Convex hull riveting process

Abstract

The invention relates to a convex hull riveting process which comprises the following steps: forming a matching hole in a riveted plate, arranging or not arranging a chamfer at the edge of the matching hole, forming a convex hull protruding towards one side of the riveted plate on the riveted plate, forming a recess between the convex hull and the other side of the riveted plate, and forming a cutter surface inclined towards the center of a punch at the edge of the punch, the method comprises the following steps: supporting a convex hull by matching a top piece with a recess, stacking a riveting plate and a riveted plate until the convex hull penetrates through a matching hole in clearance fit and protrudes out of the matching hole, extruding the convex hull by a punch, shearing or extruding the convex hull by a cutter face until the edge of the convex hull is deformed and is locked with a chamfer or the riveted plate without a chamfer, so that the deformation risk of the riveted plate can be reduced; compared with TOX riveting, the convex hull riveting device has the advantages that the riveting reliability is improved, the applicability of convex hull riveting is further improved, particularly the current situation that convex hull riveting cannot be applied due to the fact that materials of a riveted plate are soft can be solved, the riveting strength can be considered, the press riveting force of a punch is reduced, and compared with TOX riveting, the production cost can be better saved, and the riveting efficiency can be better improved.

Description

Technical Field

[0001] The invention belongs to the technical field of rivet-free riveting, and in particular relates to a convex riveting process. Background Art

[0002] The rivet-free connection technology uses a plate crimping machine and a mold. Through an instantaneous high-pressure processing process, the cold extrusion deformation of the plate material itself is formed to form an internal inlaid dot with a certain tensile and shear strength. It can connect two or more layers of plates of different materials and thicknesses. Compared with welding connection, it has the advantages of a wider range of application of plate materials and thickness differences, lower processing difficulty, etc. Compared with bolt connection or rivet riveting, it has the advantages of no spare parts and higher processing efficiency. It is more suitable for products with high sealing requirements. For example: In the aspect of silent noise reduction of the electronic control housing of new energy vehicles, it is necessary to attach a damping patch to the outer box of the housing to achieve the effect of reducing noise. The damping patch is composed of glue + rubber layer + very thin metal layer. Since the glue is easy to fail with the extension of use time, it is necessary to add screw locking or riveting structure to the damping patch when attaching the damping patch. The rivet-free riveting structure is more reliable than screws and has lower cost. TOX riveting is a type of rivet-free riveting. It can directly rivet two plates by using a forming punch and a forming die. However, TOX riveting has requirements on the thickness of the two products to be riveted to each other. If one of the two plates is too thin, it cannot be riveted. At the same time, an additional positioning structure needs to be added during the press riveting. In order to improve the limitations of TOX riveting, convex hull riveting methods are proposed in the prior art, for example:

[0003] Patent CN206144937U discloses a one-time self-riveting structure and a one-time self-riveting structure forming die. A cylindrical hole and a conical hole are opened on the riveted part. The upper punch is used to press the part to be riveted and stretch it at the cylindrical hole to form a convex bulge. Then, the convex bulge is restricted by the counter-pressing punch of the lower die. After deformation, it fits with the riveted material on the conical surface to form a riveted connection. Compared with TOX riveting, it can reduce the requirement for material thickness. However, its main technical problems are:

[0004] Since the punch is a flat head and the punch diameter is smaller than the outer diameter of the bulge, the bulge is subjected to force to expand and deform outward as a whole during riveting or cannot guide the bulge material to deform, which will cause the riveted plate to deform or be difficult to rivet reliably, especially when the riveted plate is thin, the material hardness is not very high or is composed of multiple layers of materials, or the material hardness of the riveted plate is significantly higher than that of the riveted plate. For example, the riveted part is a hard shell, the riveted part is a damping patch, a bulge is arranged on the shell, a matching hole is arranged on the damping patch, and the bulge and the matching hole are used to rivet the shell and the damping patch. On the one hand, when the bulge is subjected to the pressure of the punch, deformed and squeezed outward during riveting, the material of the damping patch is relatively soft, and the diameter of the matching part of the bottom of the bulge and the damping patch will expand outward at the same time. The deformation of the matching hole will cause the final bulge to fail to form a riveted structure with the damping patch, and the tensile strength and shear strength are poor. On the other hand, the damping patch is composed of multiple layers of materials, and the force and uncontrollable deformation of the damping patch also cause the rubber layer and glue layer of the damping patch around the bulge to peel off, thereby damaging the damping patch.

[0005] Secondly, when the hardness of the riveted plate material is relatively high and the thickness of the riveted plate is relatively low, the height of the bulge formed by stamping is too high, which will cause the bulge or the riveted plate to be easily deformed during riveting. The stamping and riveting of the bulge by the flat punch will cause the expansion and deformation of the bulge material to be larger. It is difficult to form a reliable riveting under a smaller punch riveting force, which increases the production cost and the requirements for riveting equipment.

[0006] In addition, the setting of the tapered hole increases the number of processing steps for the riveted parts. For riveted parts made of thinner materials, in order to reduce the risk of deformation during processing and simplify the process flow, it is more desirable to reduce the requirements for the shape of the matching holes of the riveted parts while maintaining good strength performance after riveting. Summary of the invention

[0007] The present invention aims to solve at least one of the above-mentioned technical problems to a certain extent. The present invention provides a convex riveting process, which can reduce the risk of deformation of the riveted plate, improve the riveting reliability, and further improve the applicability of convex riveting. In particular, it can solve the current situation that the material of the riveted plate is relatively soft and convex riveting cannot be applied, thereby better saving production costs and improving riveting efficiency.

[0008] The technical solution adopted by the present invention to solve its technical problem is:

[0009] A convex hull riveting process, the process comprising:

[0010] Forming a matching hole on the riveted plate, with or without a chamfer at the edge of the matching hole;

[0011] A convex bump is formed on the riveted plate and protrudes toward one side of the riveted plate, and the convex bump and the other side of the riveted plate form a depression;

[0012] A blade face inclined toward the center of the punch is formed on the edge of the punch;

[0013] Use the top piece and the recess to support the bulge, stack the riveted plate and the riveted plate until the bulge passes through the matching hole of the clearance fit and protrudes out of the matching hole, squeeze the bulge with a punch, and shear or squeeze the bulge with the knife surface until the edge of the bulge is deformed and locked with the riveted plate with or without chamfers.

[0014] In a preferred embodiment, the convex hull riveting process includes: providing a chamfer at the edge of the matching hole;

[0015] A groove is formed in the center of the punch, and the blade surface and the peripheral edge of the groove form a blade edge;

[0016] When the punch squeezes the bulge, the chamfer is located on the side of the riveted plate away from the riveted plate, and the inner edge of the bulge is sheared by the blade until the cut material of the bulge expands and deforms outward along the blade surface and locks with the chamfer.

[0017] In a preferred embodiment, the depth of the groove is greater than the height of the convex hull protruding from the matching hole, and the blade angle is greater than 60°.

[0018] In a preferred embodiment, the convex hull riveting process includes: when the material hardness of the riveted plate is greater than or equal to the material hardness of the riveted plate, and the height of the hull protruding from the matching hole is less than 0.5 mm, a chamfer can be provided at the edge of the matching hole, a flat head is formed at the center of the punch, and a blade surface is provided circumferentially around the flat head;

[0019] When the punch extrude the bulge, the chamfer is located at the side of the riveted plate away from the riveted plate, and the center of the bulge is extruded by the flat head until the bulge expands and deforms outwards along the blade surface and locks with the chamfer.

[0020] In a preferred embodiment, the blade angle is 90-120°.

[0021] In a preferred embodiment, the convex hull riveting process includes: when the material hardness of the riveted plate is greater than or equal to the material hardness of the riveted plate, and the height of the hull protruding from the matching hole is greater than or equal to 0.5 mm, the edge of the matching hole may not be chamfered, the blade surface extends from the edge of the punch to the center of the punch, and the center of the punch forms a tip;

[0022] When the punch squeezes the bulge, the tip squeezes the center of the bulge until the bulge expands and deforms outward along the knife surface and locks with the riveted plate.

[0023] In a preferred embodiment, the diameter of the punch is greater than the inner diameter of the matching hole + 1 mm.

[0024] A convex riveting structure comprises a riveting plate and a riveted plate, wherein the riveting plate and the riveted plate are formed by riveting using any one of the convex riveting processes described above.

[0025] A convex riveting device comprises a punch and a top piece operated according to any one of the convex riveting processes described above.

[0026] In a preferred embodiment, the convex riveting device comprises a support platform and an elastic support member, and the support platform and the elastic support member are used to support the riveting plate and the riveted plate from both sides.

[0027] Compared with the prior art, the beneficial effects of the present invention are at least:

[0028] (1) By forming a blade surface inclined toward the center of the punch at the edge of the punch, a shearing effect can be formed when the punch squeezes the bulge. Compared with the punching of a flat punch, the blade surface structure can guide the bulge material to expand outward, so that the cut bulge material spreads and expands and deforms around along the shape of the blade surface inclined to the edge of the punch. The deformed material of the bulge is locked with the chamfered or unchamfered riveted plate to form a riveted joint, which can solve the problem that the existing bulge riveting process easily causes the riveted plate to deform or is difficult to reliably rivet, and is suitable for products with high sealing requirements.

[0029] (2) Especially when the riveted plate is thin, the material hardness is not very high or it is composed of multiple layers of materials, or the material hardness of the riveted plate is significantly higher than that of the riveted plate, the blade formed by the blade face and the groove can be further used. By using the principle of sharp angle cutting, the convex bulge is changed from being subjected to overall force to being subjected to local force, so as to avoid the expansion and deformation of the riveted plate, and form a more reliable locking structure with the chamfer and the deformed convex bulge edge. The larger the blade angle and the larger the locking diameter formed, the higher the tensile strength. The technical requirements of the riveted material can be selected, and even 180° flat head direct pressure riveting can be used. It has unique advantages in riveting soft materials and can further improve the applicability of the convex bulge riveting process.

[0030] (3) When the hardness of the material of the riveted plate is high, the height of the convex bulge protruding from the matching hole can be further determined by using a punch with a flat center head and a knife face at the edge or by not setting a chamfer on the matching hole and using a knife face extending from the punch edge to the punch center to form a tip-extruded bulge. This can take into account the riveting strength and reduce the punch riveting force compared to TOX riveting, or reduce the requirements for the shape of the matching hole of the riveted parts, thereby better saving production costs.

[0031] (4) The present invention is the same as TOX riveting, both of which belong to rivet-free riveting, but the matching holes and convex bumps can be used as positioning structures. Compared with TOX riveting, no additional positioning tooling is required, and it can also be applied to the situation where the thickness of the riveted plate is less than the thickness of the riveted plate.

[0032] (5) Compared with TOX riveting which can only be used on servo presses and gas-liquid boosters, the present invention has low requirements on riveting equipment and can be used in conjunction with punch presses, hydraulic presses, servo presses, and gas-liquid boosters. Multiple pairs of punches and top pieces can be set to simultaneously rivet multiple riveting points, which significantly improves the riveting efficiency compared to TOX riveting. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0034] Figure 1 is a cross-sectional structural diagram of a riveted plate and a riveted plate before riveting in Example 1 of the present invention;

[0035] Figure 2 It is a schematic diagram of the assembly of the riveted plate and the riveted plate before riveting in Example 1 of the present invention;

[0036] Figure 3 is a schematic diagram of riveting a riveted plate and a riveted plate according to Embodiment 1 of the present invention;

[0037] Figure 4 This is a diagram of the convex hull riveting structure after riveting in Example 1 of the present invention;

[0038] Figure 5 is a cross-sectional structural diagram of a riveted plate and a riveted plate before riveting in Example 2 of the present invention;

[0039] Figure 6 is a schematic diagram of the assembly of the riveted plate and the riveted plate before riveting in Example 2 of the present invention;

[0040] Figure 7 is a schematic diagram of riveting a riveted plate and a riveted plate according to Embodiment 2 of the present invention;

[0041] Figure 8 This is a diagram of the convex hull riveted structure after riveting in Example 2 of the present invention;

[0042] Fig. 9 is a cross-sectional structural diagram of a riveted plate and a riveted plate before riveting in Example 3 of the present invention;

[0043] Fig.10 is a schematic diagram of the assembly of the riveted plate and the riveted plate before riveting in Example 3 of the present invention;

[0044] Fig.11 is a schematic diagram of riveting a riveted plate and a riveted plate according to Embodiment 3 of the present invention;

[0045] Fig.12 is a diagram of the convex hull riveting structure after riveting in Example 3 of the present invention;

[0046] Fig.13It is a structural diagram of a convex riveting device according to embodiment 4 of the present invention.

[0047] Markings in the figure: riveted plate 1, matching hole 101, chamfer 102, riveted plate 2, convex 201, concave 202, punch 3, knife surface 301, groove 302, knife edge 303, flat head 304, tip 305, ejector 4; upper die 5, lower die 6, guide sleeve 7, PU glue 8, support platform 9, guide column 10, lower ejector pin 11. DETAILED DESCRIPTION

[0048] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0049] In the description of the present invention, it should be understood that the terms "center", "thickness", "upper", "lower", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In the description of the present invention, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0050] Embodiment 1:

[0051] In view of the current situation that TOX riveting as a rivet-free riveting method is lower in cost and simpler in processing than screw or rivet riveting, it cannot be used when the riveted plate is thinner than the riveted plate, and the existing convex hull riveting process is easy to cause the riveted plate to deform or difficult to rivet reliably. Figures 1 to 4 As shown, a preferred embodiment of the convex riveting process of the present invention is shown, and the process includes:

[0052] Step 1:

[0053] like Figure 1As shown, a matching hole 101 is formed on the riveted plate 1, and a chamfer 102 is set at the edge of the matching hole 101, for example, the matching hole 101 with the chamfer 102 is punched out on the riveted plate 1 by punching or milling; a convex 201 protruding toward one side of the riveted plate 2 is formed on the riveted plate 2, and the convex 201 forms a concave 202 with the other side of the riveted plate 2, for example, a convex 201 is punched out on the riveted plate 2 by stamping, and the diameter M of the convex 201 is greater than 3 mm, the inner diameter K of the matching hole 101 satisfies K=M+0.05-0.1mm, so that in the subsequent pressure riveting, after the convex bump 201 extends into the matching hole 101, the convex bump 201 and the matching hole 101 can form a clearance fit, the matching hole 101 and the convex bump 201 can be used as a positioning structure, and no additional positioning tooling is required compared to TOX riveting. Since the riveted plate 1 will not be folded as in TOX riveting, it can also be applied to the situation where the thickness L of the riveted plate 1 is less than the thickness H of the riveted plate 2.

[0054] Step 2:

[0055] like Figure 2 As shown, a blade surface 301 inclined toward the center of the punch 3 is formed at the edge of the punch 3, for example: the diameter C of the punch 3 is slightly larger than the inner diameter K of the matching hole 101, preferably C>K+1mm, and a blade surface 301 is formed by providing a guide chamfer at the edge of the punch 3, and the angle of the blade surface 301, that is, the angle of the guide chamfer is>60°. Since the blade surface 301 extends obliquely to the outer edge of the punch 3, it is beneficial for the subsequent riveting process so that the material of the bulge 201 can be quickly sheared and expanded and deformed outward along the shape of the guide chamfer to fit the chamfer 102 of the matching hole 101, avoiding the risk of an angle being too small and too sharp, the risk of the riveting strength being lost due to the root of the material cut out by the bulge 201 being too thin and easy to break, or the risk of increasing the impact on the riveted plate 1 and causing deformation of the matching hole 101 due to too much material cut out by the bulge 201.

[0056] A groove 302 is formed in the center of the punch 3, and the blade surface 301 and the circumferential edge of the groove 302 form a cutting edge 303. For example, the middle of the punch 3 is hollowed out to form a groove 302, and the depth G of the groove 302 is greater than the height H of the bulge 201 protruding from the matching hole 101. The inner diameter D of the groove 302 is slightly smaller than the inner diameter K of the matching hole 101, preferably D=K-2mm, so that in the subsequent riveting process, the cutting edge 303 can cut into the inner edge of the bulge 201, and the groove 302 can be formed to accommodate the material that is not cut out of the bulge 201.

[0057] The ejector 4 cooperates with the recess 202 to support the convex hump 201, and the riveted plate 2 and the riveted plate 1 are stacked until the convex hump 201 passes through the matching hole 101 with clearance and protrudes from the matching hole 101, and the chamfer 102 is located on the side of the riveted plate 1 away from the riveted plate 2. For example, the ejector pin protrudes from the riveted plate 2 and is placed inside the recess 202 to support the bottom of the convex hump 201, so that the convex hump 201 protrudes upward, and is aligned downward through the matching hole 101. The riveted plate 1 is stacked on top of the riveted plate 2, so that the riveted plate 1 and the riveted plate 2 are positioned and assembled through the clearance between the convex hump 201 and the matching hole 101, and the chamfer 102 of the matching hole 101 is located on the upper part of the riveted plate 2, preparing for subsequent pressure riveting.

[0058] Step 3:

[0059] like Figure 3 As shown, the punch 3 is used to squeeze the convex 201, the blade surface 301 shears or squeezes the convex 201, and the blade edge 303 shears the inner edge of the convex 201 until the edge of the convex 201 is deformed, that is, the cut material of the convex 201 expands and deforms outward along the blade surface 301 and locks with the chamfer 102. For example, when the punch 3 squeezes the convex 201 downward, the principle of sharp angle cutting is adopted, and the blade edge 303 formed by the blade surface 301 and the groove 302 is used to cut a circle around the convex 201 during downward pressing. In this way, only the position around the convex 201 is cut, and the material not cut out is accommodated in the groove 302. Compared with the punching of the flat punch, the convex hump 201 is not expanded outward as a whole under force, but only locally under force, thereby preventing the convex hump 201 from expanding and deforming as a whole due to the force on the force-bearing surface diameter of the convex hump 201 and the riveted plate 1. At the same time, when the convex hump 201 is cut at the acute angle of the blade 303, the blade surface 301 structure can guide the material to expand outward, so that the cut convex hump 201 material spreads and expands and deforms around along the shape of the blade surface 301 inclined to the edge of the punch 3, so that the chamfer 102 and the deformed convex hump 201 edge form a more reliable locking structure, thereby forming a stable riveting.

[0060] After removing the punch 3 and the top piece 4, the convex riveting structure is as follows Figure 4 As shown, the convex rivet structure includes a riveting plate 2 and a riveted plate 1. The riveted plate 2 is matched with the inner wall of the matching hole 101 through the gap between the outer wall of the convex 201 and the inner wall of the matching hole 101. The end of the convex 201 is cut and extruded to deform, and the material flows to the chamfer 102 that fills the matching hole 101 to form a riveted connection. Compared with the existing convex rivet structure, the deformed part of the convex 201 has less material and is closer to the chamfer 102, which effectively solves the problem that the existing convex riveting process easily causes the riveted plate 1 to deform or is difficult to rivet reliably, and in particular, it can solve the current situation that the material of the riveted plate 1 is relatively soft and the convex rivet cannot be applied:

[0061] Taking the riveted plate 1 as a damping patch composed of glue + rubber layer + thin metal layer, the damping patch material is relatively soft, and the riveted plate 2 is a hard shell as an example, the above-mentioned convex hull riveting process can form a very good riveted structure when press-riveting the damping patch, and at the same time, there is no extrusion expansion deformation around the damping patch hole. In the comparative test of riveting of the same material between Example 1 and the TOX riveting process, the tensile strength and shear strength of the riveted structure are better than those of TOX riveting, and the punch riveting force in the riveting process is lower than that of TOX riveting, which can better save production costs. It can be seen that the above-mentioned convex hull riveting process has unique advantages in riveting soft materials, and can further improve the applicability of the convex hull riveting process.

[0062] Embodiment 2:

[0063] In view of the limitation of the thickness of the riveted products of TOX riveting in the prior art, and the fact that the existing convex hull riveting process easily causes the riveted plate to deform or is difficult to form a reliable riveting under a small punch pressure, when the material hardness of the riveted plate is greater than or equal to the material hardness of the riveted plate, and the height of the hull protruding from the matching hole is less than 0.5mm, Figures 5 to 8 As shown, another preferred embodiment of the convex riveting process of the present invention is shown, and the process includes:

[0064] Step 1:

[0065] like Figure 5 As shown, a matching hole 101 is formed on the riveted plate 1, and a chamfer 102 is set at the edge of the matching hole 101, for example: the matching hole 101 with the chamfer 102 is punched out on the riveted plate 1 by punching or milling, the cylindrical hole height of the matching hole 101 is J, and the angle of the chamfer 102 is 90°; a convex 201 protruding toward one side of the riveted plate 2 is formed on the riveted plate 2, and the convex 201 and the other side of the riveted plate 2 form a concave 202, for example: A convex hump 201 is punched out on the riveted plate 2 by stamping, the diameter of the convex hump 201 is M, the height of the convex hump 201 protruding from the riveted plate 2 is H, HJ>0.5mm, and the inner diameter K of the matching hole 101 satisfies K=M+0.05~0.1mm, so that the convex hump 201 and the matching hole 101 can form a clearance fit and improve the positioning accuracy, while leaving enough space for the deformation and filling of the convex hump 201 material at the chamfer 102 to improve the riveting strength.

[0066] Step 2:

[0067] like Figure 6As shown, a blade face 301 inclined toward the center of the punch 3 is formed at the edge of the punch 3, a flat head 304 is formed at the center of the punch 3, and the blade face 301 is arranged circumferentially around the flat head 304. For example, the diameter C of the punch 3 is slightly larger than the inner diameter K of the matching hole 101, preferably C>K+1mm, the diameter D of the flat head 304 is slightly smaller than the inner diameter K of the matching hole 101, preferably D=K-1mm, and the blade face 301 is formed by providing a guide chamfer at the edge of the punch 3. The included angle of the blade face 301, i.e., the angle of the guide chamfer, is 90° to 120°, since the blade surface 301 extends obliquely from the center flat head 304 to the outer edge of the punch 3, it is beneficial for the material of the bulge 201 to expand and deform outward along the shape of the guide chamfer in the subsequent riveting process to fit the chamfer 102 of the matching hole 101, avoiding the risk of the angle being too sharp due to the bulge 201 cutting out too much material and increasing the impact on the riveted plate 1 and causing the matching hole 101 to deform due to the bulge 201 being too large, thereby avoiding the bulge 201 expanding too little material and reducing the riveting strength.

[0068] The ejector 4 cooperates with the recess 202 to support the convex hump 201, and the riveted plate 2 and the riveted plate 1 are stacked until the convex hump 201 passes through the matching hole 101 with clearance and protrudes from the matching hole 101, and the chamfer 102 is located on the side of the riveted plate 1 away from the riveted plate 2. For example, the ejector pin protrudes from the riveted plate 2 and is placed inside the recess 202 to support the bottom of the convex hump 201, so that the convex hump 201 protrudes upward, and is aligned downward through the matching hole 101. The riveted plate 1 is stacked on top of the riveted plate 2, so that the riveted plate 1 and the riveted plate 2 are positioned and assembled through the clearance between the convex hump 201 and the matching hole 101, and the chamfer 102 of the matching hole 101 is located on the upper part of the riveted plate 2, preparing for subsequent pressure riveting.

[0069] Step 3:

[0070] like Figure 7 As shown, the convex 201 is squeezed by the punch 3, the center of the convex 201 is squeezed by the flat head 304, and the convex 201 is sheared or squeezed by the blade surface 301 until the edge of the convex 201 is deformed, that is, until the sheared material of the convex 201 expands and deforms outward along the blade surface 301 and locks with the chamfer 102. For example: when the punch 3 squeezes the convex 201 downward, compared with the stamping of the flat head punch, the blade surface 301 structure can guide the material to expand outward, so that the cut convex 201 material spreads, expands and deforms around along the shape of the blade surface 301 inclined to the edge of the punch 3, fills the gap between the chamfer 102 and the blade surface 301, so that the chamfer 102 and the deformed convex 201 edge form a more reliable locking structure, thereby forming a stable riveting.

[0071] After removing the punch 3 and the top piece 4, the convex riveting structure is as follows Figure 8As shown, the convex hump riveting structure includes a riveting plate 2 and a riveted plate 1. The riveted plate 2 is matched with the inner wall of the matching hole 101 through the gap between the outer wall of the convex hump 201 and the inner wall of the matching hole 101. The end of the convex hump 201 is deformed by being squeezed and the material flows obliquely to the chamfer 102 that fills the matching hole 101 to form a riveted connection. Compared with the existing convex hump riveting structure, the deformed part of the convex hump 201 has less material and is closer to the chamfer 102, which effectively solves the problem that the existing convex hump riveting process easily causes the riveted plate 1 to deform or is difficult to rivet reliably.

[0072] In the comparative test of riveting of the same material between Example 1, Example 2 and TOX riveting process, the tensile strength of the convex rivet structure obtained by the convex rivet process of Example 2 is slightly lower than that of TOX riveting by about 10%, and the shear strength is equivalent, but the punch riveting force is lower than that of TOX riveting. Through the matching hole 101 and the convex 201, no additional positioning tooling is required compared with TOX riveting, and the riveted plate 1 has a high positioning accuracy, and the punch 3 is not easily damaged and more durable. The punch riveting force of Example 1 is about 30% of the punch riveting force of Example 2, which can better save production costs. The larger the angle of the guide chamfer in Example 1, the larger the lock buckle diameter formed by the deformation of the convex 201 material, and the higher the tensile strength, which can be selected according to the technical requirements of the riveted material, and even a 180° flat head 304 can be used for direct riveting as in Example 2.

[0073] Embodiment 3:

[0074] In view of the limitation of the thickness of the riveted products of TOX riveting in the prior art, the existing convex hull riveting process is easy to cause the riveted plate to deform or it is difficult to form a reliable riveting under a small punch pressure, and the setting of the conical hole increases the number of processes. When the material hardness of the riveted plate is greater than the material hardness of the riveted plate, and the height of the hull protruding from the matching hole is greater than 0.5mm, Figures 9 to 12 As shown, another preferred embodiment of the convex riveting process of the present invention is shown, and the process includes:

[0075] Step 1:

[0076] like Fig. 9As shown, a matching hole 101 is formed on the riveted plate 1, and no chamfer 102 is set on the edge of the matching hole 101. For example, a cylindrical matching hole 101 is punched out on the riveted plate 1 by punching or milling. A convex 201 protruding toward one side of the riveted plate 2 is formed on the riveted plate 2, and the convex 201 forms a recess 202 with the other side of the riveted plate 2. For example, a convex 201 is punched out on the riveted plate 2 by stamping, and the diameter M of the convex 201 is greater than 3mm. The inner diameter K of the matching hole 101 satisfies K=M+0.05~0.1mm, so that the subsequent During the pressure riveting, after the convex hump 201 extends into the matching hole 101, the convex hump 201 and the matching hole 101 can form a clearance fit, and the matching hole 101 and the convex hump 201 can be used as a positioning structure. Compared with TOX riveting, no additional positioning tooling is required. Since the riveted plate 1 will not be folded as in TOX riveting, it can also be applied to the situation where the thickness L of the riveted plate 1 is less than the thickness H of the riveted plate 2. Compared with the existing convex hump riveting process, it is not necessary to set the chamfer 102 on the matching hole 101, which can simplify the processing of the riveted plate 1 and is more suitable for the situation where the riveted plate 1 is thin and is not suitable for the chamfer 102.

[0077] Step 2:

[0078] like Fig.10 As shown, a blade surface 301 inclined toward the center of the punch 3 is formed on the edge of the punch 3, and the blade surface 301 extends from the edge of the punch 3 to the center of the punch 3, and a tip 305 is formed in the center of the punch 3. For example, the diameter C of the punch 3 is slightly larger than the inner diameter K of the matching hole 101, preferably C>K+1mm, and the blade surface 301 and the tip 305 are formed on the edge of the punch 3 by opening a guide chamfer extending to the center of the tap. The height of the blade surface 301 is 0.5mm. Since the blade surface 301 extends obliquely to the outer edge of the punch 3, it is beneficial to enable the convex hump 201 material to be quickly sheared and expand and deform outward along the shape of the guide chamfer to fit the riveted plate 1 during the subsequent riveting process.

[0079] The ejector 4 cooperates with the recess 202 to support the convex hump 201, and the riveted plate 2 and the riveted plate 1 are stacked until the convex hump 201 passes through the matching hole 101 with clearance fit and protrudes from the matching hole 101, and the chamfer 102 is located on the side of the riveted plate 1 away from the riveted plate 2. For example, the ejector pin protrudes from the riveted plate 2 and is placed inside the recess 202 to support the bottom of the convex hump 201. The diameter of the recess 202 is B, and the ejector pin diameter A=B-0.005~0.1mm, which plays a positioning and supporting role to prevent the convex hump 201 from being squeezed down by the punch 3 during the forming process and unable to form, so that the convex hump 201 protrudes upward, and is aligned downward with the convex hump 201 through the matching hole 101, and the riveted plate 1 is stacked on the riveted plate 2, so that the riveted plate 1 and the riveted plate 2 are positioned and assembled through the clearance fit between the convex hump 201 and the matching hole 101, so as to prepare for subsequent pressure riveting.

[0080] Step 3:

[0081] like Fig.11 As shown, the convex 201 is squeezed by the punch 3, the center of the convex 201 is squeezed by the tip 305, and the convex 201 is sheared or squeezed by the blade 301 until the edge of the convex 201 is deformed, and the convex 201 is expanded and deformed outward along the blade 301 and locked with the riveted plate 1. For example, when the punch 3 squeezes the convex 201 downward, the convex 201 is squeezed from the center to the surrounding during the downward pressing. Compared with the punching with a flat punch or a punch with a protruding center, since the blade 301 extends obliquely from the center tip 305 to the edge of the punch 3, the blade 301 structure can guide the material to expand outward, so that the cut convex 201 material diffuses and expands and deforms along the inclination to the surrounding, so that the edge of the deformed convex 201 forms a more reliable locking structure with the riveted plate 1, and thus a stable riveting can be formed when the matching hole 101 is not provided with a chamfer 102.

[0082] After removing the punch 3 and the top piece 4, the convex riveting structure is as follows Fig.12 As shown, the convex hump riveting structure includes a riveting plate 2 and a riveted plate 1. The riveted plate 2 is matched with the inner wall of the matching hole 101 through the gap between the outer wall of the convex hump 201 and the inner wall of the matching hole 101. The end of the convex hump 201 is deformed by being squeezed and the material flows obliquely to the plate surface of the riveted plate 1 close to the outside of the matching hole 101 to form a riveted connection. Compared with the existing convex hump riveting structure, the deformed part of the convex hump 201 has less material, and the deformation covers the matching hole 101 more evenly and reliably, which effectively solves the problem that the existing convex hump riveting process easily causes the riveted plate 1 to deform or is difficult to rivet reliably.

[0083] In the comparative test of the riveting of the same material between Example 1, Example 3 and TOX riveting process, the tensile strength of the convex rivet structure obtained by the convex rivet process of Example 3 is slightly lower than that of TOX riveting by about 10%, and the shear strength is equivalent, but the punch riveting force is lower than that of TOX riveting. Through the matching hole 101 and the convex 201, no additional positioning tool is required compared with TOX riveting, and the riveted plate 1 has a high positioning accuracy, and the matching hole 101 does not need to be provided with a chamfer 102, and the processing is simpler; the punch riveting force of Example 1 is 30 %, which can better save production costs. At the same time, compared with Example 1, when the convex bulge 201 of Example 2 and Example 3 expands outward when squeezed, if the hardness of the material of the riveted plate 1 is not very high, there is a risk of simultaneous expansion and deformation of the bottom of the convex bulge 201 and the diameter of the matching part of the riveted plate 1. Therefore, it is more suitable for the situation where the hardness of the material of the riveted plate 1 is greater than or equal to the hardness of the material of the riveted plate 2. According to the hardness, thickness, composition or processing difficulty of the riveted plate 2 and the riveted plate 1, the height of the convex bulge 201 protruding from the matching hole 101 is different, and the riveting process can be selected according to the needs.

[0084] Embodiment 4:

[0085] A convex riveting device includes a punch 3 and a top piece 4 operated according to the convex riveting process as described in any one of Examples 1 to 3. During the riveting process, the matching hole 101 and the convex hump 201 can be used as a positioning structure. Compared with the TOX riveting device, no additional positioning tooling is required, which can better save production costs.

[0086] In a preferred embodiment, the convex riveting device comprises a support platform 9 and an elastic support member, and the support platform 9 and the elastic support member are used to support the riveting plate 2 and the riveted plate 1 from both sides, for example:

[0087] like Fig.13 As shown, taking the elastic support member as the high-strength rubber 8 as an example, the convex riveting device includes an upper die 5 and a lower die 6 that cooperate to open and close, the upper die 5 is provided with a guide sleeve 7, the high-strength rubber 8 and a forming punch 3, the guide sleeve 7 is arranged on both sides of the upper die 5, the punch 3 is arranged inside the high-strength rubber 8 and can be extended and retracted relative to the high-strength rubber 8, the lower die 6 is provided with a support platform 9 and a guide column 10, the support platform 9 is provided with a protruding lower ejector pin 11, the lower ejector pin 11 is used as the ejector 4, and the guide column 10 is located on both sides of the lower die 6 and can slide and cooperate with the guide sleeve 7 for guidance. When the convex hump is riveted, the die is opened first, and the punch 3 is retracted inside the cylindrical rubber 8. The riveted plate 2 with the convex hump 201 can be placed on the support platform 9, and the lower ejector pin 11 is positioned with the depression 202 of the matching convex hump 201. The support platform 9 positions and supports the riveted plate 2, and the riveted plate 1 with the matching hole 101 is positioned and placed above the riveted plate 2 through the matching hole 101 and the convex hump 201.

[0088] When the upper die 5 is pressed down, the guide sleeve 7 and the guide column 10 cooperate to guide the stable stamping, so that the rubber 8 first contacts the riveted plate 1, and the rubber 8 elastically supports the riveted part. As the upper die 5 continues to be pressed down, the punch 3 can be detached and replaced, and the structure is not fixed. The design can be selected according to the actual situation. For details, the punch 3 structure of embodiments 1 to 3 can be referred to. The punch 3 punches the convex 201 downward to perform riveting forming. During the forming process, the rubber 8 plays a role in pressing the riveted plate 2 and the riveted plate 1 tightly together, and it is also beneficial to In order to prevent the riveted plate 1 from deforming during the riveting process, the elastic support member in some special structures can also be designed by connecting a vertically placed spring with an iron plate. The advantage of the rubber 8 is that it has a simple structure and is more cost-effective. The lower ejector pin 11 serves as a positioning support for the bulge 201 during molding to prevent the bulge 201 from being squeezed down by the molding punch 3 during the molding process and unable to be molded. After riveting, the upper mold 5 moves upward to drive the punch 3 to separate from the bulge 201, and the riveted product can be removed from the lower mold 6.

[0089] TOX riveting requires a relatively large riveting force and can only be used on a servo press and a gas-liquid booster. The drive of the punch 3 of the present application includes a punch press, a hydraulic press, a servo press, and a gas-liquid booster, and the requirements for the riveting equipment are not very high. According to the riveting requirements, multiple pairs of punches 3 and top pieces 4 can be set to press and rivet simultaneously, and then multiple riveting points can be riveted at the same time. The riveting points on the same plane can be riveted simultaneously on a set of tooling, so the riveting efficiency is several times that of TOX riveting.

[0090] The series of detailed descriptions listed above are only specific descriptions of feasible embodiments of the present invention, and they are not intended to limit the scope of protection of the present invention. For example, the riveting force needs to be actually defined according to the actual riveting test conditions. All equivalent embodiments or changes that do not deviate from the technical spirit of the present invention should be included in the scope of protection of the present invention.

Claims

1. A convex riveting process, characterized in that: The process includes: A matching hole (101) is formed on the riveted plate (1), and a chamfer (102) is provided or not provided on the edge of the matching hole (101); A convex bump (201) protruding toward one side of the riveted plate (2) is formed on the riveted plate (2), and the convex bump (201) and the other side of the riveted plate (2) form a concave depression (202); A blade surface (301) inclined toward the center of the punch (3) is formed on the edge of the punch (3); The top piece (4) and the recess (202) are used to cooperate to support the convex bump (201), and the riveted plate (2) and the riveted plate (1) are stacked until the convex bump (201) passes through the matching hole (101) with clearance fit and protrudes out of the matching hole (101), and the convex bump (201) is pressed by the punch (3), and the convex bump (201) is sheared or pressed by the blade (301) until the edge of the convex bump (201) is deformed and locked with the riveted plate (1) with or without a chamfer (102).

2. The convex riveting process according to claim 1, characterized in that: A chamfer (102) is provided on the edge of the matching hole (101); A groove (302) is formed at the center of the punch (3), and a cutting edge (303) is formed between the blade surface (301) and the peripheral edge of the groove (302); When the punch (3) squeezes the bulge (201), the chamfer (102) is located on the side of the riveted plate (1) away from the riveted plate (2), and the inner edge of the bulge (201) is sheared by the blade (303) until the cut material of the bulge (201) expands and deforms outwards along the blade surface (301) and locks with the chamfer (102).

3. The convex hull riveting process according to claim 2, characterized in that: The depth of the groove (302) is greater than the height of the convex bump (201) protruding from the matching hole (101), and the included angle of the blade surface (301) is greater than 60°.

4. The convex riveting process according to claim 1, characterized in that: When the material hardness of the riveted plate (1) is greater than or equal to the material hardness of the riveted plate (2), and the height of the convex bump (201) protruding from the matching hole (101) is less than 0.5 mm, a chamfer (102) can be provided at the edge of the matching hole (101), a flat head (304) is formed at the center of the punch (3), and the blade surface (301) is circumferentially arranged around the flat head (304); When the punch (3) squeezes the convex bump (201), the chamfer (102) is located on the side of the riveted plate (1) away from the riveted plate (2), and the flat head (304) squeezes the center of the convex bump (201) until the convex bump (201) expands and deforms outwards along the blade surface (301) and locks with the chamfer (102).

5. The convex hull riveting process according to claim 4, characterized in that: The included angle of the blade surface (301) is 90-120°.

6. The convex riveting process according to claim 1, characterized in that: When the material hardness of the riveted plate (1) is greater than or equal to the material hardness of the riveted plate (2), and the height of the convex bump (201) protruding from the matching hole (101) is greater than or equal to 0.5 mm, the edge of the matching hole (101) may not be provided with a chamfer (102), and the blade surface (301) extends from the edge of the punch (3) to the center of the punch (3), and a tip (305) is formed in the center of the punch (3); When the punch (3) squeezes the convex bump (201), the tip (305) squeezes the center of the convex bump (201) until the convex bump (201) expands and deforms outwards along the blade surface (301) and is locked with the riveted plate (1).

7. A convex riveting structure, comprising a riveting plate (2) and a riveted plate (1), characterized in that: The riveted plate (2) and the riveted plate (1) are formed by riveting using the convex riveting process described in any one of claims 1 to 6.

8. A convex riveting device, characterized in that: It comprises a punch (3) and a top piece (4) operated according to the convex riveting process described in any one of claims 1 to 6.

9. The convex riveting device according to claim 8, characterized in that: It comprises a support platform (9) and an elastic support member, wherein the support platform (9) and the elastic support member are used to support the riveting plate (2) and the riveted plate (1) from both sides.

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