing rib 2 is 30 - 135°. The included angle a and the included angle b can be the same or different. The included angle d formed by the right - upper horizontal rib 9 and the right vertical rib 3 is 30 - 135°, and the included angle e formed by the right - lower horizontal rib 10 and the right vertical rib 3 is 30 - 135°. The included angle d and the included angle e can be the same or different. At the same time, the included angle c ≤ a ≤ d; the included angle f ≤ b ≤ e. By adjusting the above angles, the order of collision deformation can be effectively controlled, so that the cross - section satisfies that the first cavity deforms first, the second cavity deforms next, and the third cavity deforms last, which helps to control the crushing form.

[0027] The length of the first welding hook edge 7 ≥ 5 mm, the length of the second welding hook edge 8 ≥ 4 mm, and the lengths of the third welding hook edge 12 and the fourth welding hook edge 16 are both ≥ 4 mm.

[0028] See Figure 3 The sill is composed of three parts: an outer sill panel 104, a sill reinforcement member (the roll-formed profile with projection welding nuts in the present invention), and an inner sill panel 105. The outer sill panel and the inner sill panel are connected by traditional spot welding, and the sill reinforcement member also needs to be connected to the outer sill panel and the inner sill panel. Projection welding nuts are welded in the cavity of the roll-formed profile of the present invention, and the sill reinforcement member and the inner sill panel are fixedly connected by the projection welding nuts and mounting bolts.

[0029] The "C"-shaped roll-formed beam of the present invention can also be replaced by a "square" - shaped roll-formed beam.

[0030] The processing method of the high-strength roll-formed profile with projection welding nuts of the present invention includes the following steps: S1. Unroll, level, and pre-punch the sheet. S2. Feed the sheet with pre-punched holes into the welding workstation, and multiple welding robots complete the on-line projection welding of the projection welding nuts. S3. Feed the welded sheet into the cold roll-forming unit for multiple bending and forming. Both the second cavity and the third cavity are formed by relative inner winding bending. During processing, first complete the forming of the second cavity, complete the enclosure of the second cavity through the first welding, then complete the forming of the third cavity, and at the same time perform the second welding to complete the enclosure of the third cavity and connect the two cavities into one body, forming a "day" - shaped roll-formed profile with projection welding nuts. S3. Cut and下料 the roll-formed profile to a fixed length according to the required length. S4. After the "C"-shaped roll-formed beam is formed by multiple cold roll-forming processes, it is connected to the "day" - shaped roll-formed profile by welding to form an "eye" shape.

[0031] The step S3 is the roll-forming section of the "day" - shaped profile, which specifically includes the following steps: S31. High-precision forming of some structural features The sheet enters the first cold roll-forming unit. First, the welding process edges are formed on both sides simultaneously. At the same time, the right top corner of the second cavity is formed by multiple bending and springback control. Then, the outer top corners of the two cavities are formed on both sides simultaneously, and the bottom surface is bent in the opposite direction to avoid air bending, and the outer top corners on both sides are kept in a solid pressing state and formed to a certain angle. After that, the outer bottom corners of the two cavities are formed on both sides to a certain angle, and the bottom surface is flattened. A total of 3 forming passes are used to complete the high-precision forming of some structural features. S32. Forming of the second cavity First, control the forming of the left bottom corner through multiple bends and rebounds, and at the same time, control the forming of the left top corner through multiple bends and rebounds; secondly, slowly form the right bottom corner and top corner. By the forming speed difference between the two sides, leave a roller solid pressing space at the middle position to facilitate the closing of the second cavity; when the second cavity is closed, enter the first welding mechanism for primary welding to weld the first welding hook edge 7 and the lower right horizontal rib 10 to complete the closing of the second cavity. S33. Forming of the third cavity The profile enters the second cold bending forming unit. Form the right bottom corner through multiple bends, and at the same time, control the forming of the right top corner with rebound to complete the closing of the third cavity; when the third cavity is closed, enter the second welding mechanism for secondary welding to weld the second welding hook edge 8 and the second middle reinforcing rib 2 of the second cavity to connect the two cavities into one body to form a closed roll-pressed profile. S34. Precision control For the roll-pressed profile obtained in the step S33, first perform more precise cross-section precision control through a sizing unit, and then enter step S4 for welding with the "C" - shaped roll-pressed beam.

[0032] Specifically refer to Figure 4 that the forming process of the "day" - shaped cross-section requires a total of 9 steps and 32 times of bending forming.

[0033] In the first step, form the welding process hook edges on both sides simultaneously. At the same time, control the forming of the right top corner of the first cavity through multiple bends and rebounds, and a total of 7 times of forming are passed through (1 - 7 passes); In the second step, form the outer top corners of the cavity on both sides simultaneously, and adopt bottom surface reverse bending to avoid air bending, keep the outer top corners on both sides in a solid pressing state, and form the outer top corners to a certain angle, and a total of 4 times of forming are passed through (8 - 11 passes); In the third step, form the outer bottom corners of the cavity on both sides to a certain angle and flatten the bottom surface, and a total of 3 times of forming are passed through (12 - 14 passes); In the fourth step, complete the closing of the first cavity. First, control the forming of the left bottom corner through multiple bends and rebounds, and at the same time, control the forming of the left top corner through multiple bends and rebounds; secondly, slowly form the right bottom corner and top corner. By the forming speed difference between the two sides, leave a roller solid pressing space at the middle position to facilitate the closing of the first cavity, and a total of 10 times of forming are passed through (15 - 24 passes); In the fifth step, complete the closing of the second cavity. Form the right bottom corner through multiple bends, and at the same time, control the forming of the right top corner with rebound, and a total of 5 times of forming are passed through (25 - 29 passes); In the ninth step, perform more precise cross-section precision control through a sizing unit, and a total of 3 times of control are passed through (30 - 32 passes).

[0034] A molding production line based on the above processing method, such as Figure 5 As shown, it includes an uncoiler M6, a leveling, shearing and butt welding mechanism M7, a punching mechanism M8, a servo feeding mechanism M9, a missing punching detection mechanism M10, a projection welding nut welding workstation M11, a pit bridge M12, a first cold bending forming unit M13, a first welding mechanism M14, a second cold bending forming unit M15, a second welding mechanism M16, a cutting mechanism M17, and a receiving mechanism M18.

[0035] Among them, the uncoiler M6, the leveling, shearing, and welding mechanism M7, the punching mechanism M8, the servo feeding mechanism M9, the missing punching detection mechanism M10, the projection weld nut welding workstation M11, and the pit bridge M12 belong to the pre-rolling feeding section, used to prepare the sheet metal before roll forming. The first cold bending forming unit M13 and the first welding mechanism M14 belong to the first forming section, and the second cold bending forming unit M15 and the second welding mechanism M16 belong to the second forming section, used to cold bend the sheet metal in multiple passes to form a three-dimensional profile. The cutting mechanism M17 and the receiving mechanism M18 belong to the post-roll forming section. After processing, the profile is cut to a fixed length by the cutting mechanism to obtain a roll-formed profile with projection weld nuts.

[0036] Since the projection weld nut is welded before the sheet metal enters the cold bending unit, the roller die design needs to avoid the projection weld nut to prevent interference; for example Figure 6 As shown in the schematic diagram of the 10th pass mold design of the present invention, the avoidance method is to reduce the area of ​​the avoidance zone and increase the inner and outer surface area of ​​the pressed profile to improve the forming accuracy of the roll-formed profile. The roller mold is divided into upper rollers and lower rollers. The upper rollers include rollers 01, 02, 03, 04, 05 and 06. The lower rollers include rollers 07, 08, 09 and 10. Among them, roller 04 is a relief roller with projection welded nuts. The radial dimension of this roller is designed according to the minimum wall thickness. It mainly plays the role of fixed-length partitioning and avoidance, reducing material costs and processing costs.

[0037] The present invention will be further described below with reference to the embodiments.

[0038] For ease of description, in the following embodiments, in different roll forming profiles, the three cavities from left to right are respectively named the first cavity 101, the second cavity 102, and the third cavity 103. The corresponding ribs that form the second cavity are still named the upper middle horizontal rib, the first middle reinforcing rib, the lower middle horizontal rib, and the second middle reinforcing rib. The ribs that form the third cavity are named the second middle reinforcing rib, the upper right horizontal rib, the right vertical rib, and the lower right horizontal rib. Example 1

[0039] See Figure 2, the cross-section of the roll-formed profile is a "mu" - shaped profile formed by welding a "day" - shaped roll-formed beam and a "C" - shaped roll-formed beam. The third welding hook edge 12 and the fourth welding hook edge 16 on the "C" - shaped roll-formed beam are welded to the top and bottom of the first intermediate reinforcing rib 1 of the "day" - shaped roll-formed beam respectively, forming a first cavity 101, a second cavity 102 and a third cavity 103 arranged in sequence from left to right.

[0040] The "day" - shaped roll-formed beam is a closed structure formed by cold bending a steel plate multiple times, including a first intermediate reinforcing rib 1, a middle upper horizontal rib 6, a second intermediate reinforcing rib 2, a first welding hook edge 7, a second welding hook edge 8, a right upper horizontal rib 9, a right vertical rib 3, a right lower horizontal rib 10 and a middle lower horizontal rib 11; the first welding hook edge 7 and the second welding hook edge 8 are welded to the right side walls of the right lower horizontal rib 10 and the second intermediate reinforcing rib 2 respectively; the second intermediate reinforcing rib 2, the middle upper horizontal rib 6, the first intermediate reinforcing rib 1 and the middle lower horizontal rib 11 enclose the second cavity 102 in sequence; the right lower horizontal rib 10, the right vertical rib 3, the right upper horizontal rib 9 and the second intermediate reinforcing rib 2 enclose to form the third cavity 103. The middle lower horizontal rib and the right lower horizontal rib are an integral straight rib and are inclined downward from left to right, and the middle upper horizontal rib and the right upper horizontal rib are inclined upward. The projection welding nut is welded in the rightmost third cavity. The left upper horizontal rib of the "C" - shaped roll-formed beam is inclined upward, and the left lower horizontal rib is inclined downward, so that the first cavity 101, the second cavity 102 and the third cavity 103 are all trapezoidal. The trapezoidal first cavity formed by welding the "C" - shaped roll-formed beam and the "day" - shaped roll-formed beam has a height on the left side less than the height on the right welding side. The heights of the second cavity and the third cavity are also less on the left side than on the right side, making the overall height of the "mu" - shaped profile less on the left side than on the right side, ensuring that when side impact occurs, the first cavity deforms first and the crushing force gradually decreases from left to right.

[0041] The included angle c formed by the third welding hook edge 12 and the left upper horizontal rib 13 is 60°, the included angle f formed by the left lower horizontal rib 15 and the fourth welding hook edge 16 is 80°, the included angle a formed by the middle upper horizontal rib 6 and the second intermediate reinforcing rib 2 is 87°, and the included angle b formed by the middle lower horizontal rib 11 and the second intermediate reinforcing rib 2 is 85°; the included angle d formed by the right upper horizontal rib 9 and the right vertical rib 3 is 87°, and the included angle e formed by the right lower horizontal rib 10 and the right vertical rib 3 is 85°.

[0042] The length of the first welding hook edge 7 is 5mm, the length of the second welding hook edge 8 is 4mm, and the lengths of the third welding hook edge 12 and the fourth welding hook edge 16 are both 4mm. Embodiment 2

[0043] The cross-section of the roll-formed profile is a "mu" - shaped profile formed by welding a "day" - shaped roll-formed beam and a "C" - shaped roll-formed beam. See Figure 7, compared with Embodiment 1, the "day" - shaped rolling beam in this embodiment is equivalent to being mirror - set along the vertical direction with the "day" - shaped rolling beam in Embodiment 1. That is, the first welding hook edge is welded to the middle - lower horizontal rib, the second welding hook edge is welded to the left side wall of the second middle reinforcing rib. At the same time, the middle - lower horizontal rib and the lower - right horizontal rib are still an integral straight rib, and are arranged obliquely downward from left to right. The middle - upper horizontal rib and the upper - right horizontal rib are arranged obliquely upward, and the projection - welding nut is welded in the right - most third cavity. The setting of the "C" - shaped rolling beam is the same as that in Embodiment 1.

[0044] The included angle c formed by the third welding hook edge 12 and the upper - left horizontal rib 13 is 60°, the included angle f formed by the lower - left horizontal rib 15 and the fourth welding hook edge 16 is 80°, the included angle a formed by the middle - upper horizontal rib 6 and the second middle reinforcing rib 2 is 87°, and the included angle b formed by the middle - lower horizontal rib 11 and the second middle reinforcing rib 2 is 85°; the included angle d formed by the upper - right horizontal rib 9 and the right vertical rib 3 is 87°, and the included angle e formed by the lower - right horizontal rib 10 and the right vertical rib 3 is 85°. Embodiment 3

[0045] The cross - section of the rolled profile in this embodiment is still a "mu" - shaped profile formed by welding a "day" - shaped rolling beam and a "C" - shaped rolling beam. Refer to Figure 8 , compared with Embodiment 1, the "day" - shaped rolling beam in this embodiment is equivalent to being mirror - set along the horizontal direction with the "day" - shaped rolling beam in Embodiment 1. That is, the first welding hook edge is located above the "day" - shaped rolling beam and is welded to the upper - right horizontal rib. The middle - upper horizontal rib and the upper - right horizontal rib are an integral straight rib and are arranged obliquely upward from left; the second welding hook edge is located below and is welded to the right side wall of the second middle reinforcing rib. The projection - welding nut is welded in the right - most third cavity. The setting of the "C" - shaped rolling beam is the same as that in Embodiment 1.

[0046] The included angle c formed by the third welding hook edge 12 and the upper - left horizontal rib 13 is 60°, the included angle f formed by the lower - left horizontal rib 15 and the fourth welding hook edge 16 is 80°, the included angle a formed by the middle - upper horizontal rib 6 and the second middle reinforcing rib 2 is 87°, and the included angle b formed by the middle - lower horizontal rib 11 and the second middle reinforcing rib 2 is 85°; the included angle d formed by the upper - right horizontal rib 9 and the right vertical rib 3 is 87°, and the included angle e formed by the lower - right horizontal rib 10 and the right vertical rib 3 is 85°. Embodiment 4

[0047] The cross - section of the rolled profile in this embodiment is still a "mu" - shaped profile formed by welding a "day" - shaped rolling beam and a "C" - shaped rolling beam. Refer to Figure 9, compared with the cross-section of the roll-formed profile in Embodiment 2, the "day" - shaped roll-formed beam in this embodiment is equivalent to being mirror - set horizontally with the "day" - shaped roll-formed beam in Embodiment 2. That is, the first welding hook edge is located above the "day" - shaped roll-formed beam and is welded to the middle upper horizontal rib. The middle upper horizontal rib and the upper right horizontal rib are integral straight ribs, which are arranged obliquely from left to upward; the second welding hook edge is located below and is welded to the left side wall of the second middle reinforcing rib. The projection welding nut is welded in the rightmost third cavity. The setting of the "C" - shaped roll-formed beam is the same as that in Embodiment 1.

[0048] The included angle c formed by the third welding hook edge 12 and the upper left horizontal rib 13 is 60°. The included angle f formed by the lower left horizontal rib 15 and the fourth welding hook edge 16 is 80°. The included angle a formed by the middle upper horizontal rib 6 and the second middle reinforcing rib 2 is 87°. The included angle b formed by the middle lower horizontal rib 11 and the second middle reinforcing rib 2 is 85°. The included angle d formed by the upper right horizontal rib 9 and the right vertical rib 3 is 87°. The included angle e formed by the lower right horizontal rib 10 and the right vertical rib 3 is 85°.

[0049] Performance verification is carried out under the Y - direction static pressure condition (the Y - direction refers to the direction from the first cavity to the third cavity). Y - direction static pressure condition: Place the component on a rigid plane, and use a rigid column with a diameter of 254 mm to perform static pressure at a speed of 50 mm / min. The downward displacement is 70% of the Y - direction cross - section size of the product. With the same boundary, material, and material thickness, simulation analysis is carried out on the cross - section described in the present invention and the traditional "eye" - shaped cross - section. The results are shown in Table 1 below. The traditional cross - section refers to integrally cold - formed, see Figure 10 .

[0050] Table 1 Static pressure energy absorption of the embodiment and the conventional cross - section Example Static pressure energy absorption value / J Example 1 16752 Example 2 16530 Example 3 16574 Example 4 16651 Traditional cross section 12857 From the test results in the above table, it can be seen that the static pressure energy absorption value of the cross - section of the present invention is better than that of the traditional cross - section.

[0051] The above are only several embodiments of the present invention. All equivalent changes and modifications made according to the scope of the patent application of the present invention shall fall within the scope covered by the present invention, including closed cross - sections such as the closed - mouth cross - section "square", "B" - shaped, and integral closed - mouth "eye" - shaped cross - sections, but not limited to the above cross - sections.

[0052] The roll - formed profile of the present invention is not limited to products such as threshold reinforcements, battery case side beams, and anti - collision beams.

Claims

1. A high-strength roll-formed profile with projection weld nuts, characterized in that: The roll-formed profile is formed by welding a "day"-shaped roll-formed beam and a "C"-shaped roll-formed beam. The overall cross-section of the roll-formed profile is "eye"-shaped, including a first cavity (101), a second cavity (102), and a third cavity (103) arranged side by side. The first cavity (101) and the second cavity (102) are separated by a first intermediate reinforcing rib (1). The second cavity (102) and the third cavity (103) are separated by a second intermediate reinforcing rib (2). A projection welding nut (4) is welded on the right vertical rib (3) of the third cavity (103). The projection welding nut (4) is located inside the third cavity (103). A pre-punched hole is provided at the position where the projection welding nut (4) is welded on the right vertical rib (3).

2. The high-strength roll-formed profile with projection welded nut according to claim 1, characterized in that: The "day"-shaped roll-formed beam is a closed structure formed by multiple cold bending of a steel plate, including a first intermediate reinforcing rib (1), a middle upper horizontal rib (6), a second intermediate reinforcing rib (2), a first welding hook edge (7), a second welding hook edge (8), a right upper horizontal rib (9), a right vertical rib (3), a right lower horizontal rib (10), and a middle lower horizontal rib (11); the first welding hook edge (7) and the second welding hook edge (8) are respectively welded to the right lower horizontal rib (10) and the second intermediate reinforcing rib (2); the second intermediate reinforcing rib (2), the middle upper horizontal rib (6), the first intermediate reinforcing rib (1), and the middle lower horizontal rib (11) sequentially enclose the second cavity (102); the right lower horizontal rib (10), the right vertical rib (3), the right upper horizontal rib (9), and the second intermediate reinforcing rib (2) enclose to form the third cavity (103).

3. The high-strength roll-formed profile with projection welded nut according to claim 2, characterized in that: The "C"-shaped roll-formed beam is formed by multiple cold bending, including a third welding hook edge (12), a left upper horizontal rib (13), a left vertical rib (14), a left lower horizontal rib (15), and a fourth welding hook edge (16). The third welding hook edge (12) and the fourth welding hook edge (16) are respectively welded to the top end and the bottom end of the first intermediate reinforcing rib (1).

4. The high-strength roll-formed profile with projection weld nut according to claim 3, characterized in that: The length of the first welding hook edge (7) ≥ 5 mm, the length of the second welding hook edge (8) ≥ 4 mm, and the lengths of the third welding hook edge (12) and the fourth welding hook edge (16) are both ≥ 4 mm.

5. The high-strength roll-formed profile with projection welded nut according to claim 4, characterized in that: The first cavity (101) is rectangular or trapezoidal, the second cavity (102) is rectangular or irregular, and the third cavity (103) is rectangular or trapezoidal.

6. The high-strength roll-formed profile with projection welded nut according to claim 5, characterized in that: The included angle c formed by the third welding hook edge (12) and the upper left horizontal rib (13) is 30° to 135°, and the included angle f formed by the lower left horizontal rib (15) and the fourth welding hook edge (16) is 30° to 135°. The included angle c and the included angle f are the same or different; the included angle a formed by the middle upper horizontal rib (6) and the second middle reinforcing rib (2) is 30° to 135°, and the included angle b formed by the middle lower horizontal rib (11) and the second middle reinforcing rib (2) is 30° to 135°. The included angle a and the included angle b are the same or different; the included angle d formed by the upper right horizontal rib (9) and the right vertical rib (3) is 30° to 135°, and the included angle e formed by the lower right horizontal rib (10) and the right vertical rib (3) is 30° to 135°. The included angle d and the included angle e are the same or different; the included angle c ≤ a ≤ d; the included angle f ≤ b ≤ e.

7. A method for processing a high-strength roll-formed profile with projection weld nuts as described in any one of claims 1-6, characterized in that: The processing method includes the following steps: S1. Uncoil, level, and pre-punch the sheet metal. S2. Feed the sheet metal with pre-punched holes into the welding workstation, and multiple welding robots complete the welding of the in-line projection welding nuts. S3. Feed the welded sheet metal into the cold bending forming unit for multiple bending formations. Both the second cavity and the third cavity are formed by relative inner winding bending; during processing, first complete the formation of the second cavity, complete the enclosure of the second cavity through the first welding, then complete the formation of the third cavity, and at the same time perform the second welding to complete the enclosure of the third cavity and connect the two cavities into one body to form a "day”-shaped rolled profile with projection welding nuts. S3. Cut and blank the rolled profile to a fixed length according to the required length. S4. Connect the "C”-shaped rolled beam formed by multiple roll bending with the "day”-shaped rolled profile through welding to form a "mu”-shaped rolled profile.

8. The processing method of high-strength roll-formed profile with projection weld nut according to claim 7, characterized in that: The step S3 is the rolling forming section of the "day”-shaped profile, which specifically includes the following steps: S31. High-precision forming of some structural features The sheet metal enters the first cold bending forming unit. First, simultaneously form the welding process hook edges on both sides, and at the same time, control the forming of the right top angle of the second cavity through multiple bends and springbacks; then, simultaneously form the outer top angles of the two cavities on both sides, and use bottom surface reverse bending to avoid empty bending, and keep the outer top angles on both sides in a solid pressing state, and form the outer top angles to a certain angle. After that, simultaneously form the outer bottom angles of the two cavities on both sides to a certain angle, and flatten the bottom surface. A total of 3 passes are used for forming, and thus some structural features are formed with high precision. S32. Formation of the second cavity First, control the forming of the left bottom angle through multiple bends and springbacks, and at the same time control the forming of the left top angle through multiple bends and springbacks; secondly, slowly form the right bottom angle and the top angle, and leave a real pressing space for the roller in the middle position through the forming speed difference on both sides to facilitate the enclosure of the second cavity; when the second cavity is enclosed, enter the first welding mechanism for one-time welding, and weld the first welding hook edge (7) and the lower right horizontal rib (10) to complete the enclosure of the second cavity. S33. Formation of the third cavity The profile enters the second cold bending forming unit, and forms the bottom right corner by bending multiple times, while the springback control is used to form the top right corner, thus completing the closure of the third cavity; when the third cavity is closed, it enters the second welding mechanism for secondary welding, welding the second welding hook (8) to the second intermediate reinforcing rib (2) of the second cavity, connecting the two cavities into one, and forming a closed roll-formed profile; S34, Precision Control The roll-formed profile obtained in step S33 is first subjected to more precise cross-sectional accuracy control by a sizing unit before proceeding to step S4.

9. The processing method of the high-strength roll-formed profile with projection weld nut according to claim 8, characterized in that: The primary and secondary welding are either arc welding or fusion welding; the arc welding is selected from tungsten inert gas welding, gas metal arc welding, carbon dioxide gas shielded arc welding or plasma arc welding, and the fusion welding is selected from electron beam welding or laser welding.

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