Apparatus for manufacturing flanged tubular rivets, manufacturing method, method for riveting sheet metal

Abstract

The application belongs to the technical field of mechanical connection, and particularly discloses a preparation device of a flange pipe rivet, which comprises an upper die, a lower die and a stud; the bottom end structure of the upper die is annular protrusion; the upper die and the lower die are both hollow cylinders; the stud is movably connected in the lower die; the flange pipe rivet comprises a pipe rivet and a flange connected to the outer circumferential surface of the pipe rivet; during processing, the pipe rivet is partially located in the upper die and partially located in the lower die, and the flange is placed between the annular protrusion structure and the lower die. The application further discloses a manufacturing method of the flange pipe rivet, which comprises the following steps: through annular extrusion on the flange, the flange and the pipe rivet are plastically deformed in a certain degree in the radial direction; after unloading, the flange and the pipe rivet are tightly combined due to elastic recovery, there is no obvious stress concentration point, and if force imbalance occurs during operation, slight slippage can occur during connection, so that the risk of direct fracture of the flange is reduced.

Description

Technical Field

[0001] This invention belongs to the field of mechanical connection technology, and specifically discloses a preparation device, manufacturing method, and riveting plate method for a flanged tubular rivet. Background Technology

[0002] Unequal thickness plate connectors are widely used in the automotive, aerospace, pharmaceutical, and food industries. Traditional connection processes for unequal thickness plates mainly include bolting, gluing, and riveting. However, all traditional connection methods have certain drawbacks. For example, bolting requires pre-drilled holes, and the screws and bolts increase the weight of the connector and pose a risk of detachment under vibration; gluing requires curing, has a long curing period, and results in lower joint strength; conventional riveting methods such as self-piercing riveting and stud riveting can leave pits or protrusions on the upper and lower surfaces of the connector, affecting the aesthetics of the surface of the component.

[0003] Double-sided self-piercing riveting of sheet metal is a concealed, high-strength connection method with a high degree of surface flatness and no need for pre-drilled holes. However, for connecting plates of unequal thickness, the insertion depth of conventional tubular rivets is difficult to control, easily leading to the problem of penetration through the thinner plate side (e.g., Figure 5 (as shown in a); for connections between dissimilar materials, penetration is easily achieved on the low-strength side (e.g., as shown in a). Figure 5 (As shown in b). To address the problems of joint tilting and inaccurate positioning in ordinary tubular riveting connections, CN 101804440 A discloses a flanged tubular riveting method for connecting smooth and flat plate surfaces. The flange can be circular, square, hexagonal, triangular, etc., greatly enriching the flange selection. Although this document discloses the structure of the flanged tubular rivet, its structure is a one-piece molding structure. Such complex-shaped flanges are primarily machined, increasing processing costs and time. Once the flange's position in the tubular rivet is machined, it is difficult to change, resulting in poor process flexibility and making it unsuitable for double-sided self-piercing riveting connections between plates with significant differences in thickness and mechanical properties. Therefore, there is an urgent need for a low-cost, efficient, and highly flexible method for manufacturing and using flanged tubular rivets. Summary of the Invention

[0004] The purpose of this invention is to provide a preparation apparatus, manufacturing method, and riveting method for flanged tubular rivets, which solves the problem that there is no low-cost, high-efficiency, and highly flexible manufacturing apparatus for flanged tubular rivets in the prior art.

[0005] This invention is achieved through the following technical solution:

[0006] A manufacturing apparatus for flanged tubular rivets includes an upper die, a lower die, and studs; the bottom end structure of the upper die is an annular protrusion.

[0007] Both the upper and lower molds are hollow cylinders; the stud is movably connected to the lower mold.

[0008] The flanged tubular rivet includes a tubular rivet and a flange connected to the outer circular surface of the tubular rivet;

[0009] During processing, part of the tubular rivet is located inside the upper mold, and the other part is located inside the lower mold. A flange is placed between the annular protrusion and the lower mold.

[0010] Furthermore, the flange outer diameter is D, and the thickness is t2, where D = (1.5~2)d, 0.5mm ≤ t2 ≤ 1.0mm, and d is the outer diameter of the tubular rivet.

[0011] The dimension between the lower end face of the flange and the bottom end face of the tubular rivet is h2, the height of the tubular rivet is h1, and h2 = (0.2~0.7)h1;

[0012] h1=(0.8~1.2)(t 上板材 +t 下板材 ), t 上板材 t represents the thickness of the upper plate to be connected. 下板材 The thickness of the lower plate to be connected.

[0013] Furthermore, the flange thickness is t2, and the height of the annular protrusion is h0 = (1~3)t2.

[0014] Furthermore, the thickness of the annular protrusion is l, where 0.5mm ≤ l ≤ 3mm.

[0015] Furthermore, the wall thickness of the tubular rivet is t1, where 0.5mm ≤ t1 ≤ 2mm.

[0016] Furthermore, the tubular rivet has pre-made chamfers at both ends, with the chamfer at the end of the tubular rivet being θ, where 30°≤θ≤60°.

[0017] Furthermore, the tubular rivets and flanges are made of 304 or 316L stainless steel.

[0018] The present invention also discloses a method for manufacturing a flanged tubular rivet, based on the aforementioned manufacturing apparatus, comprising the following steps:

[0019] S1. Determine the flange position based on the thickness and material of the upper and lower plates to be connected:

[0020] When the thicknesses of the upper and lower plates are different, the flange should be positioned closer to the thinner side of the plate.

[0021] When the upper and lower plates have the same thickness but different materials, the flange should be positioned closer to the side of the plate with lower hardness.

[0022] S2. Adjust the stud to the preset position, place the tubular rivet in the countersunk hole formed by the lower die and the stud, fit the flange on the outer wall of the tubular rivet, and fit the upper die on the outside of the upper section of the tubular rivet.

[0023] S3. The upper die moves downward and squeezes the flange, causing radial plastic deformation of the flange and acting on the tubular rivet. After the upper die moves to the preset position, it stops and moves upward to the initial position. Due to the elastic recovery of the tubular rivet, a tight connection is formed between the flange and the tubular rivet, resulting in a tubular rivet with a flange.

[0024] The method for preparing flanged tubular rivet-jointed plates by the aforementioned manufacturing method includes the following steps:

[0025] Place the lower plate on the lower flat mold, place the flanged tubular rivet at the position to be connected on the lower plate, and place the upper plate at the part to be riveted on the upper part of the tubular rivet; when the upper plate and the lower plate have different thicknesses, the flange position is closer to the thinner side of the plate; when the upper plate and the lower plate have the same thickness but different materials, the flange position is closer to the weaker side of the plate.

[0026] The lower die moves upward to press the lower plate. The upper end of the tubular rivet pierces the upper plate and the lower end pierces the lower plate, and they bend and deform inside the plate to form a mechanical lock until the surfaces of the upper and lower plates come into contact with each other, and the plate connection process is completed.

[0027] Compared with the prior art, the present invention has the following beneficial technical effects:

[0028] This invention discloses a manufacturing apparatus for flanged tubular rivets, comprising an upper mold and a lower mold. During processing, part of the tubular rivet is located in the upper mold, and the other part is located in the lower mold. A flange is placed between the annular protrusion structure and the lower mold, and the vertical position of the flange is adjusted by a stud. A tight connection between the flange and the tubular rivet is achieved by extruding the flange, resulting in a flanged tubular rivet. This reduces machining time and difficulty, and the material utilization rate exceeds 95%, significantly higher than that of machining. The apparatus is simple in structure, low in processing cost, and easy to operate. Flanges at any position can be obtained by adjusting the stud height. For small batches of multi-specification connecting plates, only the flange height needs to be determined according to the connection position to manufacture flanged tubular rivets of the corresponding height, thus satisfying the connection between plates of the same or different materials and different thicknesses. The process flexibility far exceeds that of machined flanged tubular rivets.

[0029] This invention also discloses a method for manufacturing flanged tubular rivets. Compared to flanged tubular rivets obtained through machining methods such as turning, this invention uses circumferential extrusion of the flange to induce a certain degree of radial plastic deformation in both the flange and the tubular rivet. After unloading, elastic recovery results in a tight bond between the flange and the tubular rivet, eliminating obvious stress concentration points. If an imbalance of forces occurs during operation, slight slippage during connection can reduce the risk of direct flange breakage. In contrast, turning disrupts the fiber continuity of the original structure, creating stress concentration points at the flange root. If an imbalance of forces occurs during connection, breakage is likely to occur at these points. Compared to conventional tubular rivets, the rivets manufactured using this method have higher mechanical strength, do not damage the original material structure, and have no obvious stress concentration areas.

[0030] When in use, if the upper and lower plates have different thicknesses, the flange should be positioned closer to the thinner side of the plate; if the upper and lower plates have the same thickness but different materials, the flange should be positioned closer to the weaker side of the plate. This allows control over the insertion depth of the tubular rivet, preventing it from piercing thinner or weaker plates. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the flanged tubular rivet manufacturing apparatus of the present invention;

[0032] Figure 2 This is a completed manufacturing drawing of a flanged tubular rivet;

[0033] Figure 3 This is a diagram of the process of connecting flanged tubular rivets for plates with different thicknesses according to the present invention; Figure a shows the initial state of the plate connection, Figure b shows the final rivet insertion state, and Figure c shows the completed plate connection state.

[0034] Figure 4 The diagram shows the process of connecting dissimilar plates using flanged tubular rivets according to the present invention: a is the initial state of connecting dissimilar plates, and b is the state of connecting dissimilar plates after completion.

[0035] Figure 5 These are common problems that occur during conventional riveting connections: a) when connecting plates of unequal thickness, the thinner plate penetrates through the other side; b) when connecting dissimilar materials of equal thickness, the lower-strength plate penetrates through the other side.

[0036] Among them, 1. Upper mold; 2. Flange; 3. Tubular rivet; 4. Lower mold; 5. Upper flat mold; 6. Upper plate; 7. Lower plate; 8. Lower flat mold; 9. Annular protrusion; 10. Stud. Detailed Implementation

[0037] To make the objectives, technical solutions, and advantages of the present invention clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention; that is, the described embodiments are only a part of the embodiments of the present invention, and not all of them.

[0038] The features and performance of the present invention will be further described in detail below with reference to embodiments.

[0039] like Figure 1 As shown, the present invention discloses a manufacturing apparatus for a flanged tubular rivet, including an upper mold 1, a lower mold 4, and a stud 10. The upper mold 1 has an annular protrusion 9 structure at its end, and the lower mold 4 has a threaded through-hole structure inside. Both the upper mold 1 and the lower mold 4 are hollow cylinders. The stud 10 is rotatably connected to the lower mold 4, and the stud 10 can be adjusted up and down. The flanged tubular rivet includes a tubular rivet 3 and a flange 2 connected to the outer circumference of the tubular rivet 3. During processing, part of the tubular rivet 3 is located inside the upper mold 1, and the other part is located inside the lower mold 4. The flange 2 is placed between the annular protrusion 9 structure and the lower mold 4.

[0040] like Figure 1 As shown, the height of the annular protrusion 9 is h0. The height of the annular protrusion 9 is mainly to compress the flange 2 to a certain extent, causing it to undergo plastic deformation. After unloading, it forms a tight contact with the tubular rivet 3. When the height of the annular protrusion 9 is too large, it increases the manufacturing difficulty and cost, and reduces the mold life. When it is too small, the compressed flange 2 remains in the elastic stage after unloading and does not undergo plastic deformation, making it impossible to successfully manufacture the tubular rivet 3 with the flange 2. Therefore, the final design based on the flange 2 thickness t2 is that the height of the annular protrusion 9 is h0 = (1~3)t2.

[0041] The thickness of the annular protrusion 9 is l, which has a significant impact on the area of ​​the extruded flange 2. If the thickness of the annular protrusion 9 is too large, the required extrusion force is greater, which places high demands on the equipment and the hardness of the mold, and it is easy to cause wrinkling after the flange 2 is extruded. If the thickness of the annular protrusion 9 is too small, the area of ​​the extruded flange 2 is smaller, the degree of plastic deformation is lower, the material flows less radially, resulting in less contact with the tubular rivet 3, and the flange 2 formed is easy to fall off. The final design is 0.5mm≤l≤3mm.

[0042] The depth between the lower end face of flange 2 and the bottom end face of tubular rivet 3 is h2, which plays a decisive role in the position of flange 2 on tubular rivet 3. When the depth is too small or too large, the flange 2 is located at both ends of tubular rivet 3. During the insertion of the plate, the plate is prone to pressurizing and dislodging the flange 2, causing the flange 2 to move on tubular rivet 3. The final design is h2 = (0.2~0.7)h1, where h1 is the height of tubular rivet 3.

[0043] The manufacturing method of the manufacturing apparatus for the flanged tubular rivet includes the following steps:

[0044] S1. Determine the appropriate position of flange 2 based on the thickness and material of the upper plate 6 and the lower plate 7 to be connected;

[0045] S2. Adjust the stud 10 up and down to the preset position according to the design requirements;

[0046] The tubular rivet 3 is placed in the countersunk hole formed by the lower die 4 and the stud 10. The flange 2 is fitted on the outside of the tubular rivet 3. The upper die 1 moves downward until it contacts the flange 2 and stops.

[0047] S3. The upper die 1 moves downward at a constant speed V1, pressing the flange 2. The flange 2 undergoes plastic deformation and localized compression occurs at the contact point with the tubular rivet 3. The upper die 1 stops moving downward at a preset position and then moves upward to retract the tubular rivet 3. The tubular rivet 3 elastically recovers and tightly bonds with the flange 2, resulting in a tubular rivet 3 with the flange 2 attached. Figure 2 As shown.

[0048] A gasket can be used as flange 2. The outer diameter of flange 2 is D, which is the specific size of flange 2. When the outer diameter is too large, the volume inserted into the plate is large, the flatness of the joint is reduced, and it has a significant impact on the mechanical properties of the joint. When the outer diameter is too small, it is easy to cause wrinkles on the outside of flange 2 during circumferential extrusion. The final design is D = (1.5~2)d, where d is the outer diameter of the tubular rivet 3.

[0049] The thickness of flange 2 is t2, which directly affects the extrusion amount and the contact with tubular rivet 3. When the thickness is too large, it causes uneven stress distribution and less contact with tubular rivet 3. When it is too small, the extrusion of flange 2 by the annular protrusion 9 makes it difficult for flange 2 to undergo plastic flow, which also leads to less contact with tubular rivet 3. The final design is 0.5mm≤t2≤1.0mm.

[0050] like Figure 1 As shown, the tubular rivet 3 has a height of h1, a wall thickness of t1, an outer diameter of d, and an angle of θ. The dimensions of the tubular rivet 3 have a decisive effect on the mechanical properties and flatness of the joint. When the height h1 is too large, it is easy to pierce the plate, damage the joint, and reduce the mechanical properties. When the height is too small, the stiffness of the tubular rivet 3 increases, and it is not easy to bend and deform when it penetrates the plate, thus reducing the mechanical properties of the joint.

[0051] When the wall thickness t1 of the tubular rivet 3 is too large, the rigidity of the tubular rivet 3 increases, making it more difficult to bend and deform when it is inserted into the plate. When the wall thickness is too small, it is easy for the rivet to become unstable during insertion.

[0052] When the end chamfer θ is too large, it makes it difficult for the end to penetrate the board and cause corresponding bending deformation, resulting in a poor interlocking structure between composite boards. If it is too small, the end is too thin, causing severe bending deformation during penetration, resulting in a low mechanical locking height at the joint and still forming poor joint strength. The final design is h1 = (0.8~1.2)(t 上板材 +t 下板材 ), t 上板材 t 下板材 The thicknesses of the upper plate 6 and the lower plate 7 are respectively 0.5mm≤t1≤2.0mm, and 30°≤θ≤60°.

[0053] Preferably, the tubular rivet 3 and the flange 2 are made of 304 or 316L stainless steel.

[0054] The method for riveting differential thickness plates using the aforementioned flanged tubular rivets includes the following steps:

[0055] Place the upper plate 6 on the upper flat mold 5, and the lower plate 7 on the lower flat mold 8. Place the flanged tubular rivet at the connection position on the lower plate 7, and place the part of the upper plate 6 to be riveted on top of the tubular rivet 3. Figure 3 As shown in Figure a, when the thicknesses of the upper plate 6 and the lower plate 7 are different, the flange 2 is positioned closer to the side of the thinner plate.

[0056] like Figure 3 As shown in b, the lower flat die 8 moves upward at a constant speed V2, pressing the lower plate 7. The upper and lower ends of the tubular rivet 3 respectively penetrate the upper plate 6 and the lower plate 7, and bend and deform within the plates to form a mechanical lock until the surfaces of the upper plate 6 and the lower plate 7 come into contact with each other. The plate connection process is then completed, and the connector is removed. Figure 3 As shown in c.

[0057] The method of using the aforementioned flanged tubular rivets for riveting plates of equal thickness can also achieve the connection of dissimilar materials. For example... Figure 3 As shown, it includes the following steps:

[0058] Place the upper plate 6 on the upper flat mold 5, and the lower plate 7 on the lower flat mold 8. Place the flanged tubular rivet on the lower plate 7, and place the part of the upper plate 6 to be riveted on top of the tubular rivet 3. Figure 4 As shown in a;

[0059] The lower die 8 moves upward at a constant speed V2, pressing the lower plate 7. The upper and lower ends of the tubular rivet 3 respectively penetrate the upper plate 6 and the lower plate 7, and bend and deform within the plates to form a mechanical lock until the surfaces of the upper plate 6 and the lower plate 7 come into contact with each other, completing the plate connection process. Figure 4 As shown in b.

[0060] When the upper plate 6 and the lower plate 7 have the same thickness but different materials, the flange 2 is positioned closer to the side of the plate with weaker hardness.

[0061] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A method for manufacturing a flanged tubular rivet, characterized in that, This is achieved using a manufacturing apparatus for a flanged tubular rivet, the apparatus comprising an upper mold (1), a lower mold (4), and a stud (10); the bottom end structure of the upper mold (1) is an annular protrusion (9); both the upper mold (1) and the lower mold (4) are hollow cylinders; the stud (10) is movably connected to the lower mold (4); the flanged tubular rivet comprises a tubular rivet (3) and a flange (2) connected to the outer circumference of the tubular rivet (3); During processing, part of the tubular rivet (3) is located in the upper mold (1) and the other part is located in the lower mold (4). A flange (2) is placed between the annular protrusion (9) and the lower mold (4). The flange (2) has an outer diameter of D and a thickness of t2, where D = (1.5~2)d, 0.5mm ≤ t2 ≤ 1.0mm, and d is the outer diameter of the tubular rivet (3). The dimension between the lower end face of the flange (2) and the bottom end face of the tubular rivet (3) is h2, and the height of the tubular rivet (3) is h1, h2 = (0.2~0.7)h1; h1 = (0.8~1.2)(t) 上板材 + t 下板材 ), t 上板材 t represents the thickness of the upper plate (6) to be connected. 下板材 The thickness of the lower plate (7) to be connected is t2; the thickness of the flange (2) is t2, and the height of the annular protrusion (9) is h0 = (1~3)t2; The manufacturing method of the flanged tubular rivet includes the following steps: S1. Determine the position of flange (2) based on the thickness and material of the upper plate (6) and lower plate (7) to be connected: When the thicknesses of the upper plate (6) and the lower plate (7) are different, the flange (2) is positioned closer to the side of the thinner plate. When the upper plate (6) and the lower plate (7) have the same thickness but different materials, the flange (2) is located closer to the side of the plate with weaker hardness. S2. Adjust the stud (10) to the preset position, place the tubular rivet (3) in the countersunk hole formed by the lower die (4) and the stud (10), fit the flange (2) on the outer wall of the tubular rivet (3), and fit the upper die (1) on the outside of the upper section of the tubular rivet (3). S3. The upper die (1) moves downward and squeezes the flange (2). The flange (2) undergoes radial plastic deformation and acts on the tubular rivet (3). The upper die (1) stops after moving to the preset position and moves upward to the initial position. Due to the elastic recovery of the tubular rivet (3), a tight connection is formed between the flange (2) and the tubular rivet (3), resulting in a tubular rivet with a flange.

2. The method for manufacturing a flanged tubular rivet according to claim 1, characterized in that, The thickness of the annular protrusion (9) is l 0.5mm≤ l ≤3mm.

3. The method for manufacturing a flanged tubular rivet according to claim 1, characterized in that, The wall thickness of the tubular rivet (3) is t1, 0.5mm≤t1≤2mm.

4. The manufacturing method of a flanged tubular rivet according to claim 1, characterized in that, The tubular rivet (3) has chamfers at both ends. The chamfer at the end of the tubular rivet (3) is θ, 30°≤θ≤60°.

5. A method for manufacturing a flanged tubular rivet according to claim 1, characterized in that, The tubular rivets (3) and flanges (2) are made of 304 or 316L stainless steel.

6. A method for riveting plates with flanged tubular rivets according to any one of claims 1-5, characterized in that, The process includes the following: Place the lower plate (7) on the lower flat mold (8), place the flanged tubular rivet on the lower plate (7) at the connection position, and place the upper plate (6) at the riveting part on the upper part of the tubular rivet (3). When the thickness of the upper plate (6) and the lower plate (7) are different, the flange (2) is located closer to the thinner side of the plate; when the thickness of the upper plate (6) and the lower plate (7) are the same and the materials are different, the flange (2) is located closer to the side with weaker hardness of the plate. The lower flat die (8) moves upward to squeeze the lower plate (7). The upper end of the tubular rivet (3) pierces into the upper plate (6) and the lower end pierces into the lower plate (7), and bends and deforms inside the plate to form a mechanical lock until the surfaces of the upper plate (6) and the lower plate (7) come into contact with each other, and the plate connection process is completed.

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