Fastener, fastening assembly and pressing rivet die

Abstract

The invention discloses a fastener, a fastening assembly and a pressure riveting die, the fastener comprises a body and a boss, and the body is provided with a first surface used for supporting a metal plate. The boss protrudes out of the first face, the size of the boss is smaller than that of the body, the boss is provided with the first flower teeth connected with the first face, and due to the fact that the first flower teeth are provided with the multiple tooth parts, sheet metal materials flow into gaps of the adjacent tooth parts, and the torsion resistance capacity when the fastener is connected with the sheet metal can be improved. And if the diameter of the first flower tooth is gradually reduced in the direction towards the first surface, the first flower tooth and the first surface or other surfaces form an inverted taper ear-shaped flower tooth groove, so that the connection reliability and stability are improved, and the tensile capacity of the product can be improved. The boss is further provided with the first groove which is concave inwards, compared with a drum type, the boss is not prone to slipping off, the material containing space of a product can be increased, the connecting strength of materials such as light alloy with low shear capacity after riveting is improved, and the tensile capacity of the product is improved.

Description

Technical Field

[0001] The invention relates to the field of connecting pieces, and in particular to a fastener, a fastening assembly and a riveting die. Background Art

[0002] Fasteners are a type of mechanical parts used for fastening and connection and are widely used. Various fasteners can be seen on various machinery, equipment, vehicles, ships, railways, bridges, buildings, structures, tools, instruments, meters and supplies. It involves many fields such as materials science, mechanical engineering, and manufacturing processes. The lightweight trend in the automotive industry has prompted the innovation of body fastening connection technology. As a new type of fastener product, the rivet nut is a fastener used on thin plates or sheet metal. It has changed the traditional way of installing parts on thin plates, improved the installation efficiency and connection reliability, and met the needs of many fields such as home appliances, aviation manufacturing and automobile lightweighting. The working principle of the rivet nut is based on the cold deformation characteristics of the material. The nut's unique embossed teeth and groove design are pressed into the interior of the thin plate material at one time through pressure to form a stable connection point. With the rapid development of modern industry, especially in the aerospace, automobile manufacturing, electronic and electrical industries, the demand for fasteners is growing. As an advanced connection technology, the market demand for rivet nuts continues to expand. However, the existing rivet nuts have the problems of insufficient pull-off and poor torsion resistance, which makes them difficult to use. Summary of the invention

[0003] The purpose of the present invention is to overcome the above-mentioned defects or problems existing in the background technology and to provide a fastener, a fastening assembly and a riveting die.

[0004] To achieve the above objectives, the present invention and its preferred embodiments adopt the following technical solutions, but the embodiments are not limited to the following solutions:

[0005] Solution 1: A fastener comprising:

[0006] A body having a first surface;

[0007] A boss protrudes from the first surface, and the size of the boss is smaller than the size of the body. The boss is provided with a first tooth connected to the first surface, the diameter of the first tooth gradually decreases in the direction toward the first surface and / or the boss is also provided with a first groove recessed inwardly.

[0008] Option 2, based on Option 1, the boss includes a first boss and a second boss, the first boss protrudes from the first surface, the first boss is provided with the first flower tooth, and the diameter of the first flower tooth gradually decreases in the direction toward the first surface; the second boss protrudes from the top surface of the first boss, the size of the second boss is smaller than the size of the first boss, and the second boss is provided with a first groove which is recessed inward and extends to the top surface of the first boss.

[0009] Solution three, based on solution two, the first boss is further provided with a second flower tooth, the second flower tooth extends in a vertical direction, and the bottom end of the second flower tooth is connected to the top end of the first groove.

[0010] Solution 4: Based on Solution 3, the top angle of the first flower tooth and / or the top angle of the second flower tooth is 85-95°.

[0011] Solution five, based on solution three, the first boss is further provided with a second groove, the second groove opens to the top surface of the first boss and is connected to the first groove.

[0012] Option six, based on Option one, further includes a reinforcing rib, wherein the reinforcing rib protrudes from the first surface and extends along the radial direction of the main body to connect with the first flower tooth, and the height of the reinforcing rib is lower than the height of the first flower tooth.

[0013] Solution seven, based on solution six, the width of the reinforcing rib gradually decreases or increases along the direction approaching the first surface 11).

[0014] Option 8, a fastening assembly, comprising sheet metals riveted together and a fastener as described in any one of Options 1 to 7, wherein the sheet metal is against the first surface, the material of the sheet metal is engaged with the first tooth, or the material of the sheet metal is engaged with the first tooth and the first groove.

[0015] Solution nine, based on solution eight, the sheet metal also rests against the top surface of the boss.

[0016] Solution 10, a riveting die, which is suitable for riveting a sheet metal and a fastener as described in any one of Solution 1 to Solution 7 together, the sheet metal is provided with a through hole, the boss is interference fit with the through hole, and the boss is provided with a positioning hole;

[0017] The riveting die comprises an upper die, a lower die, a positioning pin and an elastic member;

[0018] The upper die is suitable for accommodating the fastener, and the boss faces the lower die;

[0019] The lower die is suitable for supporting the sheet metal;

[0020] The positioning pin is suitable for passing through the through hole and being positioned and matched with the positioning hole, and the positioning pin is suitable for supporting the top surface of the boss and having a first gap between the positioning pin and the top surface of the boss;

[0021] The two ends of the elastic member act on the positioning pin and the lower mold respectively, and are suitable for applying a force toward the fastener to the positioning pin;

[0022] The upper die is adapted to move toward the lower die so that the boss presses the sheet metal so that the material of the sheet metal flows into the first tooth and the first gap, or the material of the sheet metal flows into the first tooth, the first gap and the first groove.

[0023] From the above description of the present invention and its preferred embodiments, it can be seen that, compared with the prior art, the technical solution of the present invention and its preferred embodiments have the following beneficial effects due to the adoption of the following technical means:

[0024] 1. In solution 1 and its preferred embodiment, a fastener comprises a body and a boss,

[0025] The main body is provided with a first surface for supporting the sheet metal.

[0026] The boss protrudes from the first surface, and the size of the boss is smaller than the size of the body. The boss is provided with a first tooth. Since the first tooth has a plurality of teeth, the sheet metal material flows into the gap between the adjacent teeth, which can improve the torsion resistance of the fastener when connected to the sheet metal. If the diameter of the first tooth gradually decreases in the direction toward the first surface to form an inverted cone ear-shaped tooth groove with the first surface or other surfaces, it is beneficial to guide the flow of materials, especially the extrusion deformation of non-metallic materials and metal materials with high elastic modulus (such as aluminum alloy), increase the connection reliability and stability, and because the sheet metal material is limited by the first tooth and the first surface after flowing in, it can improve the tensile strength of the product.

[0027] In the prior art ( Fig.18 ) The side wall of the boss bulges outwards and is in a drum shape (caused by the plastic deformation of the carbon steel during the cold forging and extrusion process), and the sheet metal is easy to slip along the drum-shaped side wall after riveting. In this solution, the boss is also provided with a first groove that is concave inwards, which is not easy to slip compared to the drum shape, and can increase the material storage space of the product, improve the connection strength of materials with low shear resistance such as lightweight alloys after riveting, and improve the tensile strength of the product.

[0028] If the fastener has both of the above conditions, the tensile performance is significantly improved.

[0029] 2. In the second scheme and its preferred embodiment, the boss includes a first boss and a second boss, the first boss protrudes from the first surface, the first boss is provided with a first tooth, the diameter of the first tooth gradually decreases in the direction toward the first surface; the second boss protrudes from the top surface of the first boss, the size of the second boss is smaller than the size of the first boss, the second boss is provided with a first groove concave inwardly, the first groove and the top surface or other surface of the first boss form an inwardly concave inverted cone ear groove, which is used to increase the material capacity of the product during riveting. The first boss and the second boss are stepped so that the sheet metal material can flow into the first boss first and then into the second boss to ensure uniform material flow.

[0030] 3. In scheme three and its preferred embodiment, the first boss is further provided with a second tooth, which extends in the vertical direction. The bottom end of the second tooth is connected to the top end of the first groove, thereby improving the torsion resistance after riveting, maximizing the use of the space of the fastener, and playing a multiple anti-twist role.

[0031] 4. Scheme 4 and its preferred embodiments: The top angle of the first tooth is 85-95°. Specifically, if this top angle is designed to be too large, the sheet metal will easily slip and the torsion resistance will be weakened; if this top angle is designed to be too small, the tooth will easily collapse, resulting in a sudden drop in torsion resistance, especially when materials such as light alloys are easy to slip, and high-strength plates and ultra-high-strength plates are easy to collapse the tooth. Only by adopting this special angle design can the torsion resistance after riveting be taken into account (ensuring the largest possible contact area between the side of the tooth and the sheet metal) and the compressive resistance during riveting be taken into account (preventing the tooth from collapsing, resulting in a sudden drop in torsion resistance). The top angle of the second tooth is 85-95°, which can take into account the torsion resistance after riveting (ensuring the largest possible contact area between the side of the tooth and the sheet metal) and the compressive resistance during riveting be taken into account (preventing the tooth from collapsing, resulting in a sudden drop in torsion resistance).

[0032] 5. Option 5 and its preferred embodiment: The first boss is also provided with a second groove, which opens at the top surface of the first boss and is connected to the bottom end of the first groove, so as to further increase the material storage space of the product and enhance the connection strength.

[0033] 6. Scheme 6 and its preferred embodiments: the reinforcing rib protrudes from the first surface, improves the torsion resistance after riveting, maximizes the use of the nut space, and plays a multiple anti-torsion role. The shear resistance of materials such as light alloys is relatively low, so the multiple anti-torsion design is used to meet the high-strength and high-stability connection requirements of special materials. The reinforcing rib extends along the radial direction of the body to connect with the first tooth, and the height of the reinforcing rib is lower than the height of the first tooth, so that when the diameter of the first tooth gradually decreases in the direction toward the first surface, it forms an inverted cone ear-shaped tooth groove with the first tooth.

[0034] 7. In the seventh solution and its preferred embodiment: the width of the reinforcing rib gradually decreases or increases along the direction close to the first surface, and the width of the reinforcing rib gradually decreases along the direction close to the first surface, which can improve the anti-slip performance. The width of the anti-rotation teeth gradually increases along the direction close to the first surface, which can facilitate the flow of the sheet metal material toward the first surface.

[0035] 8. Option 8 and its preferred embodiment: a fastening assembly, including a sheet metal and the above-mentioned fastener riveted together as a whole, the sheet metal is against the first surface, the material of the sheet metal is engaged with the first tooth, or the material of the sheet metal is engaged with the first tooth and the first groove, having the beneficial effects brought by the above-mentioned fastener.

[0036] 9. In scheme nine and its preferred embodiment, the sheet metal also rests against the top surface of the boss to increase the pull-off performance.

[0037] 10. In the tenth scheme and its preferred embodiment, a riveting die is suitable for riveting the sheet metal and the above-mentioned fastener into one body, the sheet metal is provided with a through hole, the boss is interference fit with the through hole, and the boss is provided with a positioning hole; the riveting die comprises an upper die, a lower die, a positioning pin and an elastic member. The upper die is suitable for accommodating the fastener and making the boss face the lower die; the lower die is suitable for supporting the sheet metal; the positioning pin is suitable for passing through the through hole and positioning with the positioning hole, the positioning pin is suitable for supporting the top surface of the boss, and there is a first gap between the positioning pin and the top surface of the boss; the two ends of the elastic member act on the positioning pin and the lower die respectively, and are suitable for applying a force toward the fastener to the positioning pin; the upper die is suitable for moving toward the lower die so that the boss squeezes the sheet metal, so that the material of the sheet metal flows into the first tooth and the first gap, or the material of the sheet metal flows into the first tooth, the first gap and the first groove, so as to solve the problem that the fastener is difficult to position when the boss and the through hole are interference fit to increase the connection strength between the two after riveting, and eliminate the appearance defects such as burrs and sheet metal stamping after riveting. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0039] Figure 1 is a three-dimensional diagram of the fastener in the first embodiment;

[0040] Figure 2 is a top view of the fastener in Example 1;

[0041] Figure 3 for Figure 2 Section view along the AA section line;

[0042] Figure 4for Figure 3 Enlarged view of the marked area;

[0043] Figure 5 Schematic diagram of the vertex angles of the first flower tooth and the second flower tooth in Example 1;

[0044] Figure 6 This is a schematic diagram of the structure of the riveting die before riveting in Example 1;

[0045] Figure 7 This is a structural schematic diagram of the riveting die in the first embodiment;

[0046] Figure 8 This is a structural schematic diagram of the riveting die in Example 1 after riveting is completed;

[0047] Fig. 9 for Figure 8 Enlarged view of the marked area;

[0048] Fig.10 is a three-dimensional diagram of the fastener in the second embodiment;

[0049] Fig.11 It is a schematic diagram of the structure of the fastener in the second embodiment;

[0050] Fig.12 is a three-dimensional diagram of the fastener in Example 3;

[0051] Fig.13 It is a structural schematic diagram of the fastener in the third embodiment;

[0052] Fig.14 is a three-dimensional diagram of the fastener in the fourth embodiment;

[0053] Fig.15 is a schematic diagram of the structure of the fastener in the fourth embodiment;

[0054] Fig.16 is a three-dimensional diagram of the fastener in Embodiment 5;

[0055] Fig.17 It is a structural schematic diagram of the fastener in the fifth embodiment;

[0056] Fig.18 It is a schematic diagram of a drum-shaped boss in the prior art.

[0057] Description of main reference numerals:

[0058] Body 1; first surface 11; boss 2; positioning hole 21; first boss 22; first flower tooth 221; second groove 222; second boss 23; second flower tooth 231; first groove 232; reinforcing rib 3; upper die 4; accommodating groove 41; lower die 5; base 51; first lower die inner hole 511; second lower die inner hole 512; limiting surface 5121; screw plug 52; positioning pin 6; first introduction cone angle 61; first step 62; second introduction cone angle 63; second step 64; third step 65; fourth step 66; elastic member 7; first gap 8; sheet metal 9; through hole 91; DETAILED DESCRIPTION

[0059] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are preferred embodiments of the present invention and should not be regarded as excluding other embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0060] In the claims, description and the above-mentioned drawings of the present invention, unless otherwise clearly defined, the use of terms such as "first", "second" or "third" etc. are for distinguishing different objects rather than for describing a specific order.

[0061] In the claims, specification and the above-mentioned drawings of the present invention, unless otherwise explicitly defined, directional words, such as the terms "center", "lateral", "longitudinal", "horizontal", "vertical", "top", "bottom", "inside", "outside", "up", "down", "front", "back", "left", "right", "clockwise", "counterclockwise", etc., indicating directions or positional relationships are based on the directions and 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 direction or be constructed and operated in a specific direction, and therefore cannot be understood as limiting the specific protection scope of the present invention.

[0062] In the claims, specification and the above drawings of the present invention, unless otherwise clearly defined, if the term "fixed connection" or "fixed connection" is used, it should be understood in a broad sense, that is, any connection method without a displacement relationship and relative rotation relationship between the two, that is to say, including non-detachable fixed connection, detachable fixed connection, integrated connection and fixed connection through other devices or elements.

[0063] In the claims, description and drawings of the present invention, if the terms "include", "have" and their variations are used, they are intended to mean "including but not limited to".

[0064] Embodiment 1:

[0065] refer to Figure 1-Figure 9 A fastener includes a body 1, a boss 2 and a reinforcing rib 3. The fastener can be a bolt or a nut. This embodiment takes a nut as an example.

[0066] refer to Figure 1 In this embodiment, the body 1 is a cylinder with an outer diameter of 19.85-20.15 mm and a thickness of 7.6 mm-7.8 mm. In other embodiments, the shape of the body 1 is not limited and may also be a hexagon, an octagon, a polygon, etc. The body 1 is provided with a first surface 11, which is the top surface of the body 1 and is suitable for supporting the sheet metal 9.

[0067] refer to Figure 1 The boss 2 protrudes from the first surface 11, and the size of the boss 2 is smaller than that of the body 1. The boss 2 is provided with a positioning hole 21, which penetrates the fastener in the vertical direction and is in the form of a threaded hole to realize threaded connection with other parts, and its specification is M12*1.5.

[0068] refer to Figure 1 The boss 2 includes a first boss 22 and a second boss 23. The first boss 22 protrudes from the first surface 11, Figure 4 The first boss 22 is provided with a first tooth 221 and a second groove 222. The first tooth 221 is connected to the first surface 11, and the diameter of the first tooth 221 gradually decreases in the direction toward the first surface 11. The tensile performance after riveting is further improved. Specifically, in this embodiment, the first tooth 221 has an outer diameter of 16.8-17.2 mm, a height of 0.6-0.9 mm, a top angle of 85-95°, and an angle of 3°-8° with the first surface 11. The second groove 222 opens on the top surface of the first boss 22. The depth of the second groove 222 close to the axis of the boss 2 is the deepest, and the depth gradually decreases along the direction away from the axis of the boss 2 and close to the top surface of the first boss 22.

[0069] refer to Figure 4The second boss 23 protrudes from the top surface of the first boss 22, and the size of the second boss 23 is smaller than that of the first boss 22. The second boss 23 is provided with a second flower tooth 231 and a first groove 232 that is recessed inwardly, wherein the line connecting the top and bottom ends of the first groove 232 is defined as the first line segment, and the inward recess means that the bottom of the first groove 232 is located on the side of the first line segment close to the central axis of the boss 2, and the first groove 232 is roughly an inward concave fillet of R2.6-R2.8mm. The first groove 232 extends to the top surface of the first boss 22 and forms an inward concave inverted cone ear groove with the top surface of the first boss 22, which is used to increase the material capacity of the product during riveting, and the bottom end of the first groove 232 is connected to the second groove 222 to further increase the material capacity. The second flower tooth 231 extends in the vertical direction (its diameter does not change in the vertical direction), and its outer diameter is 15.8-15.95mm and its height is 1.5-1.7mm. The bottom end of the second tooth 231 is connected to the top end of the first groove 232. In order to take into account the torsion resistance after riveting, to ensure as large a contact area between the side of the tooth and the sheet metal 9 as possible, and the compressive resistance during riveting, to prevent the tooth from being crushed, resulting in a sudden decrease in torsion resistance, refer to Figure 5 The vertex angle of the first flower tooth 221 is 85-95°, and the vertex angle of the second flower tooth 231 is 85-95°.

[0070] refer to Figure 1 , the reinforcing rib 3 protrudes from the first surface 11 and extends along the radial direction of the body 1 to connect with the first flower tooth 221. The height of the reinforcing rib 3 is lower than the height of the first flower tooth 221, so it can form an inverted cone ear-shaped flower tooth groove with the first flower tooth 221. In this embodiment, the width of the reinforcing rib 3 along the direction close to the first surface 11 remains unchanged. However, in other embodiments, preferably, the width of the reinforcing rib 3 gradually decreases or increases along the direction close to the first surface 11. In this embodiment, 8 reinforcing ribs 3 with a width of 1.10-1.30 mm and a height of 0.30-0.50 mm are evenly distributed on the first surface 11. The number of reinforcing ribs 3 is not limited, and can also be 4, 6, etc.

[0071] The above-mentioned fasteners can be riveted together with the sheet metal 9 by a riveting die to form a fastening assembly.

[0072] Specifically, refer to Figure 7-Figure 9 , a riveting die, suitable for riveting sheet metal 9 and navigation tree fasteners into one.

[0073] refer to Figure 7 The sheet metal 9 is provided with a through hole 91 , and the boss 2 is interference fit with the through hole 91 . In this embodiment, the second boss 23 is first interference fit with the through hole 91 .

[0074] The riveting die comprises an upper die 4 , a lower die 5 , a positioning pin 6 and an elastic member 7 .

[0075] refer to Figure 7 The upper die 4 is suitable for accommodating fasteners, and the boss 2 faces the lower die 5. Specifically, the upper die 4 is provided with a receiving groove 41. The inner diameter of the receiving groove 41 should be adapted to the body 1. The inner diameter of the receiving groove 41 is 0.05-0.20mm larger than the outer diameter of the body 1 to ensure that the nut can be easily inserted. The depth of the receiving groove 41 should be 0.05-0.3mm smaller than the thickness of the body 1 to ensure that the nut will protrude from the upper die 4 after being inserted. Otherwise, the nut will be blocked by the upper die 4, and the reinforcing rib 3 and the first flower tooth 221 cannot be completely riveted into the sheet metal 9.

[0076] The lower die 5 is suitable for supporting the sheet metal 9. The lower die 5 includes a base 51 and a screw plug 52. The base 51 is provided with a first lower die 5 inner hole and a second lower die 5 inner hole. The second lower die 5 inner hole is provided with a limited position surface 5121. The first lower die 5 inner hole is used for the positioning pin 6 to extend. The inner hole of the first lower die 5 is 9.95-10.05 mm deep and has an inner diameter of 15.73-15.76 mm. The inner hole of the first lower die 5 is connected to the inner hole of the second lower die 5 with an inner diameter of 20.00-20.03 mm and a length of 50-60 mm. The bottom of the base 51 is an M24*3.0 internal thread with a length of 20-21 mm. The screw plug 52 is provided with an inner hexagon wrench with a width of 6.02-6.14 mm and a depth of 3.95-4.05, and an M24*3 external thread of the screw plug 52 with a length of 11.90-12.10 mm.

[0077] The positioning pin 6 is suitable for passing through the through hole 91 and positioning with the positioning hole 21. The positioning pin 6 is suitable for supporting the top surface of the boss 2 and has a first gap 8 with the top surface of the boss 2. The first introduction cone angle 61 of the positioning pin 6 is 135°-145°, which plays the role of introducing the nut. The first introduction cone angle 61 is downwardly a first step 62 with a height of 5.04-5.10mm and an outer diameter of 10.50-10.53mm. The outer diameter of the first step 62 is adapted to the positioning hole 21 of the nut and should be smaller than the positioning hole 21 of the nut. The first step 62 is connected to the second step 64 through the second introduction cone angle 63 (the first gap 8 is formed between the second introduction cone angle 63 and the top surface of the boss 2). The outer diameter of the second step 64 is adapted to the through hole 91 of the sheet metal 9 and should be smaller than the through hole 91 of the sheet metal 9. In this embodiment, the outer diameter of the second step 64 is 15.69-15.71mm and the height is 14.91-14.95mm. Connected downwardly to the second step 64 is a third step 65 with a height of 9.9-1.1 mm and an outer diameter of 19.96-19.99 mm, the outer diameter of the third step 65 matches the inner hole of the first lower die 5 and should be 0.05-0.10 mm smaller than the inner diameter of the inner hole of the first lower die 5. Connected downwardly to the third step 65 is a fourth step 66 with a height of 4.95-5.05 mm and an outer diameter of 4.97-5.00 mm.

[0078] The two ends of the elastic member 7 act on the positioning pin 6 and the screw plug 52 of the lower die 5 respectively, and are suitable for applying a force toward the fastener to the positioning pin 6;

[0079] The upper die 4 is adapted to move toward the lower die 5 so that the boss 2 squeezes the sheet metal 9 , so that the material of the sheet metal 9 and the material flowing into the sheet metal 9 flow into the first tooth 221 , the first gap 8 and the first groove 232 .

[0080] Specifically, the positioning pin 6 passes through the inner holes of the first lower mold 5 and the second lower mold 5, and the third step 65 abuts against the limiting surface 5121 of the inner hole of the second lower mold 5. The elastic member 7 is sleeved on the fourth step 66, and the other end of the elastic member 7 abuts against the screw plug 52. The expansion and contraction amount of the elastic member 7 can be adjusted through the screw plug 52 to fix the positioning pin 6 on the lower mold 5.

[0081] The schematic diagram of riveting before riveting is as follows Figure 6 As shown, the boss 2 of the nut abuts against the second lead-in cone 63, and the first step 62 passes through the positioning hole 21 of the nut to play a positioning role. The upper die 4 abuts against the end of the nut, and the through hole 91 of the sheet metal 9 is inserted into the second step 64.

[0082] The riveting process is as follows Figure 7 As shown, the upper die 4 presses the nut downward, and the nut is pressed into the sheet metal 9 along the positioning pin 6. The positioning pin 6 is moved toward the screw plug 52 by the pressure of the nut until the first surface 11 on the body 1 is flush with the end surface of the sheet metal 9, and the riveting is completed. Figure 8 After the riveting is completed, the positioning pin 6 will rebound to the initial position due to the action of the elastic member 7, and continue the next riveting. This solves the problem of the difficulty in nut positioning.

[0083] like Fig. 9 As shown, after riveting, the sheet metal 9 is pressed against the first surface 11, and the sheet metal 9 material is engaged with the first flower tooth 221, the second flower tooth 231, the first groove 232, the second groove 222 and the reinforcing rib 3, and pressed against the top surface of the boss 2. At this point, the friction force generated by the interference fit between the first flower tooth 221, the second flower tooth 231 and the sheet metal 9, the first groove 232, and the first flower tooth 221 form a four-layer anti-pull-off structure, and the tensile performance is significantly improved.

[0084] The first flower tooth 221, the second flower tooth 231, and the reinforcing rib 3 form a triple anti-torsion structure after riveting, and the anti-torsion performance is significantly improved.

[0085] Embodiment 2:

[0086] refer to Fig.10 , Fig.11 , which is different from the first embodiment, in this embodiment, there is no second groove 222 .

[0087] Embodiment three:

[0088] refer to Fig.12 , Fig.13, which is different from the second embodiment, this embodiment does not have a reinforcing rib 3.

[0089] Embodiment 4:

[0090] refer to Fig.14 , Fig.15 Different from the second embodiment, this embodiment does not have the second flower tooth 231, and its first groove 232 can have a larger arrangement space.

[0091] Embodiment five:

[0092] refer to Fig.16 , Fig.17 , which is different from the fourth embodiment, this embodiment does not have a reinforcing rib 3.

[0093] Embodiment 2 to Embodiment 5 can also be riveted together with the sheet metal 9 by the above-mentioned riveting die.

[0094] The description of the above specification and embodiments is used to explain the protection scope of the present invention, but does not constitute a limitation on the protection scope of the present invention. Through the enlightenment of the present invention or the above embodiments, ordinary technicians in this field can obtain modifications, equivalent substitutions or other improvements to the embodiments of the present invention or part of the technical features thereof through logical analysis, reasoning or limited experiments, which should be included in the protection scope of the present invention.

Claims

1. A fastener, characterized in that: include A body (1) having a first surface (11); A boss (2) protrudes from the first surface (11), and the size of the boss (2) is smaller than the size of the body (1), and the boss (2) is provided with a first tooth (221), the diameter of the first tooth (221) gradually decreases in the direction toward the first surface (11) and / or the boss (2) is further provided with a first groove (232) recessed inwardly.

2. A fastener according to claim 1, characterized in that: The boss (2) comprises a first boss (22) and a second boss (23); the first boss (22) protrudes from the first surface (11); the first boss (22) is provided with the first tooth (221); the diameter of the first tooth (221) gradually decreases in the direction toward the first surface (11); the second boss (23) protrudes from the top surface of the first boss (22); the size of the second boss (23) is smaller than the size of the first boss (22); the second boss (23) is provided with a first groove (232) recessed inwardly.

3. A fastener according to claim 2, characterized in that: The first boss (22) is further provided with a second tooth (231), the second tooth (231) extending in a vertical direction, the bottom end of the second tooth (231) being connected to the top end of the first groove (232).

4. A fastener according to claim 3, characterized in that: The top angle of the first flower tooth (221) and / or the top angle of the second flower tooth (231) is 85-95°.

5. A fastener according to claim 3, characterized in that: The first boss (22) is also provided with a second groove (222), the second groove (222) opening at the top surface of the first boss (22) and communicating with the bottom end of the first groove (232).

6. A fastener according to claim 1, characterized in that: It also includes a reinforcing rib (3), which protrudes from the first surface (11) and extends along the radial direction of the body (1) to connect with the first flower tooth (221), and the height of the reinforcing rib (3) is lower than the height of the first flower tooth (221).

7. A fastener according to claim 6, characterized in that: The width of the reinforcing rib (3) gradually decreases or increases along the direction approaching the first surface (11).

8. A fastening assembly, characterized in that: It comprises a sheet metal (9) riveted together and a fastener as described in any one of claims 1 to 7, wherein the sheet metal (9) is against the first surface (11), the material of the sheet metal (9) is engaged with the first tooth (221), or the material of the sheet metal (9) is engaged with the first tooth (221) and the first groove (232).

9. A fastening assembly according to claim 8, characterized in that: The sheet metal (9) also abuts against the top surface of the boss (2).

10. A riveting die, characterized in that: It is suitable for riveting a sheet metal (9) and a fastener as claimed in any one of claims 1 to 7 into one, the sheet metal (9) is provided with a through hole (91), the boss (2) is interference fit with the through hole (91), and the boss (2) is provided with a positioning hole (21); The riveting die comprises an upper die (4), a lower die (5), a positioning pin (6) and an elastic member (7); The upper mold (4) is suitable for accommodating the fastener and making the boss (2) face the lower mold (5); The lower mold (5) is suitable for supporting the sheet metal (9); The positioning pin (6) is suitable for passing through the through hole (91) and being positioned and matched with the positioning hole (21); the positioning pin (6) is suitable for supporting the top surface of the boss (2) and having a first gap (8) between the positioning pin (6) and the top surface of the boss (2); The two ends of the elastic member (7) act on the positioning pin (6) and the lower mold (5) respectively, and are suitable for applying a force toward the fastener to the positioning pin (6); The upper die (4) is suitable for moving toward the lower die (5) so that the boss (2) squeezes the sheet metal (9) so that the material of the sheet metal (9) flows into the first tooth (221) and the first gap (8), or the material of the sheet metal (9) flows into the first tooth (221), the first gap (8) and the first groove (232).

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