Fastener, riveting assembly and machining method and punch of fastener

Abstract

The invention discloses a fastener, a riveting assembly, a machining method of the fastener and a punch. The fastener comprises a body, a convex navel and a convex ring. The body is provided with a supporting surface; and the convex navel protrudes out of the supporting surface and is provided with a flanging hole or a flanging groove, so that the convex navel yields and deforms under the pressure action of a punch until the convex navel is bent to buckle the metal plate, the metal plate is clamped by the convex navel and the supporting surface, and the pull-off resistance is improved. The at least two convex rings are arranged in a concentric circle mode, the convex rings surround the convex navel and protrude out of the supporting face, on one hand, the concentric convex rings increase the contact area of the fastener and the metal plate, and therefore the anti-rotation torque is increased; on the other hand, after riveting, the annular convex ring is embedded into the metal plate, so that the metal plate can be prevented from sliding outwards in the radial direction, the metal plate is prevented from being disengaged, a supporting face is changed into multiple circles inside and outside, the contact area of the metal plate and the body is increased, larger axial clamping force can be provided, and it is guaranteed that the metal plate or the body does not yield or deform; and the risk of axial clamping force attenuation is reduced. The fastener is reliable in riveting performance, low in cost and suitable for dissimilar metal connection.

Description

Technical Field

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

[0002] Fasteners are a type of mechanical parts used for fastening and connection and are extremely widely used. They are widely used in various machinery, equipment, vehicles, ships, railways, construction and other industries. With the development of the automobile industry and technological progress, as well as the country's increased requirements for energy conservation and emission reduction, the extensive application of new materials and new processes, and the increasing intensity of market competition, new requirements have been put forward for the simplification of automotive fastener processing technology, the lightweighting of parts, the diversification of uses, and the optimization of costs. Therefore, riveted nuts are widely used and promoted as a product to replace the original welding connection method. The existing welding nuts are composed of a rim, a welding foot, a screw hole, and a body. During the actual connection application during the welding process, the energy consumption is large, the pollution is serious, and it is difficult to achieve connection with dissimilar metals or non-metals. 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 riveting assembly, a fastener processing method and a punch.

[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 support surface;

[0007] A convex navel, which protrudes from the supporting surface and is provided with a flanging hole or a flanging groove;

[0008] The convex rings have at least two and are arranged in concentric circles. The convex rings surround the convex navel and protrude from the supporting surface.

[0009] Solution 2: Based on Solution 1, the cross-sectional size of the convex ring gradually increases or decreases in the direction approaching the supporting surface.

[0010] Solution three, based on solution one, further includes at least one anti-rotation groove, which opens on the supporting surface and divides the convex ring into several sections.

[0011] Solution 4: Based on Solution 3, the cross-sectional size of the anti-rotation groove gradually increases or decreases in the direction approaching the supporting surface.

[0012] Solution five, based on Solution three, the anti-rotation groove extends along the radial direction of the convex ring and extends to the side wall of the fastener.

[0013] Solution six, based on Solution one, further includes an anti-rotation rib, which protrudes from the support surface, extends along the radial direction of the convex ring and is connected to at least one of the convex rings.

[0014] Solution seven, based on Solution six, the anti-rotation rib connects the adjacent convex rings and / or connects the convex rings and the convex navel.

[0015] Option 8, a riveting assembly, comprising sheet metal and a fastener as described in any one of Option 1 to Option 7, wherein the umbilicus is suitable for deforming to clamp the sheet metal together with the supporting surface, and the convex ring is suitable for piercing the sheet metal.

[0016] Solution 9, a method for processing a fastener, which is suitable for processing a fastener as described in any one of Solution 1 to Solution 7, comprising the following steps:

[0017] The blank is shaped by a cold heading die so that a first groove is formed on the blank and a first piece is obtained;

[0018] Punching the first piece with a cold heading die to deepen the groove depth of the first groove of the first piece and form a second groove on the other side to obtain a second piece;

[0019] The middle part of the second piece is made to protrude radially by a cold heading die to form a first protrusion, and a third piece is obtained;

[0020] Using a cold heading die, the third piece is used to shape the first protrusion to obtain a rim, and the first groove is shaped to form a convex navel, thereby obtaining a fourth piece;

[0021] The rim of the fourth piece is formed into a body and a convex ring by a cold heading die, and the first groove is further deepened to obtain a fifth piece;

[0022] The first groove and the second groove of the fifth piece are penetrated by a cold heading die.

[0023] Solution 10. A punch suitable for forming a fastener as described in Solution 6 or Solution 7, comprising:

[0024] A protrusion, which is suitable for forming the flanging hole or the flanging groove;

[0025] A first annular groove, which surrounds the protrusion and is suitable for forming the umbilicus;

[0026] at least two second annular grooves arranged in concentric circles, the second annular grooves surround the first annular groove, and the second annular grooves are suitable for forming the convex ring,

[0027] an anti-rotation groove extending in the radial direction of the second annular groove and communicating with at least one of the second annular grooves and suitable for forming the anti-rotation rib;

[0028] The exhaust hole has one end opening at the groove bottom of the anti-rotation groove and the other end opening at the side wall of the punch.

[0029] 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:

[0030] 1. In scheme 1 and its preferred embodiment, a fastener includes a body, a convex navel and a convex ring.

[0031] The main body is provided with a support surface; the convex navel protrudes from the support surface, and is provided with a flanging hole or a flanging groove, so that under the pressure of the punch, the convex navel yields and deforms until it bends and buckles the sheet metal, so that the convex navel and the support surface clamp the sheet metal, thereby improving the performance of anti-pull-off. There are at least two convex rings arranged in concentric circles, which surround the convex navel and protrude from the support surface. On the one hand, the concentric convex rings increase the contact area between the fastener and the sheet metal, thereby increasing the anti-rotation torque; on the other hand, after riveting, this annular convex ring is embedded in the sheet metal, which can limit the radial outward sliding of the sheet metal, thereby preventing the sheet metal from falling out, and making the support surface also become multiple circles inside and outside, thereby increasing the contact area between the sheet metal and the main body, and can provide a greater axial clamping force, while ensuring that the sheet metal or the main body does not yield and deform, and reducing the risk of axial clamping force attenuation. The fastener has reliable riveting performance, low cost, and is suitable for connecting dissimilar metals.

[0032] 2. In the second scheme and its preferred embodiment, the cross-sectional size of the convex ring gradually increases in the direction close to the support surface, which is conducive to piercing into the sheet metal and better forming through the mold. When the cross-sectional size of the convex ring gradually decreases in the direction close to the support surface, the anti-pull-off performance of the fastener and the sheet metal along the axial direction can be improved.

[0033] 3. Scheme 3 and its preferred embodiment further include at least one anti-rotation groove, which opens on the supporting surface to improve the anti-rotation performance between the fastener and the sheet metal after riveting. The anti-rotation groove divides the convex ring into several sections to facilitate the forming of the structure.

[0034] 4. In the fourth scheme and its preferred embodiment, the cross-sectional dimensions of the anti-rotation groove gradually increase in the direction close to the support surface. During the riveting process, the sheet metal yields and deforms under the extrusion force. The "wide at the top and narrow at the bottom" structure is conducive to the material being squeezed into this concave anti-rotation groove. In this anti-rotation groove, the sheet metal and the side wall of the anti-rotation groove are interlocked to prevent the fastener from rotating relative to the sheet metal, and it is better to be formed by the mold. When the cross-sectional dimensions of the anti-rotation groove gradually decrease in the direction close to the support surface, the anti-pull-off performance of the fastener and the sheet metal along the axial direction can be improved.

[0035] 5. In scheme five and its preferred embodiment, the anti-rotation groove extends along the radial direction of the convex ring and extends to the side wall of the fastener to increase the anti-rotation effect.

[0036] 6. Option 6 and its preferred embodiments further include anti-rotation ribs, which protrude from the support surface, extend along the radial direction of the convex ring and are connected to at least one convex ring. Combined with the cold heading process, cavity channels for exhaust and oil drainage are designed to ensure that multiple circles of convex rings can be smoothly formed. At the same time, when the oil and gas are exhausted, the metal material fills the mold cavity and becomes an anti-rotation rib higher than the support surface (that is, the anti-rotation rib is formed by utilizing the mold oil groove), thereby playing an anti-rotation role.

[0037] 7. In scheme seven and its preferred embodiments, the anti-rotation ribs connect adjacent convex rings and / or connect the convex rings and the convex navels, thereby improving the anti-rotation effect during the cold heading process.

[0038] 8. In scheme eight and its preferred embodiment, a riveted assembly includes a sheet metal and the above-mentioned fastener, the convex navel is suitable for deforming to clamp the sheet metal together with the supporting surface, and the convex ring is suitable for piercing the sheet metal, and has the beneficial effects brought by the above-mentioned fastener.

[0039] 9. Scheme 9 and its preferred embodiment, a method for processing a fastener, which is suitable for processing the above fastener, comprises the following steps: shaping the blank through a cold heading die to form a first groove on the blank and obtain a first piece; inserting the first piece through a cold heading die to deepen the groove depth of the first groove of the first piece and form a second groove on the other side to obtain a second piece; making the middle part of the second piece protrude radially through a cold heading die to form a first convex portion and obtain a third piece; shaping the first convex portion of the third piece through a cold heading die to obtain a rim, and shaping the first groove to form a convex navel to obtain a fourth piece; forming a body and a convex ring on the rim of the fourth piece through a cold heading die, and further deepening the first groove to obtain a fifth piece; and connecting the first groove and the second groove of the fifth piece through a cold heading die. The molding method is simple; and in the process of connecting the first groove and the second groove to form the body and the convex ring, the molding is gradually performed through multiple cold headings, thereby reducing the stress concentration caused by one-time molding and the phenomenon of easy fracture.

[0040] 10. Option 10, a punch, which is suitable for forming the above-mentioned fastener, comprises a protrusion, a first annular groove, a second annular groove, an anti-rotation groove, and an exhaust hole, wherein the protrusion is suitable for forming a flanging hole or a flanging groove; the first annular groove surrounds the outside of the protrusion, which is suitable for forming a convex navel; at least two second annular grooves arranged in concentric circles, the second annular groove surrounds the outside of the first annular groove, the second annular groove is suitable for forming a convex ring, the anti-rotation groove extends along the radial direction of the second annular groove and is connected with at least one second annular groove; the exhaust hole, one end of which opens at the bottom of the anti-rotation groove, and the other end of which opens at the side wall of the punch, exhaust is carried out through the exhaust hole to ensure that multiple circles of convex rings can be smoothly formed. At the same time, when the oil and gas are exhausted, the metal material fills the mold cavity to become an anti-rotation rib higher than the support surface (that is, the anti-rotation rib is formed by utilizing the mold oil groove), thereby playing an anti-rotation role. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] 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.

[0042] Figure 1 is a three-dimensional diagram of the fastener in the first embodiment;

[0043] Figure 2 is a top view of the fastener in the first embodiment;

[0044] Figure 3 for Figure 2 Sectional view of the AA section plane;

[0045] Figure 4 It is a schematic diagram of the fastener and the sheet metal after riveting in the first embodiment;

[0046] Figure 5 It is a schematic diagram of the structure of the blank in Example 1;

[0047] Figure 6 It is a structural schematic diagram of the first item in Example 1;

[0048] Figure 7 It is a structural schematic diagram of the second piece in the first embodiment;

[0049] Figure 8 It is a schematic structural diagram of the third element in the first embodiment;

[0050] Fig. 9 It is a schematic structural diagram of the fourth item in the first embodiment;

[0051] Fig.10 It is a schematic diagram of the structure of the fifth item in the first embodiment;

[0052] Fig.11 It is a structural schematic diagram of the fastener in the first embodiment;

[0053] Fig.12 is a three-dimensional diagram of the punch in Example 1;

[0054] Fig.13 is a top view of the punch in Example 1;

[0055] Fig.14 is a schematic diagram of the structure of the punch in the first embodiment, Fig.13 Section view along the section line shown.

[0056] Description of main reference numerals:

[0057] Main body 1; supporting surface 11; convex navel 2; flanging hole 21; convex ring 3; anti-rotation groove 4; anti-rotation rib 5; sheet metal 6; blank 7; first piece 81; first groove 811; second piece 82; second groove 821; third piece 83; first convex portion 831; fourth piece 84; rim 841; fifth piece 85; first surface 91; protrusion 92; first annular groove 93; second annular groove 94; anti-rotation groove 95; exhaust hole 96. DETAILED DESCRIPTION

[0058] 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.

[0059] 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.

[0060] 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.

[0061] 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.

[0062] 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".

[0063] refer to Figure 1-Figure 3 A fastener includes a body 1, a convex navel 2, a convex ring 3, an anti-rotation groove 4, and an anti-rotation rib 5.

[0064] The body 1 is provided with a support surface 11. In this embodiment, the body 1 may be circular, or may be a quadrangular structure, a hexagonal structure, an octagonal structure, etc. In this embodiment, the body 1 is circular, with a specification of M8 and a diameter of 16-24 mm.

[0065] The convex navel 2 protrudes from the supporting surface 11. In this embodiment, the convex navel 2 is coaxially arranged with the body 1. The convex navel 2 is annular, with a diameter of 11-13 mm and a height of 2 mm-5 mm. The main function of the convex navel 2 is to buckle the sheet metal 6 with the flange during riveting to generate a resistance force (i.e., a pull-off force) to resist pulling off; in this embodiment, the convex navel 2 is provided with a flange hole 21, and the flange hole 21 passes through the fastener, and the mold extends into the flange hole 21 so that the hole wall of the flange hole 21 is deformed to make the convex navel 2 flange. In this embodiment, the flange hole 21 passes through the convex navel 2 and is a threaded hole. The flange hole 21 is coaxially arranged with the body 1, and can also be eccentrically arranged under special application conditions. For example, when this threaded hole is used as a positioning function part, when the outer wall of the body 1 plays a positioning or limiting function, the threaded hole can be eccentrically arranged with the body 1. In other embodiments, the convex navel 2 can be provided with a flange groove (not through) to make the convex navel 2 flange.

[0066] The convex ring 3 has at least two and is arranged in concentric circles. The convex ring 3 surrounds the convex navel 2 and protrudes from the support surface 11 to divide the support surface 11 into a coaxially arranged multi-circle support plane. After riveting, this support plane is completely in contact with the sheet metal 6 surface. The design of multiple inner and outer circles increases the contact area between the sheet metal 6 and the body 1, and can provide a larger axial clamping force, while ensuring that the sheet metal 6 or the body 1 does not yield and deform, and reducing the risk of axial clamping force attenuation; the height of the convex ring 3 is 0.3-0.5mm, and the cross-sectional size of the convex ring 3 is close to the support surface. 11 gradually increases or decreases. Preferably, the cross-sectional size of the convex ring 3 gradually increases in the direction close to the supporting surface 11, and is a "narrow at the top and wide at the bottom" structure. During the riveting process, this "narrow at the top and wide at the bottom" structure is conducive to piercing the sheet metal 6; on the one hand, this structure increases the contact area between the fastener and the sheet metal 6, thereby increasing the anti-rotation torque; on the other hand, after riveting, the convex ring 3 is embedded in the sheet metal 6, which can limit the radial outward sliding of the sheet metal 6, thereby preventing the sheet metal 6 from falling out, increasing the pull-out force after riveting, and improving the connection strength. In the opposite case, the anti-slip performance in the axial direction can be increased. In this embodiment, the convex ring 3 has two.

[0067] The number of anti-rotation grooves 4 is at least one. In this embodiment, there are eight anti-rotation grooves 4, grouped in pairs, and evenly arranged among groups. The anti-rotation grooves 4 open on the support surface 11, the bottom surface of the anti-rotation grooves 4 is lower than the support surface 11, and the convex ring 3 is divided into several segments. The anti-rotation grooves 4 extend along the radial direction of the convex ring 3, penetrate through the two convex rings 3 and extend to the side wall of the fastener. The depth of the anti-rotation grooves 4 is 0.1 - 0.4 mm. The cross-sectional dimension of the anti-rotation grooves 4 gradually increases or gradually decreases along the direction close to the support surface 11. In this embodiment, the cross-sectional dimension of the anti-rotation grooves 4 gradually increases along the direction close to the support surface 11. Preferably, the cross-section of the anti-rotation grooves 4 in the axial direction has a "wide upper and narrow lower" structure. During the riveting process, the sheet metal 6 yields and deforms under the extrusion force, and the "wide upper and narrow lower" structure is conducive to the material being extruded into the anti-rotation grooves 4. Inside the anti-rotation grooves 4, the sheet metal 6 forms an interlock with the side walls of the anti-rotation grooves 4 to prevent the nut from rotating relative to the sheet metal 6. In the opposite case, the anti-disengagement performance in the axial direction can be increased.

[0068] The number of anti-rotation ribs 5 is four and evenly arranged. Specifically, they are located between adjacent groups of anti-rotation grooves 4. The anti-rotation ribs 5 protrude from the support surface 11, extend along the radial direction of the convex ring 3 and are connected to the convex ring 3. Preferably, the anti-rotation ribs 5 connect adjacent convex rings 3, and connect the innermost convex ring 3 and the convex navel 2. During the riveting process, the anti-rotation ribs 5 penetrate into the sheet metal 6 to play an anti-rotation role. On the other hand, during the cold heading forming process, before the metal material fills the cavity, this cavity channel plays a role in discharging oil and gas to ensure that the convex ring 3 can be formed smoothly. Among them, the anti-rotation ribs 5 extending along the radial direction of the convex ring 3 includes that the extending direction of the anti-rotation ribs 5 is parallel to a radial direction of the convex ring 3 or has a certain included angle, as long as the anti-rotation effect can be achieved.

[0069] This fastener can be either a nut or a bolt. In this embodiment, a nut is taken as an example.

[0070] The processing method of this fastener includes the following steps:

[0071] Refer to Figure 5-Figure 11 , and the blank is shaped by a cold heading die so that a first groove 811 is formed on the blank 7 and the first piece 81 is obtained; the blank is cylindrical.

[0072] The first piece 81 is jacked by a cold heading die so that the groove depth of the first groove 811 of the first piece 81 is deepened, and a second groove 821 is formed on the other side, and the second piece 82 is obtained.

[0073] The middle part of the second piece 82 is made to protrude radially by a cold heading die to form a first convex part 831, and the third piece 83 is obtained. The third piece 83 is generally in the shape of a "middle" character as a whole.

[0074] The third piece 83 is shaped by a cold heading die to shape the first protrusion 831 to obtain the rim 841 , and the first groove 811 is shaped to form the umbilicus 2 , thereby obtaining the fourth piece 84 , wherein the umbilicus 2 protrudes from the rim 841 .

[0075] The rim 841 of the fourth piece 84 is formed into a body 1 and a convex ring 3 by a cold heading die to form a riveting feature, and the first groove 811 is further deepened to obtain a fifth piece 85; Figure 12-14 Specifically, the cold heading die includes a punch, which includes a first surface 91, a protrusion 92, a first annular groove 93, a second annular groove 94, an anti-rotation groove 95 and an exhaust hole 96. The protrusion 92 is suitable for forming a flanging hole or a flanging groove. In this example, the protrusion 92 is used to deepen the first groove 811; the first annular groove 93 surrounds the outside of the protrusion 92, which is suitable for forming a convex navel 2, at least two second annular grooves 94 are arranged in concentric circles, the second annular groove 94 surrounds the outside of the first annular groove 93, and the second annular groove 94 is suitable for forming a convex ring 3, the anti-rotation groove 95 extends along the radial direction of the second annular groove 94, and the anti-rotation groove is connected to at least one second annular groove 94. Preferably, in this embodiment, the anti-rotation groove 95 connects the adjacent second annular grooves 94, and connects the innermost second annular groove 94 and the first annular groove 93. The oil and gas at the convex navel 2 and each convex ring 3 can be discharged from the anti-rotation groove 95, and the die structure is simpler. One end of the exhaust hole 96 opens at the bottom of the anti-rotation groove 95, and the other end opens at the side wall of the punch to achieve the function of exhausting oil and gas. In this embodiment, the top of the protrusion 92 is flush with the first surface 91, and the first annular groove 93, the second annular groove 94, and the anti-rotation groove 95 are all opened at the first surface 91.

[0076] The first groove 811 and the second groove 821 of the fifth member 85 are connected by a cold heading die, so that the first groove 811 and the second groove 821 are connected to form the flange hole 21. The forming method is simple, so the corresponding die is also relatively simple; and in the process of connecting the first groove 811 and the second groove 821 to form the body 1 and the convex ring 3, the forming is gradually performed by multiple cold headings, so as to reduce the stress concentration caused by one-time forming and the phenomenon of easy fracture.

[0077] Compared with the prior art, this embodiment has the following beneficial effects:

[0078] In an exemplary embodiment, a fastener includes a body 1 , a convex navel 2 and a convex ring 3 .

[0079] The body 1 is provided with a support surface 11; the convex navel 2 protrudes from the support surface 11, and is provided with a flanging hole 21 or a flanging groove, so that the convex navel 2 yields and deforms under the pressure of the punch until it bends and buckles the sheet metal 6, so that the convex navel 2 and the support surface 11 clamp the sheet metal 6, and improve the performance of anti-pull-off. There are at least two convex rings 3 and they are arranged in concentric circles. The convex rings 3 surround the convex navel 2 and protrude from the support surface 11. On the one hand, the concentric convex rings 3 increase the contact area between the fastener and the sheet metal 6, thereby increasing the anti-rotation torque; on the other hand, after riveting, this annular convex ring 3 is embedded in the sheet metal 6, which can limit the radial outward sliding of the sheet metal 6, thereby preventing the sheet metal 6 from coming out. Compared with the design of a U-shaped and inward-inclined annular groove to achieve the above effect, in the scheme of the annular groove, the sheet metal 6 is easy to come out of the annular groove, the pull-off force after riveting is small, the connection strength is low, and the riveting effect is better in the form of the convex ring 3. The supporting surface 11 is also changed to multiple inner and outer circles. Compared with the prior art which has only the outermost supporting surface 11, this solution increases the contact area between the sheet metal 6 and the body 1, can provide a larger axial clamping force, and ensure that the sheet metal 6 or the body 1 does not yield and deform, and reduces the risk of axial clamping force attenuation. The fastener has reliable riveting performance, low cost, and is suitable for connecting dissimilar metals.

[0080] In an exemplary embodiment, the cross-sectional size of the protruding ring 3 gradually increases in the direction close to the supporting surface 11, which is conducive to piercing into the sheet metal 6 and better forming through the mold. When the cross-sectional size of the protruding ring 3 gradually decreases in the direction close to the supporting surface 11, the anti-pull-off performance of the fastener and the sheet metal 6 in the axial direction can be improved.

[0081] In an exemplary embodiment, it also includes at least one anti-rotation groove 4, which opens on the support surface 11 to improve the anti-rotation performance between the fastener and the sheet metal 6 after riveting. The anti-rotation groove 4 divides the convex ring 3 into several sections to facilitate the forming of the structure.

[0082] In an exemplary embodiment, the cross-sectional dimensions of the anti-rotation groove 4 gradually increase in the direction close to the support surface 11. During the riveting process, the sheet metal 6 yields and deforms under the extrusion force. The "wide at the top and narrow at the bottom" structure facilitates the material to be squeezed into the concave anti-rotation groove 4. In the anti-rotation groove 4, the sheet metal 6 and the side wall of the anti-rotation groove 4 are interlocked to prevent the fastener from rotating relative to the sheet metal 6 and better pass through the mold. When the cross-sectional dimensions of the anti-rotation groove 4 gradually decrease in the direction close to the support surface 11, the anti-pull-off performance of the fastener and the sheet metal 6 along the axial direction can be improved.

[0083] In an exemplary embodiment, the anti-rotation groove 4 extends along the radial direction of the protruding ring 3 and extends to the side wall of the fastener to enhance the anti-rotation effect.

[0084] In an exemplary embodiment, an anti-rotation rib 5 is also included. The anti-rotation rib 5 protrudes from the support surface 11, extends along the radial direction of the convex ring 3 and is connected to the convex ring 3. In combination with the cold heading process, a cavity channel for exhaust and oil drainage is designed to ensure that multiple circles of convex rings 3 can be smoothly formed. At the same time, when the oil and gas are exhausted, the metal material fills the mold cavity and becomes an anti-rotation rib higher than the support surface 11 (that is, the anti-rotation rib is formed by the mold oil groove), which plays an anti-rotation role. Compared with the method of setting the convex teeth in the annular groove to achieve the anti-rotation effect, the molding process is simpler and the mold life is longer.

[0085] In an exemplary embodiment, the anti-rotation ribs 5 connect adjacent convex rings 3 and / or connect the convex rings 3 and the convex navel 2 to enhance the anti-rotation effect during the cold heading process.

[0086] In an exemplary embodiment, a punch is suitable for forming the above-mentioned fastener, which includes a protrusion 92, a first annular groove 93, a second annular groove 94, an anti-rotation groove 95, and an exhaust hole 96. The protrusion 92 is suitable for forming a flanging hole 21 or a flanging groove; the first annular groove 93 surrounds the outside of the protrusion 92, which is suitable for forming a convex navel 2; at least two second annular grooves 94 are arranged in concentric circles, the second annular groove 94 surrounds the outside of the first annular groove 93, and the second annular groove 94 is suitable for forming a convex ring 3. The anti-rotation groove 95 extends along the radial direction of the second annular groove 94 and is connected with at least one second annular groove 94, and is suitable for forming an anti-rotation rib 5; the exhaust hole 96, one end of which opens at the bottom of the anti-rotation groove 95, and the other end of which opens at the side wall of the punch, and exhaust is performed through the exhaust hole 96 to ensure that multiple circles of convex rings 3 can be smoothly formed. At the same time, when the oil and gas are exhausted, the metal material fills the mold cavity to become an anti-rotation rib 5 higher than the support surface 11 (that is, the anti-rotation rib 5 is formed by using the mold oil groove), which plays an anti-rotation role. Compared with the method of setting the convex teeth in the annular groove to achieve the anti-rotation effect, the molding process is simpler and the mold life is longer.

[0087] Embodiment 2

[0088] refer to Figure 4 The riveting assembly includes a sheet metal 6 and the above-mentioned fastener, the umbilicus 2 is suitable for deforming to clamp the sheet metal 6 together with the supporting surface 11, the convex ring 3 and the anti-rotation rib 5 are suitable for piercing the sheet metal 6, and the sheet metal 6 is suitable for filling the anti-rotation groove 4.

[0089] Before riveting, the hole sleeve on the sheet metal 6 is set on the convex navel 2. During the riveting process, the punch extends into the flange hole 21 or the flange groove. Under the pressure of the punch, the convex navel 2 yields and deforms until it bends and buckles the sheet metal 6. Continue to apply pressure, the punch and the bent and deformed convex navel 2 squeeze the sheet metal 6 to deform, the convex ring 3 and the anti-rotation rib 5 penetrate into the sheet metal 6, and at the same time, the sheet metal 6 material is also squeezed into the anti-rotation groove 4. Finally, the convex navel 2 is flanged and fastened to the sheet metal 6. The convex navel 2 can ensure that the nut does not peel off from the sheet metal 6 under a certain axial load; at the same time, the convex ring 3 is embedded in the sheet metal 6, which can limit the radial sliding of the sheet metal 6 to the outside, thereby preventing the sheet metal 6 from coming out, increasing the pull-off force after riveting, and improving the connection strength. The plane of the sheet metal 6 is completely in contact with the support surface 11, and the interlocking structure formed by the anti-rotation groove 4, the side wall of the anti-rotation groove 4, the anti-rotation rib 5 and the sheet metal 6 can ensure that the nut does not rotate relative to the sheet metal 6 under a large torque. This design is also applicable to self-clinching bolts.

[0090] 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) provided with a support surface (11); A convex navel (2) protruding from the supporting surface (11) and provided with a flanging hole (21) or a flanging groove; The convex rings (3) have at least two and are arranged in a concentric circle. The convex rings (3) surround the convex navel (2) and protrude from the supporting surface (11).

2. A fastener according to claim 1, characterized in that: The cross-sectional dimensions of the convex ring (3) gradually increase or decrease in a direction approaching the supporting surface (11).

3. A fastener according to claim 1, characterized in that: It also comprises at least one anti-rotation groove (4), wherein the anti-rotation groove (4) opens on the supporting surface (11) and divides the convex ring (3) into several sections.

4. A fastener according to claim 3, characterized in that: The cross-sectional dimensions of the anti-rotation groove (4) gradually increase or decrease in a direction approaching the supporting surface (11).

5. A fastener according to claim 3, characterized in that: The anti-rotation groove (4) extends along the radial direction of the convex ring (3) and extends to the side wall of the fastener.

6. A fastener according to any one of claims 1 to 5, characterized in that: It also comprises an anti-rotation rib (5), wherein the anti-rotation rib (5) protrudes from the supporting surface (11), extends along the radial direction of the convex ring (3), and is connected to at least one of the convex rings (3).

7. A fastener according to claim 6, characterized in that: The anti-rotation rib (5) connects the adjacent convex rings (3) and / or connects the convex ring (3) and the convex navel (2).

8. A riveting assembly, characterized in that: It comprises a sheet metal (6) and a fastener as claimed in any one of claims 1 to 7, wherein the umbilicus (2) is adapted to deform so as to clamp the sheet metal (6) together with the supporting surface (11), and the convex ring (3) is adapted to penetrate into the sheet metal (6).

9. A method for processing a fastener, characterized in that: It is suitable for processing a fastener as claimed in any one of claims 1 to 7, comprising the following steps: The blank is shaped by a cold heading die so that a first groove (811) is formed on the blank (7) and a first piece (81) is obtained; Inserting a hole in the first piece (81) by a cold heading die so that the groove depth of the first groove (811) of the first piece (81) is deepened and a second groove (821) is formed on the other side to obtain a second piece (82); Using a cold heading die, the middle portion of the second piece (82) is made to protrude radially to form a first protrusion (831), thereby obtaining a third piece (83); Using a cold heading die, the third piece (83) is used to shape the first protrusion (831) to obtain a rim (841), and the first groove (811) is also shaped to form a convex navel (2), thereby obtaining a fourth piece (84); The rim (841) of the fourth piece (84) is formed into a body (1) and a convex ring (3) by a cold heading die, and the first groove (811) is further deepened to obtain a fifth piece (85); The first groove (811) and the second groove (821) of the fifth member (85) are connected by a cold heading die.

10. A punch, characterized in that: It is suitable for forming a fastener as claimed in claim 6 or 7, which comprises A protrusion (92) adapted to form the flanging hole (21) or the flanging groove; A first annular groove (93) surrounding the protrusion (92) and suitable for forming the umbilicus (2); at least two second annular grooves (94) arranged in a concentric circle, the second annular grooves (94) surrounding the first annular groove (93), the second annular grooves (94) being suitable for forming the convex ring (3), an anti-rotation groove (95), which extends along the radial direction of the second annular groove (94) and is connected with at least one of the second annular grooves (94), and is suitable for forming the anti-rotation rib (5); An exhaust hole (96) has one end opening at the bottom of the anti-rotation groove (95) and the other end opening at the side wall of the punch.

Images