Roll forming machine and forming method for forming snap-fit ​​structures of sheet metal parts

Abstract

This application provides a roll forming machine and a forming method for forming a snap-fit ​​structure of sheet metal parts. The roll forming machine includes a frame, and the frame is provided with multiple sets of roller groups and multiple sets of guide roller groups along the feeding direction of the sheet metal parts. The guide roller groups are arranged interlaced between adjacent sets of roller groups along the feeding direction. The guide roller groups are divided into a left guide roller group and a right guide roller group. The roller groups include a first forming die group, a second forming die group and a third forming die group. The left guide roller group includes a first folding die group and a folding die group. The right guide roller group includes a folding die group and a second folding die group. The forming method is to form a locking edge structure by bending the sheet metal parts on the left edge using the first folding die group, forming a left overlap portion by bending the sheet metal parts on the left side using the folding die group, forming a right overlap portion by bending the sheet metal parts on the right side using the right guide roller group, and forming a locking edge structure by bending the sheet metal parts on the right side using the second folding die group.

Description

Technical Field

[0001] This application relates to the technical field of sheet metal cold bending forming machines, and more particularly to a roll forming machine and forming method for forming sheet metal fastening structures. Background Technology

[0002] Roofing profiles are often made of sheet metal (such as steel plates) and are formed by roll forming. They are suitable for roofs of industrial and civil buildings, warehouses, special buildings, and large-span steel structure houses. They are lightweight, high-strength, earthquake-resistant, fireproof, and rainproof, and are now widely used.

[0003] In actual production applications, the roofing profiles are bent on both sides to form a left overlap and a right overlap, respectively. The left overlap is placed on the right overlap of the adjacent roofing profile, splicing the adjacent roofing profile fasteners together. Existing roll forming equipment is mostly used for forming simple cross-sectional shapes. For sheet metal parts with complex overlaps, especially structures that require multiple bends, interlocking, or snap-fitting, there is a lack of dedicated roll forming equipment, resulting in insufficient forming accuracy and unstable fastening structure, which affects subsequent assembly and performance. Summary of the Invention

[0004] In view of the above practical problems and the shortcomings of the existing technology, the main technical problem to be solved by the present invention is to provide a roll forming machine and forming method for forming the snap-fit ​​structure of sheet metal parts, which can realize high-precision and continuous snap-fit ​​structure forming, improve production efficiency, reduce manufacturing costs, and meet the diversified needs of modern manufacturing industry for sheet metal structural parts.

[0005] To solve the above-mentioned technical problems, this application provides a roll forming machine for forming the fastening structure of sheet metal parts, adopting the following technical solution:

[0006] A roll forming machine for forming the fastening structure of sheet metal parts includes a frame. The frame is provided with multiple sets of roller groups and multiple sets of guide roller groups along the feeding direction of the sheet metal parts. The guide roller groups are arranged in one or more interlaced arrangements between adjacent sets of roller groups along the feeding direction. The guide roller groups are divided into a left guide roller group and a right guide roller group.

[0007] The frame is rotatably provided with multiple upper and lower rotating shafts arranged opposite each other along the feeding direction. Each group of rollers includes several upper and lower pressure rollers sleeved and fixed to the upper and lower rotating shafts. The several upper and lower pressure rollers in each group form a first forming die group, a second forming die group, and a third forming die group along the axial direction of the rotating shaft, respectively. The upper and lower pressure rollers corresponding to the first forming die group and the second forming die group are used to gradually form several first protrusions on the main body of the sheet metal part in the first forming stage.

[0008] The first forming die assembly includes a first upper pressure roller and a first lower pressure roller, and the third forming die assembly includes a third upper pressure roller and a third lower pressure roller; in the second forming stage of the sheet metal part, the corresponding first upper pressure roller is provided with a second outer protrusion protruding outward along the radial direction, and the first lower pressure roller is provided with a second inner groove corresponding to the second outer protrusion; the pressing surfaces of the third upper pressure roller and the third lower pressure roller are configured with a reverse Z-shaped pressing surface structure along the axial direction.

[0009] The second outer protrusion and the second inner groove cooperate to form a downward rolling pressing cavity, which is used to gradually form a first folded edge structure on the left side of the sheet metal part. The first folded edge structure is composed of a downwardly recessed structure with a V-shape on the outside and a folded edge on the inside for connecting the main body of the sheet metal part; the reverse Z-shaped pressing surface structure is used to gradually form a second folded edge structure on the right side of the sheet metal part.

[0010] In the third forming stage of the sheet metal part, the corresponding third upper pressure roller is provided with a third outer protrusion in the radial direction, and the third lower pressure roller is provided with a third inner groove corresponding to the third outer protrusion; the third outer protrusion and the third inner groove cooperate to form a pressing cavity for downward rolling, which is used to gradually form the folded part and the pre-forming of the locking structure on the outside of the second folded edge structure of the sheet metal part.

[0011] In the fourth forming stage of the sheet metal part, the third lower pressure roller is provided with a fourth outer protrusion in the radial direction, and the third upper pressure roller is provided with a fourth inner groove corresponding to the fourth outer protrusion; the fourth outer protrusion and the fourth inner groove cooperate to form an upward rolling pressing cavity, which is used for the connection part of the sheet metal part connected to the sheet metal part body inside the second folding structure to gradually form the second protrusion.

[0012] In the second forming stage of the sheet metal part, the corresponding left-side support roller group is the first folding edge module. The first folding edge module is used to snap the left side of the V-shaped downward concave structure inward to form a locking edge structure. In the third forming stage of the sheet metal part, the corresponding left-side support roller group is the folding module. The folding module is used to fold the folded edge used to connect the sheet metal part body inward. The V-shaped downward concave structure is folded inward and snapped under the sheet metal part body to form a left overlapping part.

[0013] In the second forming stage of the sheet metal part, the corresponding right-side support roller group is a bending and pressing module, which further bends the second folded edge structure to form a right overlapping part; in the third forming stage of the sheet metal part, the corresponding right-side support roller is a second folding edge module, which further snaps the pre-formed locking edge structure on the outside of the second folding edge structure inward to form the second folded edge structure.

[0014] In a preferred embodiment, the second forming punch includes a second upper pressure roller and a second lower pressure roller. The first lower pressure roller and the second lower pressure roller include a first outward protrusion protruding radially outward. The first upper pressure roller and the second upper pressure roller are provided with a first inner groove corresponding to the position of the first outward protrusion. The first protrusion and the first inner groove cooperate to form an upward rolling pressing cavity, which is used to gradually form the first protrusion on the main body of the sheet metal part. The first protrusion is an upward protrusion structure in the shape of an inverted V.

[0015] The height of the first outer protrusion in the multiple sets of rollers gradually increases along the feeding direction, and the height of the first inner groove in the multiple sets of rollers gradually increases along the feeding direction.

[0016] In a preferred embodiment, the height of the second outer protrusion and the depth of the second inner groove gradually increase along the feeding direction; the second outer protrusion is located to the left of the first inner groove provided by the first upper pressure roller, and the second inner groove is located to the left of the first outer protrusion provided by the first lower pressure roller.

[0017] In a preferred embodiment, the first folding module includes two folding shafts arranged in parallel and at a certain angle to the horizontal plane. The upper folding shaft is fitted with a first upper roller, and the lower folding shaft is fitted with a first lower roller.

[0018] The pressing surface of the first lower roller includes a radially concave first folded edge groove, and the pressing surface of the first upper roller is a conical pressing surface. The left pressing surface of the conical pressing surface is in a close-fitting rotational fit with the left inner wall of the first folded edge groove, and the right pressing surface of the conical pressing surface is in a clearance fit with the right inner wall of the first folded edge groove.

[0019] The gap is used for the passage of the first folded edge structure formed on the left side of the sheet metal part, and when the sheet metal part passes through, the right pressing surface of the tapered pressing surface will snap the left side of the V-shaped downward concave structure inward to form a locking edge structure.

[0020] In a preferred embodiment, the folding module includes a first left pressure roller and a first right pressure roller arranged left and right. The first left pressure roller and the first right pressure roller are respectively sleeved and fixed on the corresponding folding shaft. The pressing surface of the first left pressure roller includes a folding groove that is concave in the radial direction. The first right pressure roller includes a cam for cooperating with the folding groove. There is a transition surface that is concave in the radial direction between the cam and the body of the first right pressure roller.

[0021] When the sheet metal part passes through the folding module, the folded edge used to connect the main body of the sheet metal part fits into the folding groove, and the cam presses on the corner of the folded edge used to connect the main body of the sheet metal part. The folded edge used to connect the main body of the sheet metal part is gradually folded inward through the folding groove and the cam.

[0022] The angle between the folding axis and the vertical plane of the multiple sets of folding modules gradually increases along the feeding direction, and the depth of the folding groove gradually increases along the feeding direction.

[0023] In a preferred embodiment, the folding module includes a second upper roller and a second lower roller arranged at a certain angle to each other. The second upper roller and the second lower roller are both sleeved and fixed on the corresponding folding shaft. The pressing surfaces of the second upper roller and the second lower roller each include radially inward folding grooves. The two folding grooves are connected to each other to form a reverse Z-shaped folding shape.

[0024] The depth of the two bending grooves gradually increases along the feeding direction, and the included angle between the extended lines of the two side walls of the bending groove gradually decreases;

[0025] The two included angles corresponding to the Z-shaped pressing surface structure of the third upper pressure roller and the third lower pressure roller gradually approach 90° along the feeding direction; the two included angles corresponding to the Z-shaped folding shape of the reverse Z-shaped pressing shape are less than 90° and gradually approach 10° along the feeding direction.

[0026] In a preferred embodiment, the third outer protrusion and the third inner groove are disposed at a position near the right side of the third forming die assembly, and the height of the third outer protrusion and the depth of the third inner groove gradually increase along the feeding direction;

[0027] The fourth outer protrusion and the fourth inner groove are located near the left side of the third forming die assembly, and the height of the fourth outer protrusion and the depth of the fourth inner groove gradually increase along the feeding direction.

[0028] In a preferred embodiment, the second folding module comprises a second left pressure roller and a second right pressure roller arranged horizontally, the second left pressure roller and the second right pressure roller being respectively sleeved and fixed on the corresponding folding shaft; the pressing surface of the second right pressure roller includes a radially concave second folding groove.

[0029] The depth of the second folded groove gradually increases along the feeding direction; the pressing surface of the second left pressure roller is a conical pressing surface.

[0030] In a preferred embodiment, in the third and fourth forming stages of the sheet metal part, the corresponding first forming die group is provided with a first clearance structure; in the second forming stage of the sheet metal part, the corresponding third forming die group is provided with a second clearance structure; and in the fourth forming stage of the sheet metal part, the corresponding third forming die group is provided with a third clearance structure.

[0031] To solve the above-mentioned technical problems, this application provides a roll forming method for forming the snap-fit ​​structure of sheet metal parts, adopting the following technical solution:

[0032] The forming method is based on the roller forming machine, which uses multiple sets of rollers and multiple sets of guide rollers arranged sequentially from the feed end to the discharge end of the roller forming machine to form in stages: the first forming stage, the second forming stage, the third forming stage and the fourth forming stage.

[0033] The molding method includes the following steps:

[0034] Step 1: Feeding preparation. The sheet metal parts to be formed are fed into the frame of the roll forming machine. The roll forming machine is started, which drives the upper pressure roller, lower pressure roller and multiple sets of rollers to run synchronously, and enters the first forming stage.

[0035] Step 2, First Molding Stage:

[0036] Through the cooperation of the upper and lower pressure rollers corresponding to the first punch group and the second punch, several first protrusions are gradually formed on the main body of the sheet metal part, and sheet metal allowance is left on the outer side of the first protrusions on the leftmost and rightmost sides.

[0037] Step 3, Second Molding Stage:

[0038] 3.1 Pre-forming of left and right side structures: Through the pressing cavity formed by the second outer protrusion and the second inner groove in the first forming die group in the second forming stage, the sheet metal allowance on the left side of the roll forming sheet metal part forms the first folded edge structure; at the same time, through the reverse Z-shaped pressing surface structure of the third forming die group in the second forming stage, the sheet metal allowance on the right side of the roll forming sheet metal part forms the second folded edge structure.

[0039] 3.2 Preliminary forming of left side locking edge and right side overlap: In the second forming stage, the left side of the V-shaped downward concave structure of the first folding edge structure is snapped inward by the first folding edge module on the left side to initially form the locking edge; at the same time, the second folding edge structure is bent by the right side bending and pressing module in the second forming stage to form the right overlap part, thus completing this stage;

[0040] Step 4, Third Molding Stage:

[0041] 4.1 Right side edge preforming and folding part forming: Through the pressing cavity formed by the third outer protrusion and the third inner groove in the third forming die group in the third forming stage, the folding part and edge preforming are formed by rolling on the outside of the second folding edge;

[0042] 4.2 Right side edge locking and shaping: The pre-formed edge is locked inward and shaped using the second folding module on the right side;

[0043] In the forming stages 4.1 and 4.2, the left side overlap forming is carried out simultaneously. Through the left side folding module, the folding edge of the first folded edge connected to the sheet metal body is folded inward, so that the V-shaped downward concave structure forms the left overlap part, thus completing this stage.

[0044] Step 5, Fourth Molding Stage:

[0045] The second protrusion is formed by rolling the connecting part of the sheet metal body on the inner side of the second folded edge through the pressing cavity in the third forming die group of the fourth forming stage where the fourth outer protrusion and the fourth inner groove cooperate; this stage is completed.

[0046] Step 6: Finished product forming, the formed sheet metal part is output from the discharge end.

[0047] In summary, this application has the following beneficial effects:

[0048] 1. This invention provides a roll forming machine for forming sheet metal fastening structures. It can roll form sheet metal parts into a single piece to produce roofing profiles that can be quickly installed and spliced. It can continuously and rapidly roll form on a large scale, with high production efficiency, low cost, and good forming accuracy, which can effectively meet the production needs of enterprises.

[0049] 2. Reasonable structural design and high forming precision: The roll forming machine uses alternating groups of rollers and guide rollers to precisely align the first, second, and third forming punch groups with the left guide roller group (first folding die group, folding die group) and the right guide roller group (folding and pressing die group, second folding die group) at each forming stage. Combined with the pressing cavities formed by the protrusions and grooves, it achieves precise forming of each part of the sheet metal fastening structure, effectively controlling the dimensional deviations of each fold, overlap, and locking structure, improving product forming precision, and meeting subsequent assembly requirements. The setting of various clearance structures avoids interference problems during the roll forming process, further ensuring forming quality. Attached Figure Description

[0050] Figure 1 This is a schematic diagram of the overall structure of the sheet metal part to be formed in this embodiment;

[0051] Figure 2 This is a schematic diagram of the feed end of the roll forming machine frame in this embodiment;

[0052] Figure 3 This is a schematic diagram of the discharge end of the roll forming machine frame in this embodiment;

[0053] Figure 4 This is a schematic diagram of the roll forming process of the first forming stage, the second forming stage, the third forming stage and the fourth forming stage of the sheet metal part to be formed in this embodiment.

[0054] Figure 5 This is a roll forming diagram of the roller group in the first forming stage of this embodiment;

[0055] Figure 6 This is a roll forming diagram of one of the roller groups in the second forming stage of this embodiment;

[0056] Figure 7 This is a roll forming diagram of another stage of the roller assembly in the second forming stage of this embodiment;

[0057] Figure 8 This is a roll forming diagram of the bending and pressing module in the second forming stage of this embodiment;

[0058] Figure 9 This is a schematic diagram of the second clearance structure of the roller group in the second forming stage of this embodiment;

[0059] Figure 10 This is a roll forming diagram of the first folding module and the folding and pressing module in this embodiment.

[0060] Figure 11 This is a roll forming diagram of the folding module and the pressing module in this embodiment;

[0061] Figure 12 This is a roll forming diagram of one of the roller groups in the third forming stage of this embodiment;

[0062] Figure 13 This is a roll forming diagram of another stage of the roller assembly in the third forming stage of this embodiment;

[0063] Figure 14 This is a roll forming diagram of the folding module in the third forming stage of this embodiment;

[0064] Figure 15 This is a roll forming diagram of the second folding module in the third forming stage of this embodiment;

[0065] Figure 16 This is a roll forming diagram of the roller group in the fourth forming stage of this embodiment.

[0066] Explanation of reference numerals in the attached drawings: 1. Roll forming machine; 11. First protrusion; 12. Left overlap portion; 121. First folded edge structure; 13. Right overlap portion; 131. Reverse Z-shaped bending portion; 132. Second folded edge structure; 14. Locking edge structure; 15. U-shaped structure; 16. Folding portion; 17. Second protrusion; 2. Sheet metal part; 21. Frame; 22. Roller group; 221. Upper rotating shaft; 222. Lower rotating shaft; 223. Upper pressure roller; 2231. First inner groove; 224. 2241. Lower pressure roller; 225. First outer protrusion; 225. First forming die assembly; 2251. First upper pressure roller; 2252. First lower pressure roller; 2253. Second outer protrusion; 2254. Second inner groove; 2255. First clearance structure; 226. Second forming die assembly; 227. Third forming die assembly; 2271. Third upper pressure roller; 2272. Third lower pressure roller; 2273. Reverse Z-shaped pressing surface structure; 2274. Second clearance structure; 2275. Third outer protrusion; 227 6. Third inner groove; 2277. Fourth outer protrusion; 2278. Fourth inner groove; 2279. Third clearance structure; 23. Left side wheel assembly; 231. First folding module; 2311. First upper roller; 2312. First lower roller; 2313. First folding groove; 232. Folding module; 2321. First left pressure roller; 2322. First right pressure roller; 2323. Folding shaft; 2324. Folding groove; 2325. Cam; 2326. Transition surface; 24. Right side near the roller assembly; 241, folding and pressing module; 2411, second upper roller; 2412, second lower roller; 2413, folding and pressing shaft; 2414, folding and pressing groove; 242, second folding edge module; 2421, second left pressure roller; 2422, second right pressure roller; 2423, second folding edge groove; 100, first forming stage; 200, second forming stage; 200-1, pre-pressing part; 200-2, shaping part; 300, third forming stage; 400, fourth forming stage. Detailed Implementation

[0067] 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. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0068] In the description of this invention, it should be noted that the terms "upper," "lower," "inner," "outer," "top / bottom," 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 element 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. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0069] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installed", "equipped", "sleeved / connected", "connected", etc., should be interpreted broadly. For example, "connection" can be a wall-mounted connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. For those skilled in the art, the specific meaning of the above terms in this invention can be understood according to the specific circumstances.

[0070] The following is in conjunction with the appendix Figure 1 This application will be described in further detail.

[0071] refer to Figure 1 In this embodiment, the sheet metal part 2 to be formed has a middle part and two side fastening structures. The middle part has four first protrusions 11, and the two side fastening structures are divided into a left overlapping part 12 and a right overlapping part 13. Both the left overlapping part 12 and the right overlapping part 13 are provided with a locking edge structure 14. The locking edge structure 14 is formed by bending the edges of both sides of the sheet metal part 2 inward to form a U-shaped folded edge structure. The left overlapping part 12 is located below the leftmost first protrusion 11 of the middle part. The left overlapping part 12 is a V-shaped structure with an included angle ≥120°. The connection between the left overlapping part 12 and the leftmost first protrusion 11 of the middle part is a U-shaped structure 15 that folds downward and inward. The right overlapping part 13 is connected to the right locking edge structure 14 through a folded part 16. The connection between the right overlapping part 13 and the rightmost first protrusion 11 of the middle part is provided with a second protrusion 17. The right overlapping part 13 is a reverse Z-shaped bent part 131. In this embodiment, the sheet metal parts can be roll-formed using YX25-250 / 290 series sheet metal parts.

[0072] The sheet metal part 2 formed in this embodiment mainly focuses on forming its complex interlocking structure. During the forming process, the sheet metal part 2 is first pre-rolled using a rolling mill to form the four first protrusions 11 in the middle section, ensuring that the height and spacing of the first protrusions 11 are uniform, thus laying the foundation for the forming of the interlocking structure on both sides. Subsequently, the forming operation of the interlocking structure on both sides is carried out step by step:

[0073] On the left side, the left edge of the sheet metal part 2 is bent inward using a special bending die to form a U-shaped locking structure 14. At the same time, the left overlapping part 12 is bent and shaped, and its V-shaped angle is controlled to be no less than 120° to ensure the overlap fit. Then, the connection between the left overlapping part 12 and the leftmost first protrusion 11 is folded to form a downward and inward U-shaped structure 15. This U-shaped structure 15 can enhance the structural strength of the connection part and avoid stress concentration that could lead to breakage when subjected to force.

[0074] The forming of the right-side fastening structure needs to take into account the coordinated forming of the locking edge structure 14, the folded portion 16, the reverse Z-shaped bend portion 131, and the second protrusion 17. First, the right overlapping portion 13 is bent on the right side of the sheet metal part 2 to form the reverse Z-shaped bend portion 131. This structural design can adapt to the overlapping requirements in subsequent assembly, improving the overall assembly accuracy and stability of the sheet metal part. Then, through the combination of rolling and bending, the folded portion 16 connecting the locking edge structure 14 and the right overlapping portion 13 is formed. After edge finishing, the U-shaped locking edge structure 14 consistent with the left side is formed. Next, at the connection between the right overlapping portion 13 and the rightmost first protrusion 11, the second protrusion 17 is formed by local rolling. The second protrusion 17 can further enhance the tightness of the connection between the two and prevent loosening after assembly.

[0075] refer to Figure 2-16 In order to form the above-mentioned sheet metal part 2 structure, this embodiment provides a method as follows: Figure 2 , Figure 3 The roll forming machine 1 shown is used to form the snap-fit ​​structure of sheet metal part 2. The roll forming machine 1 is driven by an 11KW closed-loop motor and is a column-type roll forming machine. The roll forming machine 1 includes a frame 21. The frame 21 is provided with multiple sets of roller groups 22 and multiple sets of guide roller groups along the feeding direction of sheet metal part 2. The guide roller groups are arranged in one or more interlaced positions between adjacent sets of roller groups 22 along the feeding direction. Roller group 22 is used to bend and form four first protrusions 11 in the middle part of sheet metal part 2, as well as a first folded edge structure 121 connected to the leftmost first protrusion 11 and a second folded edge structure 132 connected to the rightmost first protrusion 11. The roller group is divided into a left roller group 23 and a right roller group 24. The left roller group 23 is used to further shape the first folded edge structure 121 formed by roller group 22 into a left overlapping part 12. The right roller group 24 is used to further shape the second folded edge structure 132 formed by roller group 22 into a right overlapping part 13.

[0076] The frame 21 is rotatably equipped with multiple upper rotating shafts 221 and lower rotating shafts 222 arranged vertically opposite to each other along the feeding direction of the sheet metal part 2. (See reference) Figure 5Each roller group 22 includes, from left to right, a first forming punch group 225, a second forming punch group 226, and a third forming punch group 227 along the axial direction of the rotating shaft. Each punch group includes an upper pressure roller 223 and a lower pressure roller 224 respectively sleeved on the upper rotating shaft 221 and the lower rotating shaft 222. The pressing surface of the lower pressure roller 224 includes a first outer protrusion 2241 protruding radially outward. The upper pressure roller 223 is provided with a first inner groove 2231 corresponding to the position of the first outer protrusion 2241. The height of the first outer protrusion 2241 of the lower pressure roller 224 in the multiple roller groups 22 gradually increases along the feeding direction, and the depth of the first inner groove 2231 of the corresponding upper pressure roller 223 gradually increases along the feeding direction. The first outer protrusion 2241 and the first inner groove 2231 are rolled together to form an upward rolling pressing cavity, which is used to gradually form the first protrusion 11 on the sheet metal part 2. The first protrusion 11 is an upward protruding structure in an inverted V shape. The first protrusion 11 constitutes the main forming structure of the sheet metal part 2.

[0077] like Figure 4 The roll forming machine 1, with multiple sets of roller groups 22 and multiple sets of guide roller groups, performs a first forming stage 100, a second forming stage 200, a third forming stage 300, and a fourth forming stage 400 on the sheet metal part 2. The first forming stage 100 is the roll forming stage of the first protrusion 11, in which the sheet metal part 2 is roll-formed into the shape of the first protrusion 11 by the roller group 22; the second forming stage 200 is the roll forming stage of the first folded edge structure 121 and the locking edge structure 14 on the left side of the sheet metal part 2 and the right overlapping part 13; the third forming stage 300 is the roll forming stage of the left overlapping part 12 and the right locking edge structure 14 on the right side of the sheet metal part 2; and the fourth forming stage 400 is the roll forming stage of the second protrusion 17 on the right side of the sheet metal part 2.

[0078] The first external protrusion 2241 and the first internal groove 2231 are disposed on the upper pressure roller 223 and lower pressure roller 224 of the second forming die group 226 and the first forming die group 225, respectively. The second forming die group 226 includes three pairs of second upper pressure rollers and second lower pressure rollers. Each pair of second upper pressure rollers and second lower pressure rollers is respectively provided with the first external protrusion 2241 and the first internal groove 2231. In the first forming stage 100, the height of the first external protrusion 2241 corresponding to the second forming die group 226 is [missing information]. The depth of the first inner groove 2231 gradually increases along the feeding direction. In the first forming stage 100, the main body of the sheet metal part is gradually formed into three first protrusions 11 by the second forming die group 226. In the first forming stage, the first upper pressure roller 2251 and the first lower pressure roller 2252 corresponding to the first forming die group 225 are set with the same specifications and dimensions as the first outer protrusion 2241 and the first inner groove 2231, which are used to form the first protrusion 11 located on the far left.

[0079] The first forming die group 225 and the second forming die group 226 cooperate to gradually form four first protrusions 11 in the main body of the sheet metal part in the first forming stage 100. In the subsequent second forming stage 200, third forming stage 300 and fourth forming stage 400, the height of the first outer protrusion 2241 and the depth of the first inner groove 2231 remain unchanged, laying the benchmark for the subsequent roll forming of the sheet metal part on both sides.

[0080] The four first protrusions 11 are located in the middle left of the sheet metal part. The outer side of the leftmost first protrusion 11 is reserved for sheet metal part allowance for forming the left overlapping part 12, and the outer side of the rightmost first protrusion 11 is reserved for sheet metal part allowance for forming the right overlapping part 13.

[0081] The specific structure of the roll forming of the left overlapping portion 12 is as follows:

[0082] The first forming die assembly 225 is used to bend and form the leftmost first protrusion 11 and the first folded edge structure 121. As the sheet metal part 2 is gradually rolled, after the first forming stage 100 rolling is completed, in the roller assembly 22 corresponding to the second forming stage 200 rolling, the first upper pressure roller 2251 of the first forming die assembly 225 has a second outer protrusion 2253 protruding radially outward, and its first lower pressure roller 2252 has a second inner groove 2254 corresponding to the second outer protrusion 2253 (see reference). Figure 6 , Figure 7 The height of the second outer protrusion 2253 and the depth of the second inner groove 2254 gradually increase along the feeding direction. The second outer protrusion 2253 is located to the left of the first inner groove 2231 provided on the first upper pressure roller 2251, and the second inner groove 2254 is located to the left of the first outer protrusion 2241 provided on the first lower pressure roller 2252. The second outer protrusion 2253 and the second inner groove 2254 cooperate to form a downward rolling pressing cavity, which is used to gradually form the first folded edge structure 121 on the left side of the sheet metal part. The first folded edge structure 121 is composed of a downwardly recessed structure with a V-shape on the outside and a folded edge connected to the first protrusion 11 on the inside (see reference). Figure 7 The V-shaped downward recessed structure on the outside is the preform of the left overlapping part 12 and the locking structure 14.

[0083] In the second forming stage 200, the last two rolling processes are performed by the left-side roller assembly 23. The left-side roller assembly 23 for these two processes uses the first folding module 231. The first folding module 231 folds the leftmost edge of the V-shaped downward-recessed structure of the first folding structure 121 downwards at an angle to form the locking edge structure 14. (Reference) Figure 10Specifically, the first folding module 231 includes two parallel folding shafts arranged at a certain angle to the horizontal plane. A first upper roller 2311 is fixedly fitted onto the upper folding shaft, and a first lower roller 2312 is fitted onto the lower folding shaft. The pressing surface of the first lower roller 2312 includes a radially concave first folding groove 2313, the shape of which matches the shape of the first folding structure 121. The pressing surface of the first upper roller 2311 is a conical pressing surface. The left pressing surface of the tapered pressing surface is in a close-fitting rotational fit with the left inner wall of the first folding groove 2313, and the right pressing surface of the tapered pressing surface is in a clearance fit with the right inner wall of the first folding groove 2313. This clearance allows the first folding structure 121 formed on the left side of the sheet metal part 2 to pass through. When the sheet metal part 2 passes through, the right pressing surface of the tapered pressing surface is used to press the leftmost edge of the V-shaped downward concave structure of the first folding structure 121 obliquely downward, and the leftmost edge is folded inward to form a locking edge structure 14, such as... Figure 10 After the sheet metal part 2 is rolled by the first folding module 231, the locking structure 14 is finally formed on the leftmost side of the V-shaped downward concave structure of the first folding structure 121.

[0084] After the second forming stage 200 is completed, the third forming stage 300 uses at least one set of left side roller group 23 and roller group 22 to alternately distribute the rollers. The left side roller group 23 of the third forming stage 300 uses a folding module 232. The folding module 232 is used to fold the folded edge of the first folded edge structure 121 connected to the sheet metal body inward and upward to form a U-shaped structure, so that the first folded edge structure 121 is folded inward and pressed to the lower part of the leftmost first protrusion 11 in the middle part, forming the left overlapping part 12.

[0085] refer to Figure 11The folding module 232 includes a first left pressure roller 2321 and a first right pressure roller 2322 arranged to the left and right respectively. The first left pressure roller 2321 and the first right pressure roller 2322 are respectively sleeved and fixed on the corresponding folding shaft 2323. The pressing surface of the first left pressure roller 2321 includes a radially inwardly concave folding groove 2324. The first right pressure roller 2322 includes a cam 2325 for cooperating with the folding groove 2324. There is a radially inwardly transition surface 2326 between the cam 2325 and the main body of the first right pressure roller 2322. The first folding edge structure 121 is used to connect the folding edge of the sheet metal part body to the inner lower side wall of the folding groove 2324 for edge-fitting. The left side of the leftmost first protrusion 11 is fitted to the inner upper side wall of the folding groove 2324 for edge-fitting. The cam 2325 forms a tangential rotational engagement with the bottom of the folding groove 2324. Cam 2325 presses on the corner of the folded edge used to connect the sheet metal body. Through the pressing of folding groove 2324 and cam 2325, the first folded edge structure 121 used to connect the sheet metal body is gradually folded inward and upward. Finally, the V-shaped downward concave structure is folded inward and buckled under the sheet metal body to form the left overlapping part 12.

[0086] refer to Figure 14 The angle between the folding shaft 2323 of the multiple folding modules 232 and the vertical plane gradually increases along the feeding direction, and the depth of the folding groove 2324 gradually increases along the feeding direction. After being rolled by the multiple folding modules 232, the left overlapping part 12 is finally formed. In the third forming stage 300 and the fourth forming stage 400, the first forming punch group 225 of the roller group 22 is provided with a first clearance structure 2255. The position of the first clearance structure 2255 corresponds to that of the first folding structure 121. (Refer to...) Figure 12 , 13 The second inner groove 2254 of the first lower pressure roller 224 of the first forming punch assembly 225 cooperates with the first inner groove 2231 together with the first outer protrusion 2241. At this time, the second inner groove 2254 serves as the first clearance structure 2255, which is used to clearance the first folded edge structure 121 formed by the left side roller, so as to avoid unnecessary interference during the rolling process.

[0087] The specific structure of the roll forming of the right overlapping portion 13 is as follows:

[0088] The third forming punch assembly 227 is used to cooperate with the right-side roller assembly 24 to bend and form the right overlapping part 13. As the sheet metal part 2 is gradually rolled, after the first forming stage 100 rolling is completed, in the roller assembly 22 corresponding to the second forming stage 200 rolling, the pressing surfaces of the third upper pressing roller 2271 and the third lower pressing roller 2272 of the third forming punch assembly 227 form a reverse Z-shaped pressing surface structure 2273 from left to right along the axial direction. The pressing surface structure of the third upper pressing roller 2271 and the third lower pressing roller 2272 is referenced. Figure 6The two included angles corresponding to the Z-shape of the third upper pressure roller 2271 and the third lower pressure roller 2272 gradually approach 90° along the feeding direction, for reference. Figure 7 The third punch group 227 is used to gradually roll the sheet metal part 2 on the right side to form a second folded edge structure 132 with a 90° included angle.

[0089] In the second forming stage 200, the rolling of the right overlapping portion 13 is further divided into a pre-pressing section 200-1 and a shaping section 200-2. The pre-pressing section 200-1 is pressed by the third forming punch group 227 until the sheet metal part 2 on the right side is formed to form a second folded edge structure 132 with a 90° included angle. The shaping section 200-2 is rolled by the right side roller group 24. In the shaping section 200-2, the right side roller group 24 is arranged alternately with the roller group 22 in one, two, or three groups. The right side roller of the shaping section 200-2 uses a folding and pressing module 241. The folding and pressing module 241 is used to press the second folded edge structure 132 with a 90° included angle inward to form a reverse Z-shaped bending portion 131 with an included angle of ≤10°. The reverse Z-shaped bending portion 131 forms the right overlapping portion 13. (See reference) Figure 8 .

[0090] refer to Figure 8 The folding module 241 includes two upper rollers 2411 and lower rollers 2412 with their central axes set at a certain angle. The upper rollers 2411 and lower rollers 2412 are both sleeved and fixed on the corresponding folding shafts 2413. The pressing surfaces of the upper rollers 2411 and lower rollers 2412 each include radially inward folding grooves 2414. The two folding grooves 2414 are connected to each other to form a reverse Z-shaped folding shape. The folding grooves 2414 of the upper rollers 2411 are used for folding the upper angle area of ​​the reverse Z-shape, and the folding grooves 2414 of the lower rollers 2412 are used for folding the lower angle area of ​​the reverse Z-shape to form the right overlapping part 13.

[0091] The depth of the two bending grooves 2414 gradually increases along the feeding direction, and the included angle between the extended lines of the two side walls of the bending grooves 2414 gradually decreases. (Refer to...) Figure 10 , Figure 11 Finally, the right side of sheet metal part 2 is formed by continuous rolling of the bending module 241, as shown in the figure. Figure 11 The reverse Z-shaped bending portion 131 is shown. A gap is provided between the two left pressure surfaces of the reverse Z-shaped bending portion 131 and the third upper pressure roller 2271 and the third lower pressure roller 2272 of the third forming die group 22 on the forming section 200-2, as shown in the reference section. Figure 9 This gap forms a second clearance structure 2274, which is used to make way for the reverse Z-shaped bending portion 131, avoiding unnecessary interference during the rolling process.

[0092] After the second forming stage 200 roll pressing is completed, in the third forming die group 227 of the roller group 22 corresponding to the third forming stage 300 roll pressing, in the two right pressure surfaces of the third upper pressure roller 2271 and the third lower pressure roller 2272 in the reverse Z-shape, the upper right pressure surface is provided with a third outer protrusion 2275 radially outward, and the lower right pressure surface is provided with a third inner groove 2276 corresponding to the third outer protrusion 2275. (Reference) Figure 12 , Figure 13 The height of the third outer protrusion 2275 and the depth of the third inner groove 2276 gradually increase along the feeding direction, which are used for the rolling of the right folded part 16 and the pre-rolling of the locking edge structure 14. The pre-rolling of the locking edge structure 14 is to fold the right edge of the sheet metal part upward to form a right folded edge that tends to 90°.

[0093] In the last two rolling stages of the third forming stage 300, the right-side roller assembly 24 is used for rolling. These two right-side rollers employ a second folding module 242. The second folding module 242 is used to further fold and inwardly press the pre-rolled edge of the right-side sheet metal part 2 to form the locking edge structure 14, thus forming the locking edge structure 14. (Reference) Figure 15 The second folding module 242 consists of a second left pressure roller 2421 and a second right pressure roller 2422 arranged on the left and right sides, respectively. The second left pressure roller 2421 and the second right pressure roller 2422 are respectively sleeved and fixed on the corresponding folding shaft. The pressing surface of the second right pressure roller 2422 includes a radially concave second folding groove 2423. The outer wall of the right folding edge and the second folding groove 2423 are in edge fit. The depth of the second folding groove 2423 gradually increases along the feeding direction. The pressing surface of the second left pressure roller 2421 is a conical pressing surface. Its conical pressing surface is in edge fit with the inner wall of the right folding edge. The second folding groove 2423 is used to press the right folding edge inward to form the shape of the locking structure 14.

[0094] refer to Figure 16 After the third forming stage 300 roll pressing is completed, in the roller group 22 corresponding to the fourth forming stage 400 roll pressing, the third lower roller 2272 of the third forming punch group 227 has a fourth outer protrusion 2277 radially outward on the pressing surface near the left side. The third upper roller 2271 has a fourth inner groove 2278 corresponding to the fourth outer protrusion 2277. The fourth outer protrusion 2277 and the fourth inner groove 2278 cooperate to form an upward rolling pressing cavity, which is used for the sheet metal part 2 to gradually roll press the second protrusion 17 of the connecting part of the sheet metal part 2 connected to the main body of the sheet metal part 2 inside the right overlapping part 13. At the same time, a gap is provided between the two pressing surfaces on the right side of the third lower roller 2272 and the third upper roller 2271. This gap forms a third clearance structure 2279, which is used to clearance the right side locking structure 14 to avoid unnecessary interference during the rolling process.

[0095] The aforementioned roll forming machine 1 can roll form sheet metal parts 2 into a single piece to produce roof profiles that can be quickly installed and spliced. It can continuously and rapidly roll form on a large scale, with high production efficiency, low cost, and good forming accuracy, which can effectively meet the production needs of enterprises.

[0096] Based on the roll forming machine for forming the snap-fit ​​structure of sheet metal parts provided above, this embodiment provides a roll forming method for forming the snap-fit ​​structure of sheet metal part 2. The roll forming machine 1 uses multiple sets of roller groups 22 and multiple sets of guide roller groups arranged sequentially from the feed end to the discharge end to progressively form the sheet metal part in stages: a first forming stage 100, a second forming stage 200, a third forming stage 300, and a fourth forming stage 400. The forming method includes the following steps:

[0097] Step 1: Feeding preparation. The sheet metal part 2 to be formed is fed into the frame 21 of the roll forming machine 1. The upper rotating shaft 221 and the lower rotating shaft 222 on the frame 21 are started, which drives the upper pressure roller 223, the lower pressure roller 224 and the multiple sets of roller groups 22 to rotate synchronously, ensuring that the roller group 22 and the roller group alternately cooperate along the feeding direction, and enter the first forming stage 100.

[0098] Step 2: First forming stage 100, forming the four first protrusions 11 in the middle part of the sheet metal part 2;

[0099] By the coordinated action of multiple sets of roller groups 22 arranged along the feeding direction, the first upper pressure roller 223 and the first lower pressure roller 224 of the first punch group 225 and the second upper pressure roller 223 and the second lower pressure roller 224 of the second punch group 226 are used to gradually roll and press four first protrusions 11 on the main body of the sheet metal part 2.

[0100] Step 3: Second molding stage 200, entering the pre-molding and preliminary shaping stage of segmented progressive molding, specifically including:

[0101] 3.1 Left side structure preforming: Through the first forming punch group 225 of the roller group 22 corresponding to the second forming stage 200, the left side of the sheet metal part 2 is gradually rolled by the pressing cavity formed by the second outer protrusion 2253 of the first upper pressing roller 223 and the second inner groove 2254 of the first lower pressing roller 224, so that the left side of the sheet metal part 2 gradually forms the first folded edge structure 121. The first folded edge structure 121 is composed of a downwardly recessed structure with a V-shape on the outside and a folded edge on the inside for connecting the main body of the sheet metal part 2.

[0102] 3.2 Right side structure preforming: Through the roller group 22 and the third forming punch group 227 corresponding to the second forming stage 200, the reverse Z-shaped pressing surface structure 2273 of the third upper pressing roller 2271 and the third lower pressing roller 2272 is used to gradually roll the right side of the sheet metal part 2, so that the right side of the sheet metal part 2 gradually forms the second folded edge structure 132.

[0103] 3.3 Preliminary forming of the left side locking edge: By using the left side support roller group 23 (first folding edge module 231) corresponding to the second forming stage 200, the left side of the V-shaped downward concave structure in the first folding edge structure 121 is snapped inward to initially form the locking edge structure 14.

[0104] 3.4 Preliminary forming of the right side overlap: The second folded edge structure 132 is further bent by the right side roller group 24 (folding and pressing module 241) corresponding to the second forming stage 200, and the right overlap part 13 is initially formed, thus completing the second forming stage 200.

[0105] Step 4: Third forming stage 300, entering the forming and shaping stage of the interlocking structure, specifically including:

[0106] 4.1 Right side edge preforming and folding part 16 forming: Through the roller group 22 and the third forming die group 227 corresponding to the third forming stage 300, the pressing cavity formed by the third outer protrusion 2275 of the third upper pressing roller 2271 and the third inner groove 2276 of the third lower pressing roller 2272 is used to gradually roll and press on the outside of the second folding structure 132 to form the folding part 16 and the edge preforming of the edge structure 14.

[0107] 4.2 Left side overlap forming: By using the left side roller group 23 (folding module 232) corresponding to the third forming stage 300, the folding edge in the first folding edge structure 121 used to connect the main body of the sheet metal part 2 is folded inward, so that the V-shaped downward concave structure is folded inward and buckled under the main body of the sheet metal part 2, and finally the left overlap part 12 is formed.

[0108] 4.3 Right side edge shaping: By using the right side roller group 24 (second folding module 242) corresponding to the third forming stage 300, the pre-formed edge locking structure 14 on the outside of the second folding structure 132 is further fastened inward to complete the shaping of the edge locking structure 14 and complete the third forming stage 300.

[0109] Step 5: Fourth forming stage 400, structural reinforcement and precise shaping are performed. Through the roller group 22 and the third forming die group 227 corresponding to the fourth forming stage 400, the fourth outer protrusion 2277 of the third lower pressure roller 2272 and the fourth inner groove 2278 of the third upper pressure roller 2271 are used to form an upward rolling pressing cavity, which gradually rolls the connecting part of the inner side of the second folded structure 132 to the main body of the sheet metal part 2, so that the second protrusion 17 is gradually formed in this part, thus completing the fourth forming stage 400.

[0110] Step 6: Finished product forming. After four stages of progressive forming, the formed sheet metal part 2 is output through the discharge end of the roll forming machine 1, completing the roll forming of the entire sheet metal part 2 fastening structure.

[0111] The above description is merely a preferred embodiment of the present invention, but the design concept of the present invention is not limited thereto. Any non-substantial modifications made to the present invention by those skilled in the art within the scope of the technology disclosed in the present invention using this concept shall be deemed as an infringement of the protection scope of the present invention.

Claims

1. A roll forming machine for forming the fastening structure of sheet metal parts, characterized in that: The machine includes a frame, which is provided with multiple sets of roller groups and multiple sets of guide roller groups along the feeding direction of the sheet metal parts. The guide roller groups are arranged in one or more interlaced arrangements between adjacent sets of roller groups along the feeding direction. The guide roller groups are divided into a left guide roller group and a right guide roller group. The frame is rotatably provided with multiple upper and lower rotating shafts arranged opposite each other along the feeding direction. Each group of rollers includes several upper and lower pressure rollers sleeved and fixed to the upper and lower rotating shafts. The several upper and lower pressure rollers in each group form a first forming die group, a second forming die group, and a third forming die group along the axial direction of the rotating shaft, respectively. The upper and lower pressure rollers corresponding to the first forming die group and the second forming die group are used to gradually form several first protrusions on the main body of the sheet metal part in the first forming stage. The first forming die assembly includes a first upper pressure roller and a first lower pressure roller, and the third forming die assembly includes a third upper pressure roller and a third lower pressure roller; in the second forming stage of the sheet metal part, the corresponding first upper pressure roller is provided with a second outer protrusion protruding outward along the radial direction, and the first lower pressure roller is provided with a second inner groove corresponding to the second outer protrusion; the pressing surfaces of the third upper pressure roller and the third lower pressure roller are configured with a reverse Z-shaped pressing surface structure along the axial direction. The second outer protrusion and the second inner groove cooperate to form a downward rolling pressing cavity, which is used to gradually form a first folded edge structure on the left side of the sheet metal part. The first folded edge structure is composed of a downwardly recessed structure with a V-shape on the outside and a folded edge on the inside for connecting the main body of the sheet metal part; the reverse Z-shaped pressing surface structure is used to gradually form a second folded edge structure on the right side of the sheet metal part. In the third forming stage of the sheet metal part, the corresponding third upper pressure roller is provided with a third outer protrusion in the radial direction, and the third lower pressure roller is provided with a third inner groove corresponding to the third outer protrusion; the third outer protrusion and the third inner groove cooperate to form a pressing cavity for downward rolling, which is used to gradually form the folded part and the pre-forming of the locking structure on the outside of the second folded edge structure of the sheet metal part. In the fourth forming stage of the sheet metal part, the third lower pressure roller is provided with a fourth outer protrusion in the radial direction, and the third upper pressure roller is provided with a fourth inner groove corresponding to the fourth outer protrusion; the fourth outer protrusion and the fourth inner groove cooperate to form an upward rolling pressing cavity, which is used for the connection part of the sheet metal part connected to the sheet metal part body inside the second folding structure to gradually form the second protrusion. In the second forming stage of the sheet metal part, the corresponding left-side support roller group is the first folding edge module. The first folding edge module is used to snap the left side of the V-shaped downward concave structure inward to form a locking edge structure. In the third forming stage of the sheet metal part, the corresponding left-side support roller group is the folding module. The folding module is used to fold the folded edge used to connect the sheet metal part body inward. The V-shaped downward concave structure is folded inward and snapped under the sheet metal part body to form a left overlapping part. In the second forming stage of the sheet metal part, the corresponding right-side support roller group is a bending and pressing module, which further bends the second folded edge structure to form a right overlapping part; in the third forming stage of the sheet metal part, the corresponding right-side support roller is a second folding edge module, which further snaps the pre-formed locking edge structure on the outside of the second folding edge structure inward to form the second folded edge structure.

2. The roll forming machine for forming the fastening structure of sheet metal parts according to claim 1, characterized in that: The second forming punch includes a second upper pressure roller and a second lower pressure roller. The first lower pressure roller and the second lower pressure roller include a first outward protrusion protruding radially outward. The first upper pressure roller and the second upper pressure roller are provided with a first inner groove corresponding to the position of the first outward protrusion. The first protrusion and the first inner groove cooperate to form an upward rolling pressing cavity, which is used to gradually form the first protrusion on the main body of the sheet metal part. The first protrusion is an upward protrusion structure in the shape of an inverted V. The height of the first outer protrusion in the multiple sets of rollers gradually increases along the feeding direction, and the height of the first inner groove in the multiple sets of rollers gradually increases along the feeding direction.

3. The roll forming machine for forming the fastening structure of sheet metal parts according to claim 2, characterized in that: The height of the second outer protrusion and the depth of the second inner groove gradually increase along the feeding direction; the second outer protrusion is located to the left of the first inner groove provided by the first upper pressure roller, and the second inner groove is located to the left of the first outer protrusion provided by the first lower pressure roller.

4. The roll forming machine for forming the fastening structure of sheet metal parts according to claim 1, characterized in that: The first folding module includes two folding shafts arranged in parallel and at a certain angle to the horizontal plane. The upper folding shaft is fitted with a first upper roller, and the lower folding shaft is fitted with a first lower roller. The pressing surface of the first lower roller includes a radially concave first folded edge groove, and the pressing surface of the first upper roller is a conical pressing surface. The left pressing surface of the conical pressing surface is in a close-fitting rotational fit with the left inner wall of the first folded edge groove, and the right pressing surface of the conical pressing surface is in a clearance fit with the right inner wall of the first folded edge groove. The gap is used for the passage of the first folded edge structure formed on the left side of the sheet metal part, and when the sheet metal part passes through, the right pressing surface of the tapered pressing surface will snap the left side of the V-shaped downward concave structure inward to form a locking edge structure.

5. The roll forming machine for forming the fastening structure of sheet metal parts according to claim 1, characterized in that: The folding module includes a first left pressure roller and a first right pressure roller arranged in a left-right configuration. The first left pressure roller and the first right pressure roller are respectively sleeved and fixed on the corresponding folding shaft. The pressing surface of the first left pressure roller includes a folding groove that is concave in the radial direction. The first right pressure roller includes a cam for cooperating with the folding groove. There is a transition surface that is concave in the radial direction between the cam and the body of the first right pressure roller. When the sheet metal part passes through the folding module, the folded edge used to connect the main body of the sheet metal part fits into the folding groove, and the cam presses on the corner of the folded edge used to connect the main body of the sheet metal part. The folded edge used to connect the main body of the sheet metal part is gradually folded inward through the folding groove and the cam. The angle between the folding axis and the vertical plane of the multiple sets of folding modules gradually increases along the feeding direction, and the depth of the folding groove gradually increases along the feeding direction.

6. The roll forming machine for forming the snap-fit ​​structure of sheet metal parts according to claim 1, characterized in that: The folding module includes a second upper roller and a second lower roller with their central axes set at a certain angle. The second upper roller and the second lower roller are both sleeved and fixed on the corresponding folding shaft. The pressing surfaces of the second upper roller and the second lower roller each include radially inward folding grooves. The two folding grooves are connected to each other to form a reverse Z-shaped folding shape. The depth of the two bending grooves gradually increases along the feeding direction, and the included angle between the extended lines of the two side walls of the bending groove gradually decreases; The two included angles corresponding to the Z-shaped pressing surface structure of the third upper pressure roller and the third lower pressure roller gradually approach 90° along the feeding direction; the two included angles corresponding to the Z-shaped folding shape of the reverse Z-shaped pressing shape are less than 90° and gradually approach 10° along the feeding direction.

7. The roll forming machine for forming the fastening structure of sheet metal parts according to claim 1, characterized in that: The third outer protrusion and the third inner groove are located near the right side of the third forming die assembly, and the height of the third outer protrusion and the depth of the third inner groove gradually increase along the feeding direction. The fourth outer protrusion and the fourth inner groove are located near the left side of the third forming die assembly, and the height of the fourth outer protrusion and the depth of the fourth inner groove gradually increase along the feeding direction.

8. The roll forming machine for forming the fastening structure of sheet metal parts according to claim 1, characterized in that: The second folding module comprises a second left pressure roller and a second right pressure roller arranged horizontally, with the second left pressure roller and the second right pressure roller respectively sleeved and fixed on the corresponding folding shaft; the pressing surface of the second right pressure roller includes a radially concave second folding groove. The depth of the second folded groove gradually increases along the feeding direction; the pressing surface of the second left pressure roller is a conical pressing surface.

9. The roll forming machine for forming the fastening structure of sheet metal parts according to claim 1, characterized in that: In the third and fourth forming stages of the sheet metal part, the corresponding first forming die group is provided with a first clearance structure; in the second forming stage of the sheet metal part, the corresponding third forming die group is provided with a second clearance structure; and in the fourth forming stage of the sheet metal part, the corresponding third forming die group is provided with a third clearance structure.

10. A roll forming method for forming a fastening structure of sheet metal parts, the forming method being based on a roll forming machine according to any one of claims 1-9, wherein multiple sets of roller groups and multiple sets of guide roller groups are sequentially arranged along the feed end to the discharge end of the roll forming machine to progressively form in stages according to a first forming stage, a second forming stage, a third forming stage and a fourth forming stage; The molding method includes the following steps: Step 1: Feeding preparation. The sheet metal parts to be formed are fed into the frame of the roll forming machine. The roll forming machine is started, which drives the upper pressure roller, lower pressure roller and multiple sets of rollers to run synchronously, and enters the first forming stage. Step 2, First Molding Stage: Through the cooperation of the upper and lower pressure rollers corresponding to the first punch group and the second punch, several first protrusions are gradually formed on the main body of the sheet metal part, and sheet metal allowance is left on the outer side of the first protrusions on the leftmost and rightmost sides. Step 3, Second Molding Stage: 3.1 Pre-forming of left and right side structures: Through the pressing cavity formed by the second outer protrusion and the second inner groove in the first forming die group in the second forming stage, the sheet metal allowance on the left side of the roll forming sheet metal part forms the first folded edge structure; at the same time, through the reverse Z-shaped pressing surface structure of the third forming die group in the second forming stage, the sheet metal allowance on the right side of the roll forming sheet metal part forms the second folded edge structure. 3.2 Preliminary forming of left side locking edge and right side overlap: In the second forming stage, the left side of the V-shaped downward concave structure of the first folding edge structure is snapped inward by the first folding edge module on the left side to initially form the locking edge; at the same time, the second folding edge structure is bent by the right side bending and pressing module in the second forming stage to form the right overlap part, thus completing this stage; Step 4, Third Molding Stage: 4.1 Right side edge preforming and folding part forming: Through the pressing cavity formed by the third outer protrusion and the third inner groove in the third forming die group in the third forming stage, the folding part and edge preforming are formed by rolling on the outside of the second folding edge; 4.2 Right side edge locking and shaping: The pre-formed edge is locked inward and shaped using the second folding module on the right side; In the forming stages 4.1 and 4.2, the left side overlap forming is carried out simultaneously. Through the left side folding module, the folding edge of the first folded edge connected to the sheet metal body is folded inward, so that the V-shaped downward concave structure forms the left overlap part, thus completing this stage. Step 5, Fourth Molding Stage: The second protrusion is formed by rolling the connecting part of the sheet metal body on the inner side of the second folded edge through the pressing cavity in the third forming die group of the fourth forming stage where the fourth outer protrusion and the fourth inner groove cooperate; this stage is completed. Step 6: Finished product forming, the formed sheet metal part is output from the discharge end.

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