Riveting piece, riveting structure, riveting die structure and riveting equipment

Abstract

The utility model provides a riveting piece, a riveting structure, a riveting die structure and riveting equipment. The riveting piece comprises a riveting tail portion, a riveting waist portion and a riveting head portion which are sequentially arranged in the first direction. The outer diameter of the section, perpendicular to the first direction, of the riveting head is smaller than that of the section, perpendicular to the first direction, of the riveting tail; in the outer diameter of the section, perpendicular to the first direction, of the riveting waist part, the part close to the riveting head part is smaller than the outer diameter of the section, perpendicular to the first direction, of the riveting head part, and the part close to the riveting tail part is located between the outer diameter of the section, perpendicular to the first direction, of the riveting head part and the outer diameter of the section, perpendicular to the first direction, of the riveting tail part. In the utility model, when the riveting is finished, the riveting tail part is pressed on the uppermost plate material of the material plate, the riveting waist part is arranged in the material plate in a penetrating manner, and the riveting head part is pressed on the lowermost plate material of the material plate, so that the riveting tail part and the riveting head part clamp the part material plate, a firm mechanical interlocking structure is formed in the material plate, and the cracking is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of riveting structures, in particular to a riveting piece, a riveting structure, a riveting die structure and a riveting device. Background Art

[0002] In recent years, with the emergence of steel-aluminum hybrid car bodies, some new connection technologies, such as SPR semi-hollow riveting technology, have been rapidly promoted and applied in the automotive industry. The SPR riveting process is: under the pressure of the rivet gun equipment, the rivet pierces the upper plate and drives the plate to be pressed into the riveting die, and the nail foot deforms and opens to insert into the bottom plate, forming an interlock with the plate to achieve connection. Its application is relatively limited, mainly in two aspects:

[0003] First: SPR riveting generally requires that the riveted material (such as rivets) be aluminum alloy or very low-strength carbon steel to meet the needs of opening and forming during SPR riveting, but there will be insufficient strength and it will not be able to pierce high-strength steel or hot-formed steel and other sheet materials.

[0004] Second: In order to avoid cracking during SPR riveting, the bottom plate material can only be aluminum alloy. The main reason is that during riveting, the bottom aluminum alloy material will undergo significant tensile deformation. According to industry experience, in order to avoid cracking during riveting of the bottom plate, the elongation of the bottom aluminum alloy material is generally required to be greater than or equal to 12%. Actual measurements show that for an ideal combination of material, thickness, and overlap sequence, the elongation of the bottom plate material is above 10%, which is basically feasible by optimizing the riveting die structure and riveting process parameters. If the elongation is between 8% and 10%, riveting will be very difficult. Even with a better combination, microcracks will still appear on the bottom plate after riveting, and defects such as insufficient rivet interlocking will occur, and the fatigue durability of the rivet point will be reduced. Utility Model Content

[0005] The utility model provides a riveting piece, a riveting structure, a riveting die structure and a riveting device, so as to solve the problem that the existing riveting piece is prone to riveting cracks when in use.

[0006] A riveted part, comprising a riveted tail, a riveted waist and a riveted head arranged in sequence along a first direction;

[0007] The outer diameter of the cross section of the rivet head along the direction perpendicular to the first direction is smaller than the outer diameter of the cross section of the rivet tail along the direction perpendicular to the first direction;

[0008] Among the cross-sectional outer diameters of the riveted waist along the first direction perpendicular to the first direction, the portion close to the riveted head is smaller than the cross-sectional outer diameter of the riveted head along the first direction perpendicular to the first direction, and the portion close to the riveted tail is between the cross-sectional outer diameters of the riveted head along the first direction perpendicular to the first direction and the cross-sectional outer diameters of the riveted tail along the first direction perpendicular to the first direction.

[0009] Preferably, the diameter of the riveted head is 4-8 mm, the diameter of the riveted tail is 5-11 mm; the diameter of the riveted waist is 2-7.5 mm; and the height of the riveted piece is 2-10 mm.

[0010] Preferably, the rivet is a solid rivet.

[0011] A riveting structure comprises a material plate and a riveting piece; the material plate is used to be placed on a lower riveting die; the riveting piece is used to be placed in an upper riveting die; when the upper riveting die and the lower riveting die move relative to each other, the riveting piece is riveted into the material plate.

[0012] Preferably, the material plate comprises at least two layers of riveted plates, the at least two layers of the riveted plates are stacked along a first direction, and the lowermost layer of the riveted plates is placed on the lower riveting die.

[0013] Preferably, the hardness of the material plate is at least one level lower than the hardness of the rivet.

[0014] Preferably, a limiting hole is provided on one side of the material plate close to the lower riveting die, and when the rivet is inserted into the material plate, the height of the riveted tail of the rivet outside the material plate is 0.2 to 0.5 mm; the depth of the limiting hole is 0.3 to 1.5 mm; the distance between the hole wall of the limiting hole and the outer wall of the rivet head is 0.5 to 4 mm.

[0015] A riveting die structure comprises a lower riveting die and an upper riveting die arranged opposite to the lower riveting die; the upper riveting die is used to place the riveted parts; the lower riveting die is used to receive the material plate in the riveted structure.

[0016] Preferably, the lower riveting die comprises a lower riveting die body, a riveting and forming portion extending from the lower riveting die body, and a lower die cavity penetrating the lower riveting die body and the riveting and forming portion;

[0017] A limiting hole is provided on one side of the material plate close to the lower riveting die, and the limiting hole matches the riveting forming part of the lower riveting die.

[0018] Preferably, the riveting and forming part is a flat die structure, and the flat die structure includes a first columnar protrusion extending from the lower riveting die body, and the lower riveting die body and the first columnar protrusion penetrate to form the lower die cavity.

[0019] Preferably, when the riveting forming part is a flat die structure, the limiting hole of the material plate is a cylindrical hole, and the depth of the limiting hole is 0.3 to 1.5 mm;

[0020] Among the cross-sectional apertures of the material plate along the first direction perpendicular to the first direction, the cross-sectional aperture close to the riveting forming portion is 5 to 14 mm.

[0021] Preferably, the riveting forming part is a stepped mold structure, which includes a second cylindrical protrusion extending from the lower rivet mold body and a third cylindrical protrusion extending from the second cylindrical protrusion. The lower rivet mold body, the second cylindrical protrusion and the third cylindrical protrusion penetrate to form the lower mold cavity; the outer diameter of the second cylindrical protrusion is greater than the outer diameter of the third cylindrical protrusion.

[0022] Preferably, when the riveting forming part is a stepped mold structure, the limiting hole of the material plate is a stepped hole, and the depth of the limiting hole is 0.3 to 1.5 mm;

[0023] Among the cross-sectional apertures of the material plate along the first direction perpendicular to the first direction, the cross-sectional aperture close to the riveting forming portion is 5 to 14 mm.

[0024] Preferably, the riveting forming part is a slope mold structure, which includes a trapezoidal protrusion extending from the lower rivet mold body, the lower rivet mold body and the trapezoidal protrusion penetrate to form the lower mold cavity, and a surface of the trapezoidal protrusion away from the lower rivet mold body is the upper surface of the trapezoidal protrusion.

[0025] Preferably, when the riveting forming part is a slope mold structure, the limiting hole of the material plate is a truncated cone hole, and the depth of the limiting hole is 0.3 to 1.5 mm;

[0026] Among the cross-sectional apertures of the material plate along the first direction perpendicular to the first direction, the cross-sectional aperture close to the riveting forming portion is 5 to 16 mm.

[0027] A riveting device comprises a riveting gun, the riveting die structure and a riveting pressing mechanism;

[0028] The riveting gun comprises a lower electrode and an upper electrode which are arranged opposite to each other;

[0029] The lower riveting die is installed on the lower electrode, and the lower riveting die is used to place the material plate;

[0030] The upper riveting die is mounted on the upper electrode, and the upper electrode is used to drive the upper riveting die to approach or move away from the lower riveting die to press or loosen the material plate;

[0031] The riveting mechanism is assembled in the upper riveting die and is used to drive the riveting member to rivet the material plate.

[0032] The rivet provided by the embodiment of the utility model is used to penetrate into the material plate, and specifically includes a rivet tail, a rivet waist and a rivet head arranged in sequence along the first direction; the rivet first pierces the material plate during the descending process, and when the riveting is completed, the rivet tail presses on the uppermost plate material of the material plate, the rivet waist penetrates into the material plate, and the rivet head presses on the lowermost plate material of the material plate, so that the rivet tail and the rivet head clamp the part material plate, so that a firm mechanical interlocking structure is formed between the material plates, thereby reducing cracking and improving the quality of self-piercing riveting. Among them, the rivet is a rivet; the material plate can be a two-layer structure, a three-layer structure or a multi-layer structure. The outer diameter of the cross section of the rivet head along the first direction is smaller than the outer diameter of the cross section of the rivet tail along the first direction; among the outer diameters of the cross section of the rivet waist along the first direction, the part close to the rivet head is smaller than the outer diameter of the cross section of the rivet head along the first direction, and the part close to the rivet tail is between the outer diameters of the cross section of the rivet head along the first direction and the outer diameters of the cross section of the rivet tail along the first direction. Such a setting of the riveted waist will form a concave arc area. Under great pressure, the material sheet begins to undergo transverse and longitudinal plastic deformation according to the shape of the riveted waist, squeezes into the concave arc area of ​​the riveted waist, increases the fluidity of the material, and thus forms interlocking. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions of the embodiments of the utility model, the drawings required for use in the description of the embodiments of the utility model will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0034] Figure 1 This is a front view of the riveted structure in one embodiment of the utility model

[0035] Figure 2 This is a first structural diagram of the lower riveting die in one embodiment of the utility model;

[0036] Figure 3 This is a second structural diagram of the lower riveting die in one embodiment of the utility model;

[0037] Figure 4 This is a third structural diagram of the lower riveting die in one embodiment of the utility model;

[0038] Figure 5 This is a front view of a riveting device in one embodiment of the utility model;

[0039] Figure 6 yes Figure 5 The enlarged view of point A in the middle;

[0040] Figure 7It is a step diagram of a method for using a riveting device in one embodiment of the utility model.

[0041] Among them, 1. Riveted parts; 11. Riveted tail; 12. Riveted waist; 13. Riveted head; 2. Material plate; 21. Riveted plate; 22. Limiting hole; 3. Lower riveting die; 31. Lower riveting die body; 32. Riveting forming part; 321. Flat die structure; 322. Step die structure; 323. Slope die structure; 33. Lower die cavity; 4. Upper riveting die; 5. Riveting gun; 51. Lower electrode; 52. Upper electrode; 53. C-shaped body; 54. Support part; 55. Installation part; 6. Riveting mechanism; 61. Nail feeding tube; 62. Power mechanism. DETAILED DESCRIPTION

[0042] In order to make the technical problems, technical solutions and beneficial effects solved by the utility model more clear, the utility model is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the utility model and are not used to limit the utility model.

[0043] In the description of the present invention, it should be understood that the terms "longitudinal", "radial", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships 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 a limitation on the present invention. In the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0044] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed 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 it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0045] The utility model embodiment provides a riveted part 1, referring to Figure 1The rivet 1 comprises a rivet tail 11, a rivet waist 12 and a rivet head 13 arranged in sequence along a first direction; the outer diameter of the cross section of the rivet head 13 along the first direction perpendicular to the first direction is smaller than the outer diameter of the cross section of the rivet tail 11 along the first direction perpendicular to the first direction; among the outer diameters of the cross section of the rivet waist 12 along the first direction perpendicular to the first direction, the portion close to the rivet head 13 is smaller than the outer diameter of the cross section of the rivet head 13 along the first direction perpendicular to the first direction, and the portion close to the rivet tail 11 is between the outer diameters of the cross section of the rivet head 13 along the first direction perpendicular to the first direction and the outer diameters of the cross section of the rivet tail 11 along the first direction perpendicular to the first direction.

[0046] The first direction is the direction from the riveted tail portion 11 to the riveted head portion 13 , that is, the axial direction of the riveted component 1 .

[0047] As an example, the rivet 1 is used to penetrate into the sheet 2, and specifically includes a rivet tail 11, a rivet waist 12 and a rivet head 13 arranged in sequence along the first direction; the rivet 1 first pierces the sheet 2 during the descending process, and when the riveting is completed, the rivet tail 11 presses on the uppermost plate material of the sheet 2, the rivet waist 12 penetrates into the sheet 2, and the rivet head 13 presses on the lowermost plate material of the sheet 2, so that the rivet tail 11 and the rivet head 13 clamp the part sheet 2, so that a firm mechanical interlocking structure is formed between the sheet 2, thereby reducing cracking and improving the quality of self-piercing riveting. Among them, the rivet 1 is a rivet; the sheet 2 can be a two-layer structure, a three-layer structure or a multi-layer structure. The cross-sectional outer diameter of the rivet head 13 along the first direction is smaller than the cross-sectional outer diameter of the rivet tail 11 along the first direction; among the cross-sectional outer diameters of the rivet waist 12 along the first direction, the portion close to the rivet head 13 is smaller than the cross-sectional outer diameter of the rivet head 13 along the first direction, and the portion close to the rivet tail 11 is between the cross-sectional outer diameters of the rivet head 13 along the first direction and the cross-sectional outer diameters of the rivet tail 11 along the first direction. Such arrangement of the rivet waist 12 will form a concave arc-shaped area. Under great pressure, the material sheet 2 begins to undergo transverse and longitudinal plastic deformation according to the shape of the rivet waist 12, squeezes into the concave arc-shaped area of ​​the rivet waist 12, increases the fluidity of the material, and thus forms an interlock.

[0048] In one embodiment, referring to Figure 2 The diameter of the riveted head 13 is 4 to 8 mm, the diameter of the riveted tail 11 is 5 to 11 mm; the diameter of the riveted waist 12 is 2 to 7.5 mm; and the height of the riveted part 1 is 2 to 10 mm.

[0049] As an example, in order to ensure the quality of the riveting point, the height h2 of the rivet 1 is selected according to the thickness h1 of the sheet 2, generally h1≤h2≤h1+1mm. When the sheet 2 is a part on the white body, h1 generally satisfies 2mm≤h1≤9mm, and h2 is 2-10mm. When the material of the sheet 2 is relatively soft, such as aluminum-magnesium alloy and low-carbon steel, h2 is close to h1; when the material of the sheet 2 is relatively hard, such as high-strength steel or hot-formed steel, h2 is close to h1+1mm. The diameter of the rivet 1 can be designed according to demand and should not be too large or too small. If it is too large, a large hole will be punched out on the part, and excessive damage to the part is not conducive to ensuring the strength of the material; if it is too small, the rivet is easy to break or pull off during peeling, and it is not easy to ensure the strength of the connection point. Based on actual design requirements, in order to ensure that the rivet 1 can smoothly penetrate the sheet 2 without yielding, the size of the rivet 1 is limited; the diameter L1 of the rivet head 13 is generally designed to be 4mm≤L1≤8mm, that is, the diameter of the rivet head 13 is 4-8mm, the diameter L2 of the rivet tail 11 is generally designed to be L1+1mm≤L2≤L1+3mm, that is, the diameter of the rivet tail 11 is 5-11mm; the diameter R of the rivet waist 12 is generally designed to be L1-2mm≤R≤L1-0.5mm, that is, the diameter of the rivet waist 12 is 2-7.5mm; the above dimensions can be adjusted according to requirements.

[0050] In one embodiment, referring to Figure 1 , the rivet 1 is a solid rivet.

[0051] As an example, the rivet 1 is a solid rivet, and the rivet 1 is squeezed into the material plate 2 to form an interlock, thereby reducing the deformation of the rivet 1 during the riveting process. In this way, the range of materials that can be riveted by the rivet 1 is greatly expanded, and at the same time, the constraints on the overlap sequence of parts, material thickness, etc. are very low, which can significantly simplify product design and achieve weight reduction and cost reduction.

[0052] The utility model embodiment provides a riveting structure, referring to Figure 1-4 , including a material plate 2 and a rivet part 1; the material plate 2 is used to be placed on the lower riveting die 3; the rivet part 1 is used to be placed in the upper riveting die 4; when the upper riveting die 4 and the lower riveting die 3 move relative to each other, the rivet part 1 is riveted into the material plate 2.

[0053] As an example, the riveting structure includes a sheet 2 and a riveting member 1; the sheet 2 is used to be placed on the lower riveting die 3; the riveting member 1 is used to be placed in the upper riveting die 4; when the upper riveting die 4 and the lower riveting die 3 move relative to each other, the riveting member 1 is riveted into the sheet 2. The riveting member 1 includes a riveting tail 11, a riveting waist 12 and a riveting head 13 arranged in sequence along a first direction; the riveting member 1 first pierces the sheet 2 during the descending process, and when the riveting is completed, the riveting tail 11 is pressed on the uppermost plate material of the sheet 2, the riveting waist 12 is penetrated into the sheet 2, and the riveting head 13 presses the lowermost plate material of the sheet 2, so that the riveting tail 11 and the riveting head 13 clamp the sheet 2, so that a firm mechanical interlocking structure is formed between the sheet 2, thereby reducing cracking and improving the quality of self-piercing riveting. Among them, the riveting member 1 is a rivet. The cross-sectional outer diameter of the rivet head 13 along the first direction is smaller than the cross-sectional outer diameter of the rivet tail 11 along the first direction; among the cross-sectional outer diameters of the rivet waist 12 along the first direction, the portion close to the rivet head 13 is smaller than the cross-sectional outer diameter of the rivet head 13 along the first direction, and the portion close to the rivet tail 11 is between the cross-sectional outer diameters of the rivet head 13 along the first direction and the cross-sectional outer diameters of the rivet tail 11 along the first direction. Such arrangement of the rivet waist 12 will form a concave arc-shaped area. Under great pressure, the material sheet 2 begins to undergo transverse and longitudinal plastic deformation according to the shape of the rivet waist 12, squeezes into the concave arc-shaped area of ​​the rivet waist 12, increases the fluidity of the material, and thus forms an interlock.

[0054] The riveted structure in this example is applied in the field of body-in-white or home appliance connection, which can bring the following obvious benefits: the range of riveted materials is dramatically expanded, and mixed connections of various materials such as low-carbon steel, medium-carbon steel, high-strength steel and hot-formed steel, ordinary aluminum alloy, low-elongation heat-treatment-free cast aluminum alloy, cast magnesium alloy, copper, carbon fiber, etc. can be achieved. The connection constraints are reduced, and the placement order of the riveted parts, material thickness, and total material thickness are widely applicable. For example, on the white body of a car, as long as space permits, almost all overlap combinations can be riveted. For example, the overlap combination of steel + aluminum + steel of GC420 t2.0+AlSi10 t3.0+GC420 t2.0, the existing technologies used for body-in-white connections in the automotive industry are almost exclusive of bolt connections.

[0055] All other options are not feasible, but solid self-piercing rivets can achieve perfect connection. The body design is simplified, and the advantages of weight reduction and cost reduction are huge. In the past, in order to ensure the feasibility of the connection, many sacrifices and compromises had to be made in the body design, such as increasing the lap width, changing the material of the parts, and increasing the thickness of the parts. Due to the powerful connection ability of solid self-piercing rivets, the body will achieve design freedom to a large extent, resulting in a simplified structure and a rapid reduction in weight cost.

[0056] In one embodiment, referring to Figure 1The material plate 2 includes at least two layers of riveted plates 21 , and the at least two layers of riveted plates 21 are stacked along a first direction, and the bottom layer of riveted plates 21 is placed on the lower riveting die 3 .

[0057] As an example, the material sheet 2 includes at least two layers of riveted plates 21, which are stacked along a first direction, i.e., the axial direction of the riveted part 1, and the bottommost riveted plate 21 is placed on the lower riveting mold 3. The material sheet 2 can be a two-layer structure, a three-layer structure or a multi-layer structure.

[0058] In one embodiment, referring to Figure 1 , the hardness of the sheet metal 2 is at least one level lower than the hardness of the riveted part 1.

[0059] As an example, the material of the riveted part 1 can be selected from aluminum alloy, tool steel, alloy steel and spring steel, etc. The hardness of the material plate 2 is at least one level lower than the hardness of the riveted part 1. The hardness of the riveted part 1 is generally greater than the maximum hardness of the material plate 2 by more than 10HRC, so as to avoid deformation of the riveted part 1 during the riveting process.

[0060] The utility model embodiment provides a riveting die structure, referring to Figure 2-4 , including a lower riveting die 3 and an upper riveting die 4 arranged opposite to the lower riveting die 3; the upper riveting die 4 is used to place the riveted part 1; the lower riveting die 3 is used to receive the material plate 2 in the riveted structure.

[0061] As an example, the riveting die structure includes a lower riveting die 3 and an upper riveting die 4, and the upper riveting die 4 is arranged opposite to the lower riveting die 3; the upper riveting die 4 is used to place the riveted part 1; the lower riveting die 3 is used to receive the material plate 2 in the riveting structure; when the upper riveting die 4 and the lower riveting die 3 move relative to each other, the riveted part 1 is riveted into the material plate 2. The riveted part 1 includes a riveting tail 11, a riveting waist 12 and a riveting head 13 arranged in sequence along a first direction; the riveting part 1 first pierces the material plate 2 during the descending process, and when the riveting is completed, the riveting tail 11 is pressed on the uppermost plate material of the material plate 2, the riveting waist 12 is penetrated into the material plate 2, and the riveting head 13 presses the lowermost plate material of the material plate 2, so that the riveting tail 11 and the riveting head 13 clamp the part material plate 2, so that a firm mechanical interlocking structure is formed between the material plate 2, thereby reducing cracking and improving the quality of self-piercing riveting.

[0062] In one embodiment, referring to Figure 1-4 The lower riveting die 3 includes a lower riveting die body 31, a riveting forming part 32 extending from the lower riveting die body 31, and a lower die cavity 33 penetrating the lower riveting die body 31 and the riveting forming part 32; a limiting hole 22 is provided on one side of the material plate 2 close to the lower riveting die 3, and the limiting hole 22 matches the riveting forming part 32 of the lower riveting die 3.

[0063] As an example, the lower riveting die 3 includes a lower riveting die body 31 and a riveting forming part 32. The lower riveting die body 31 serves as the mounting support part of the lower riveting die 3. The riveting forming part 32 extends from the lower riveting die body 31 and is used to place the sheet 2. The lower die cavity 33 that penetrates the lower riveting die body 31 and the riveting forming part 32 is used to discharge the riveting waste of the sheet 2. A limiting hole 22 is provided on the side of the sheet 2 close to the lower riveting die 3. The limiting hole 22 matches the riveting forming part 32 of the lower riveting die 3. In this way, the sheet 2 does not need more material flow or extrusion during riveting, which further improves the riveting forming property and reduces cracking. For sheet 2 of different riveted materials, the height, width and shape of the lower riveting die 3 are different to ensure that the bottom plate material of the sheet 2 can flow fully; the material of the lower riveting die 3 can be selected from alloy steel or tool steel, etc. In order to ensure the service life, the lower riveting die 3 is usually at least one grade higher in hardness than the material of the riveted part 1 to prevent damage to the die.

[0064] In one embodiment, referring to Figure 1 and Figure 2 The riveting and forming part 32 is a flat die structure 321, and the flat die structure 321 includes a first cylindrical protrusion extending from the lower riveting die body 31. The lower riveting die body 31 and the first cylindrical protrusion penetrate to form a lower die cavity 33; the limiting hole 22 of the material plate 2 is a cylindrical hole, and the depth of the limiting hole 22 is 0.3 to 1.5 mm; among the cross-sectional apertures of the material plate 2 along the first direction perpendicular to the first direction, the cross-sectional aperture close to the riveting and forming part 32 is 5 to 14 mm.

[0065] As an example, the riveting forming part 32 is a flat die structure 321, and the flat die structure 321 includes a first cylindrical protrusion extending from the lower riveting die body 31. The lower riveting die body 31 and the first cylindrical protrusion penetrate to form a lower die cavity 33. It has good applicability for the bottom plate material of ordinary stamping aluminum, profiles, cast aluminum, low carbon steel to high-strength steel materials of about 1000MPa. The riveting forming part 32 is a flat die structure 321. In the riveted material plate 2, the side of the riveted tail 11 is a regular circle, and the side of the riveted head 13 is a regular circle and forms a pit. The limiting hole 22 of the material plate 2 is a cylindrical hole, and the depth of the limiting hole 22 is 0.3 to 1.5 mm, that is, the indentation depth h after riveting. Generally, as the thickness of the bottom material of the material plate 2 increases, the h value increases appropriately. For example, if the thickness of the bottom material is t≤2.0mm, it generally satisfies 0.3mm≤h≤0.8mm; if the thickness of the bottom material is t≥2.0mm, it generally satisfies 0.5mm≤h≤1.5mm, but h≤0.5t. When the rivet 1 is inserted into the sheet 2, the height H of the riveted tail 11 of the rivet 1 outside the sheet 2 generally satisfies 0.2mm≤H≤0.5mm. The diameter L1 of the riveted head 13 is generally designed to be 4mm≤L1≤8mm, that is, the diameter of the riveted head 13 is 4-8mm, and the distance between the hole wall of the limiting hole 22 and the outer wall of the riveted head 13 is I value. The I value is closely related to the pressure that the equipment can provide. At present, due to the actual selected driving electric cylinder pressure rated power of 8KN, it is generally required to be 0.5mm≤I≤3mm. Among the cross-sectional apertures of the sheet 2 perpendicular to the first direction, the cross-sectional aperture close to the riveted forming part 32 is equal to L1+2I, that is, 5-14mm. If the I value is too large, when the bottom material of the sheet 2 is made of high-strength steel or above, the pressure is insufficient and the bottom material is not deformed sufficiently, resulting in insufficient interlocking and decreased strength; if the I value is too small, too little bottom material flows into the riveted waist 12, which may also result in insufficient interlocking and decreased strength.

[0066] In one embodiment, referring to Figure 1 and Figure 3 The riveting forming part 32 is a stepped mold structure 322, and the stepped mold structure 322 includes a second cylindrical protrusion extending from the lower riveting mold body 31 and a third cylindrical protrusion extending from the second cylindrical protrusion. The lower riveting mold body 31, the second cylindrical protrusion and the third cylindrical protrusion penetrate to form a lower mold cavity 33; the outer diameter of the second cylindrical protrusion is greater than the outer diameter of the third cylindrical protrusion; the limiting hole 22 of the material plate 2 is a stepped hole, and the depth of the limiting hole 22 is 0.3~1.5mm; among the cross-sectional apertures of the material plate 2 along the first direction perpendicular to the first direction, the cross-sectional aperture close to the riveting forming part 32 is 5~14mm.

[0067] As an example, the riveting forming part 32 uses a stepped mold structure 322. The stepped mold structure 322 includes a second cylindrical protrusion extending from the lower rivet mold body 31 and a third cylindrical protrusion extending from the second cylindrical protrusion. The lower rivet mold body 31, the second cylindrical protrusion and the third cylindrical protrusion penetrate to form a lower mold cavity 33; the outer diameter of the second cylindrical protrusion is larger than the outer diameter of the third cylindrical protrusion. When the equipment pressure is constant, the material flow is smoother because the mold surface is divided into steps. The stepped mold increases the pressure by reducing the contact area to ensure that the high-strength steel flows fully and forms an interlock. For low elongation materials (such as heat-treatment-free aluminum castings). The limiting hole 22 of the material plate 2 is a stepped hole, and the H value is the same as the constraint of the flat mold structure 321. The fillet r value is recommended to be designed as 0mm≤r≤2mm. If the r value is too large, the sharpness of the rivet mold edge will be reduced, which is not conducive to cutting parts. A properly designed smaller r value can avoid stress concentration at the corners of the parts.

[0068] Reduce the risk of cracking and significantly improve the life of the riveting die. When the riveted part 1 is inserted into the sheet 2, the height of the riveted tail 11 of the riveted part 1 outside the sheet 2 is 0.2-0.5mm; the total depth of the indentation depths h3 and h4 after riveting, that is, the depth of the limiting hole 22, is 0.5-1.5mm. The diameter L1 of the riveted head 13 is generally designed to be 4mm≤L1≤8mm, that is, the diameter of the riveted head 13 is 4-8mm; the distance between the hole wall of the limiting hole 22 and the outer wall of the riveted head 13 is the I value, that is, 0.5-3mm, and the I value of the stepped die structure 322 includes I1 and I2. Among the cross-sectional apertures of the sheet 2 perpendicular to the first direction, the cross-sectional aperture close to the riveted forming part 32 is equal to L1+2I, that is, L1+2I1 or L1+2I2, and the value range is 5-14mm. In order to ensure that the riveting force changes as gradually as possible during the process of the bottom material being squeezed into the riveting waist 12, it is generally required that 0.5mm≤I1+I2≤3mm, I2≤I1, 0.5mm≤h3+h4≤1.5mm, h3≈h.

[0069] In one embodiment, referring to Figure 1 and Figure 4 The riveting forming part 32 is a slope mold structure 323, and the slope mold structure 323 includes a trapezoidal protrusion extending from the lower riveting mold body 31. The lower riveting mold body 31 and the trapezoidal protrusion penetrate to form a lower mold cavity 33. A surface of the trapezoidal protrusion away from the lower riveting mold body 31 is the upper surface of the trapezoidal protrusion; the limiting hole 22 of the material plate 2 is a truncated cone hole, and the depth of the limiting hole 22 is 0.3 to 1.5 mm; among the cross-sectional apertures of the material plate 2 along the first direction perpendicular to the first direction, the cross-sectional aperture close to the riveting forming part 32 is 5 to 16 mm.

[0070] As an example, the riveting forming part 32 uses a sloped mold structure 323, and the sloped mold structure 323 includes a trapezoidal protrusion extending from the lower riveting mold body 31. The lower riveting mold body 31 and the trapezoidal protrusion penetrate to form a lower mold cavity 33, and a surface of the trapezoidal protrusion away from the lower riveting mold body 31 is the upper surface of the trapezoidal protrusion. Due to the existence of the slope, the material on the side of the riveting forming part 32 of the heat-treatment-free aluminum casting with poor plasticity is easier to flow into the riveting area, thereby achieving good riveting, reducing the pressure by increasing the contact area, improving the fluidity of the material, guiding the material flow near the fillet of the mold surface to be sufficient, and improving the interlocking value and connection strength. The above three structures solve the problem that high-strength materials and low-plasticity materials are used as the bottom plate of the material plate 2, the solid self-piercing riveting has a small interlocking value and low connection strength, improve the riveting quality, have broad prospects in the automotive industry or other fields, and improve the scope of application of solid self-piercing riveting technology. The limiting hole 22 of the material plate 2 is a truncated cone hole, and the H value and h value are the same as the constraints of the flat mold structure 321, and the fillet r value is the same as the constraint of the stepped mold structure 322. When the rivet 1 is inserted into the material plate 2, the height of the rivet tail 11 of the rivet 1 outside the material plate 2 is 0.2~0.5mm; the depth of the limiting hole 22 is 0.3~1.5mm, that is, the indentation depth h after riveting. The diameter L1 of the riveted head 13 is generally designed to be 4mm≤L1≤8mm, that is, the diameter of the riveted head 13 is 4-8mm; the distance between the hole wall of the limiting hole 22 and the outer wall of the riveted head 13 is the value I, that is, 0.5-4mm, and the value I of the slope mold structure 323 includes I1 and I2. The cross-sectional aperture of the material plate 2 along the cross-sectional aperture perpendicular to the first direction, close to the riveted forming part 32 is equal to L1+2I, that is, L1+2I1 or L1+2I2, and the value range is 5-16mm. The I1 value is the same as the l value of the ordinary flat mold. The L2 value generally satisfies I1+0.2mm≤L2≤I1+1mm. If the I2 value is too small, when riveting high-strength bottom plate materials, the flow of the bottom plate material cannot be well guaranteed; if the I2 value is too large, at the end of the riveting stage, under the condition of a certain driving pressure of the equipment, the pressure bearing surface increases a lot, the average riveting pressure is insufficient, and the bottom plate material cannot be well squeezed into the rivet waist, resulting in insufficient interlocking and reduced strength.

[0071] The rivet 1 in this example is a solid rivet. The rivet 1 is squeezed into the sheet 2 to form an interlock, thereby achieving a riveting method that is completely different from the existing SPR semi-hollow riveting technology route. Compared with the existing SPR riveting technology, the riveting principle is different. The punching and blanking in the riveting process of this scheme are unique to this scheme. The bottom plate material of the sheet 2 is under pressure during the riveting forming process, and the rivet 1 itself does not deform; the rivet 1 is different. The material of the rivet 1 in this scheme is not limited to aluminum alloy. The rivet 1 is a solid structure, and the shape and size are completely different from the SPR rivet; the rivet mold is different. The material, shape and size of the rivet mold in this scheme are completely different from the SPR rivet mold.

[0072] The utility model embodiment provides a riveting device, referring to Figure 1 , Figure 5 and Figure 6 , including a rivet gun 5, a rivet die structure and a riveting pressing mechanism 6; the rivet gun 5 includes a lower electrode 51 and an upper electrode 52 arranged opposite to each other; the lower rivet die 3 is installed on the lower electrode 51, and the lower rivet die 3 is used to place the material plate 2; the upper rivet die 4 is installed on the upper electrode 52, and the upper electrode 52 is used to drive the upper rivet die 4 to approach or move away from the lower rivet die 3 to press or loosen the material plate 2; the riveting pressing mechanism 6 is assembled in the upper rivet die 4, and is used to drive the riveted part 1 to rivet the material plate 2.

[0073] As an example, the riveting equipment includes a riveting gun 5, a riveting die structure and a riveting pressing mechanism 6; the riveting gun 5 includes a lower electrode 51 and an upper electrode 52; the lower electrode 51 and the upper electrode 52 are relatively arranged on the riveting gun 5, the lower riveting die 3 is installed on the lower electrode 51, and the upper riveting die 4 is installed on the upper electrode 52, and a working space is formed between the upper riveting die 4 and the lower riveting die 3. In this example, when in use, the material plate 2 is placed on the lower riveting die 3, and the upper electrode 52 drives the upper riveting die 4 to approach or move away from the lower riveting die 3 to press or loosen the material plate 2; the riveting pressing mechanism 6 is assembled in the upper riveting die 4, and is used to drive the riveting part 1 to rivet the material plate 2. The flat die structure 321 has good applicability for the bottom plate material of ordinary stamping aluminum, profiles, cast aluminum, low carbon steel to high-strength steel materials of about 1000MPa. For high-strength steel materials, such as hot-formed materials, the lower riveting die uses a stepped die structure 322. When the equipment pressure is constant, the stepped die increases the pressure by reducing the contact area to ensure that the high-strength steel fully flows and forms interlocks. For low-elongation materials, such as heat-treatment-free aluminum casting materials, the lower riveting die uses a slope die structure 323. By increasing the contact area, the pressure is reduced, the material fluidity is improved, and the material near the fillet of the die surface is guided to flow fully, thereby increasing the interlocking value and connection strength. The above three structures solve the problem of low interlocking value and low connection strength of solid self-piercing rivets when high-strength materials and low-plasticity materials are used as the bottom plate, thereby improving the riveting quality.

[0074] Among them, the upper riveting die 4 includes an upper riveting die body, and an upper die cavity is arranged in the upper riveting die body; the material plate 2 is placed on the lower riveting die, the upper riveting die body partially overlaps with the longitudinal projection of the lower riveting die body 31, and the upper riveting die body does not overlap with the longitudinal projection of the riveting forming part 32, and the riveting mechanism 6 is assembled in the upper die cavity and moves along the longitudinal direction of the upper die cavity to facilitate riveting the material plate 2. The riveting gun 5 includes a C-shaped body 53, a support portion 54 extending from one end of the C-shaped body 53, and a mounting portion 55 extending from the other end of the C-shaped body 53, and the support portion 54 and the mounting portion 55 are arranged oppositely to form a riveting work space; the lower electrode 51 is fixed on the support portion 54, and a mounting groove is arranged in the mounting portion 55 that passes through from top to bottom, and the upper electrode 52 is assembled in the mounting groove through a slider adapted to the mounting groove, which can facilitate the adjustment of the position of the upper electrode 52, thereby adapting to the riveting work of materials of various thicknesses. The riveting mechanism 6 includes a nail feeding tube 61 and a power mechanism 62; the nail feeding tube 61 is arranged in the upper die cavity, and a riveting piece 1 is arranged in the nail feeding tube 61; the power mechanism 62 is connected to the nail feeding tube 61, and is used to drive the riveting piece 1 in the nail feeding tube 61 to rivet the material plate 2; specifically, the material plate 2 is placed on the lower riveting die 3, and the power mechanism 62 controls the upper riveting die 5 to move downward through the upper electrode 52 to press the material plate 2, and then the power mechanism 62 provides pressure to the nail feeding tube 61 in the upper die cavity to drive the riveting piece 1 The sheet 2 is punched out, and the material at the bottom of the riveted part 1 is separated from the parent material. The waste material punched out falls through the lower die cavity 33. The top size of the riveted part 1 is relatively large, and the topmost riveted plate 21 of the sheet 2 is completely compacted. Under great pressure, the bottommost riveted plate 21 of the sheet 2 begins to undergo lateral and longitudinal plastic deformation according to the shape of the lower riveting die 3, and squeezes into the smaller waist of the riveted part 1, thereby forming an interlocking. After the material is formed, the power mechanism 62 controls the upper riveting die 4 to move upward through the upper electrode 52, and the riveting is successful.

[0075] Reference Figure 5-7In this example, the lower riveting die 3 and the upper riveting die 4 are installed on the riveting gun 5, the riveted part 1 is installed in the nail feeding tube 61, the riveting gun 5 is installed on a fixed support or a robot, and the material plate 2 is placed on the lower riveting die 3; the power mechanism 62 is used to drive the upper riveting die 4 to move and provide pressure to the nail feeding tube 61, and the seven steps of preparation, pressing, nailing, punching, blanking, forming, and leaving are completed in sequence, thereby realizing riveting; specifically, in the preparation stage, the riveting plates 21 of each layer of the material plate 2 are stacked on the lower riveting die 3, the upper riveting die 4 is separated from the material plate 2, and the riveted part 1 can be manually clamped or automatically fed by a machine. There is an integrated nail feeding tube 61, ready for riveting; in the pressing stage, the servo electric cylinder drives the upper electrode 52 to move vertically downward, driving the upper riveting die 4 installed on the upper electrode 52 to descend, and the upper and lower riveting dies press the material plate 2; in the nailing stage, the riveted part 1 is sent out from the nail feeding tube 61 through a conveying guide system such as a blow nail or a lead screw, pressing the top riveted plate 21 of the material plate 2; in the punching stage, the riveted part 1 is under the pressure of the upper electrode 52, and the edge of the riveted part 1 cuts the parts and starts to punch the material plate 2; in the blanking stage, the material plate 2 material at the bottom of the riveted part 1 is separated from the parent material under the pressure of the riveted part 1 to form waste. Under the action of gravity and vacuum suction, the waste falls into a special waste collection box through the lower die cavity 33; in the forming stage, the pressure of the upper and lower riveting dies increases to completely compact the material plate 2. The upper riveting die 4 has a large contact area with the riveted part 1, and the average pressure is small. Due to the design of the boss structure, the lower riveting die 3 has a small contact area with the riveting plate 21 of the lowest layer of the material sheet 2, and the average pressure is very large. Under the great pressure, the riveting plate 21 of the lowest layer of the material sheet 2 begins to undergo transverse and longitudinal plastic deformation according to the shape of the lower riveting die 3, and squeezes into the smaller riveting waist 12 of the riveted part 1, thereby forming an interlock; in the leaving stage, after the material is formed, the servo electric cylinder drives the upper electrode 52 upward, driving the upper and lower dies to separate, take out the parts, and the riveting is completed.

[0076] The riveting equipment of this scheme is suitable for mixed connection of various materials such as steel, aluminum alloy, magnesium alloy, carbon fiber, etc. This scheme drives the solid riveting part 1 to punch out the material plate 2 through the riveting equipment. After the punching is completed, the lower riveting die 3 installed on the equipment squeezes the bottom layer of material of the material plate 2, causing it to undergo plastic deformation and flow into the riveting waist 12, forming an interlocking, thereby achieving connection. Compared with the most commonly used SPR semi-hollow riveting on the current steel-aluminum hybrid body, it has obvious advantages. The range of riveted materials is greatly expanded. At the same time, the constraints on the overlap sequence of the material plate 2 and the thickness of the material plate 2 are very low, which can significantly simplify the product design to achieve weight reduction and cost reduction. Therefore, it has broad application prospects in the automotive and home appliance industries. When used on white bodies or home appliances, the rivet point structure formed has good consistency, uniformity and beauty. The riveted tail 11 fits tightly against the top side of the sheet 2, slightly higher than or completely flush with the top side of the sheet 2, and the bottom material of the sheet 2 is pressed into the riveted waist 12 to form a limiting hole 22. The shape of the limiting hole 22 varies depending on the structure of the selected riveting forming part 32.

[0077] The embodiments described above are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention, and should be included in the protection scope of the present invention.

Claims

1. A riveted part, characterized in that: It includes a riveted tail portion, a riveted waist portion and a riveted head portion which are sequentially arranged along a first direction; The outer diameter of the cross section of the rivet head along the direction perpendicular to the first direction is smaller than the outer diameter of the cross section of the rivet tail along the direction perpendicular to the first direction; Among the cross-sectional outer diameters of the riveted waist along the first direction perpendicular to the first direction, the portion close to the riveted head is smaller than the cross-sectional outer diameter of the riveted head along the first direction perpendicular to the first direction, and the portion close to the riveted tail is between the cross-sectional outer diameters of the riveted head along the first direction perpendicular to the first direction and the cross-sectional outer diameters of the riveted tail along the first direction perpendicular to the first direction.

2. The riveted part according to claim 1, characterized in that: The diameter of the riveted head is 4-8 mm, the diameter of the riveted tail is 5-11 mm; the diameter of the riveted waist is 2-7.5 mm; and the height of the riveted piece is 2-10 mm.

3. The riveted part according to claim 1, characterized in that: The rivet is a solid rivet.

4. A riveted structure, characterized in that: It comprises a material plate and the riveted part according to any one of claims 1 to 3; the material plate is used to be placed on a lower riveting die; the riveted part is used to be placed in an upper riveting die; when the upper riveting die and the lower riveting die move relative to each other, the riveted part is riveted into the material plate.

5. The riveted structure according to claim 4, characterized in that: The material plate includes at least two layers of riveted plates, and the at least two layers of the riveted plates are stacked along a first direction, and the lowermost layer of the riveted plates is placed on the lower riveting die.

6. The riveted structure according to claim 4, characterized in that: The hardness of the material plate is at least one level lower than the hardness of the rivet.

7. The riveted structure according to claim 4, characterized in that: A limiting hole is provided on one side of the material plate close to the lower riveting die. When the rivet is inserted into the material plate, the height of the riveted tail of the rivet outside the material plate is 0.2 to 0.5 mm; the depth of the limiting hole is 0.3 to 1.5 mm; the distance between the hole wall of the limiting hole and the outer wall of the rivet head is 0.5 to 4 mm.

8. A riveting die structure, characterized in that: It comprises a lower riveting die and an upper riveting die arranged opposite to the lower riveting die; the upper riveting die is used to place the riveted part described in any one of claims 1-3; the lower riveting die is used to receive the material plate in the riveted structure described in any one of claims 4-7.

9. The riveting die structure according to claim 8, characterized in that: The lower riveting die comprises a lower riveting die body, a riveting forming part extending from the lower riveting die body, and a lower die cavity penetrating the lower riveting die body and the riveting forming part; A limiting hole is provided on one side of the material plate close to the lower riveting die, and the limiting hole matches the riveting forming part of the lower riveting die.

10. The riveting die structure according to claim 9, characterized in that: The riveting forming part is a flat die structure, and the flat die structure includes a first columnar protrusion extending from the lower riveting die body, and the lower riveting die body and the first columnar protrusion penetrate to form the lower die cavity.

11. The riveting die structure according to claim 10, characterized in that: When the riveting forming part is a flat die structure, the limiting hole of the material plate is a cylindrical hole, and the depth of the limiting hole is 0.3 to 1.5 mm; Among the cross-sectional apertures of the material plate along the first direction perpendicular to the first direction, the cross-sectional aperture close to the riveting forming portion is 5 to 14 mm.

12. The riveting die structure according to claim 9, characterized in that: The riveting forming part is a stepped mold structure, which includes a second cylindrical protrusion extending from the lower rivet mold body and a third cylindrical protrusion extending from the second cylindrical protrusion. The lower rivet mold body, the second cylindrical protrusion and the third cylindrical protrusion penetrate to form the lower mold cavity; the outer diameter of the second cylindrical protrusion is greater than the outer diameter of the third cylindrical protrusion.

13. The riveting die structure according to claim 12, characterized in that: When the riveting forming part is a stepped die structure, the limiting hole of the material plate is a stepped hole, and the depth of the limiting hole is 0.5 to 1.5 mm; Among the cross-sectional apertures of the material plate along the first direction perpendicular to the first direction, the cross-sectional aperture close to the riveting forming portion is 5 to 14 mm.

14. The riveting die structure according to claim 9, characterized in that: The riveting forming part is a slope mold structure, which includes a trapezoidal protrusion extending from the lower rivet mold body. The lower rivet mold body and the trapezoidal protrusion penetrate to form the lower mold cavity, and a surface of the trapezoidal protrusion away from the lower rivet mold body is the upper surface of the trapezoidal protrusion.

15. The riveting die structure according to claim 14, characterized in that: When the riveting forming part is a slope mold structure, the limiting hole of the material plate is a truncated cone hole, and the depth of the limiting hole is 0.3 to 1.5 mm; Among the cross-sectional apertures of the material plate along the first direction perpendicular to the first direction, the cross-sectional aperture close to the riveting forming portion is 5 to 16 mm.

16. A riveting device, characterized in that: It comprises a riveting gun, a riveting die structure and a riveting pressing mechanism as described in any one of claims 8 to 15; The riveting gun comprises a lower electrode and an upper electrode which are arranged opposite to each other; The lower riveting die is installed on the lower electrode, and the lower riveting die is used to place the material plate; The upper riveting die is mounted on the upper electrode, and the upper electrode is used to drive the upper riveting die to approach or move away from the lower riveting die to press or loosen the material plate; The riveting mechanism is assembled in the upper riveting die and is used to drive the riveting member to rivet the material plate.

Images