CN221591482U

CN221591482U - Self-piercing press riveting nut for GPa-grade ultra-high strength steel

Info

Publication number: CN221591482U
Application number: CN202323603640.5U
Authority: CN
Inventors: 李军正; 俞言杰
Original assignee: Jiangsu Nate New Energy Vehicle Connection System Co ltd
Current assignee: Jiangsu Nate New Energy Vehicle Connection System Co ltd
Priority date: 2023-12-28
Filing date: 2023-12-28
Publication date: 2024-08-23
Anticipated expiration: 2033-12-28

Abstract

The utility model relates to a self-piercing press-riveting nut for GPa-grade ultra-high strength steel, which belongs to the technical field of self-piercing press-riveting, and comprises a nut body, wherein the tensile strength of the nut body is more than or equal to 1500MPa, the plasticity is more than or equal to 1300MPa, and the hardness is more than or equal to 500HV; the nut body is axially provided with a first central hole, the lower end surface of the nut body is axially and sequentially provided with a key tooth table and a self-piercing cone column, the key tooth table comprises a plurality of key teeth which are circumferentially and alternately distributed, tooth grooves are arranged between adjacent key teeth, and the self-piercing cone column is located on the table surface of the key tooth table between the tooth grooves and the first central hole in an inverted cone shape; the self-penetration depth H1 is from the surface of the puncture conical column to the surface of the tooth groove, the self-penetration depth H1 is smaller than the thickness H2 of the GPa-level ultra-high strength steel plate to be riveted, and the relation between the thickness H2 of the ultra-high strength steel plate to be riveted and the self-penetration depth H1 is as follows: h2 is more than H1 and is more than or equal to 0.8H2. The utility model solves the technical problem that the GPa-level ultra-high strength steel plate riveting nut is easy to fall off, prolongs the service life of the GPa-level ultra-high strength steel plate riveting nut, and reduces the manufacturing and product cost.

Description

Self-piercing press riveting nut for GPa-grade ultra-high strength steel

Technical Field

The utility model relates to the technical field of self-piercing riveting, in particular to a self-piercing riveting nut for GPa-level ultrahigh-strength steel.

Background

The light weight of automobiles promotes the wide application of emerging light materials, and the rapid development of various riveting technologies, such as self-drilling riveting technology, self-piercing friction riveting technology and the like, is initiated. The self-punching rivet nut is often applied to various aluminum sheet metal or low-strength steel sheet metal parts due to simple process, high connection strength and low cost, but in recent years, the application of high-strength steel sheet metal with the strength of more than 1000MPa is a trend, and the 10-grade and 12-grade rivet nuts commonly used in the fastener industry at present cannot self-pierce the steel plates, so that engineering application is urgent to solve the problem.

Currently, the 10-level and 12-level nuts cannot self-puncture and rivet the strength of high-strength steel above 1000MPa, the high-strength steel needs to be drilled with laser, then is connected with the rivet nut in a riveting mode, the drilled hole is improperly matched with the nut, the riveting falling risk is high, the connecting strength is low, the sealing performance is poor, and the perforating cost is high. In addition, the existing self-piercing riveting nut structure is not suitable for high-strength steel riveting, carburization is needed for pursuing high hardness, hardness is high, plasticity is poor, and cracking risk exists.

The prior art searches and discovers that the publication number is CN219197861U, and discloses a high-strength press-riveting nut, which comprises a main body, the up end center department fixedly connected with connecting block of main body, the upper end fixedly connected with guide way of connecting block, the inside wall center of guide way is provided with the clamping table near upper end department, be provided with the knurling tooth on the lateral wall of connecting block, be provided with the internal thread on the inside wall of main body. In the technology, the high-strength press-riveting nut cannot be suitable for press-riveting connection of GPa-grade steel due to materials and the like.

Disclosure of utility model

Aiming at the defects in the prior art, the utility model aims to provide a self-piercing rivet nut for GPa-grade ultrahigh-strength steel.

The self-piercing rivet nut for the GPa-level ultrahigh-strength steel comprises a nut body, wherein the tensile strength of the nut body is more than or equal to 1500MPa, the plasticity of the nut body is more than or equal to 1300MPa, and the hardness of the nut body is more than or equal to 500HV;

The nut comprises a nut body, wherein a first central hole is formed in the axial direction of the nut body, a key tooth table and a self-piercing cone column are sequentially formed on the lower end surface of the nut body in the axial direction, the key tooth table comprises a plurality of key teeth which are circumferentially distributed at intervals, tooth grooves are formed between adjacent key teeth, and the self-piercing cone column is located on the table surface of the key tooth table between the tooth grooves and the first central hole in an inverted cone shape;

The surface of the self-piercing taper column to the surface of the tooth groove are self-piercing depth H1, the self-piercing depth H1 is smaller than the thickness H2 of the GPa-level ultra-high strength steel plate to be riveted, and the relation between the thickness H2 of the ultra-high strength steel plate to be riveted and the self-piercing depth H1 is as follows: h2 is more than H1 and is more than or equal to 0.8H2.

In some embodiments, the relationship between the outer diameter Φ1 of the self-piercing tapered cylinder and the aperture M of the first central bore is: phi 1 = m+ (1.5-4.0) mm.

In some embodiments, the number of the key teeth is 3 or more, and the key teeth are uniformly distributed along the circumferential direction.

In some embodiments, the key teeth are horn-shaped, including the horn mouth section that is the splayed that connects gradually and the horn section that is the rectangle, the horn mouth section with the web structure of key tooth platform meets, the horn section is followed the radial setting of key tooth platform.

In some embodiments, the horn section has a width of 0.5 to 1.0mm.

In some embodiments, the tooth slot is in a horizontal C shape, an arc-shaped protruding section is arranged at the middle part of the tooth slot, and the projection edge of the arc-shaped protruding section in the axial direction does not exceed the projection edge of the self-piercing cone column in the axial direction.

In some embodiments, the nut body is made of ultra-high strength alloy steel.

In some embodiments, the nut body surface is coated with a zinc aluminum coating.

Compared with the prior art, the utility model has the following beneficial effects:

1. according to the self-piercing riveting nut for the GPa-level ultrahigh-strength steel, the nut body is formed by adopting the high-strength alloy steel material, the self-piercing depth is designed to be slightly smaller than the thickness of the GPa-level ultrahigh-strength steel plate to be riveted, so that the deformation of the steel plate subjected to compressive deformation is concentrated on the outer peripheral surface of a piercing cone body without overflowing when the steel plate subjected to compressive deformation is stamped and sheared off, the cohesive force on the nut body is improved, the acting force of the nut body moving towards the outer part of the steel plate caused by external force capable of effectively opposite external vibration and other factors is improved, the technical problem that the GPa-level ultrahigh-strength steel plate riveting nut is easy to fall off is solved, the service life of the GPa-level ultrahigh-strength steel plate after the riveting nut is prolonged, the riveting process flow is simplified, the manufacturing cost and the product cost are reduced, and the production effect is improved.

2. According to the self-piercing riveting nut for the GPa-level ultrahigh-strength steel, the riveting firmness of the riveting nut is further improved by optimizing the structural design of the key tooth platform.

Drawings

Other features, objects and advantages of the present utility model will become more apparent upon reading of the detailed description of non-limiting embodiments, given with reference to the accompanying drawings in which:

FIG. 1 is a schematic diagram of a three-dimensional structure of a self-piercing clinch nut for GPa-grade ultra-high strength steel;

FIG. 2 is a schematic diagram of a side view structure of the self-piercing clinch nut for GPa-grade ultra-high strength steel;

FIG. 3 is a schematic structural view of the self-piercing clinch nut of the present utility model clinched into a GPa grade ultra-high strength steel plate;

Detailed Description

The present utility model will be described in detail with reference to specific examples. The following examples will assist those skilled in the art in further understanding the present utility model, but are not intended to limit the utility model in any way. It should be noted that variations and modifications could be made by those skilled in the art without departing from the inventive concept. These are all within the scope of the present utility model.

Example 1

The embodiment provides a self-piercing press-riveting nut for GPa-level ultra-high strength steel, which comprises a nut body 100 as shown in figures 1-3, wherein the nut body 100 is formed by high-strength alloy steel with tensile strength more than or equal to 1500MPa, plasticity more than or equal to 1300MPa and hardness more than or equal to 500HV, and is used for press-riveting connection of the GPa-level ultra-high strength steel.

The nut body 100 is provided with a first central bore 110 extending axially therethrough. The inner circumferential surface of the first center hole 110 may be a light hole for a mating connection with a self-tapping bolt. The inner circumferential surface of the first center hole 110 may also be formed with a forward or reverse screw thread for direct screw-coupling with a bolt. The lower end surface of the nut body 100 is sequentially formed with a key gear stage 120 and a self-piercing tapered column 130 along the axial direction, and the key gear stage 120 and the self-piercing tapered column 130 are integrally formed on the nut body 100 by machining or the like. The key teeth stage 120 is in a gear-like structure and comprises a plurality of radially arranged key teeth 121, and tooth grooves 122 are formed between adjacent key teeth 121. The key teeth 121 provided in the radial direction are used to key the inside of the GPa grade ultra high strength steel to be riveted, providing a fitting clamping force while preventing the nut body 100 from rotating radially. The number of the key teeth 121 is plural, preferably 3 to 12, and the plurality of key teeth 121 are arranged in a circumferentially equidistant manner along the key tooth stage 120.

The self-piercing tapered pillar 130 has a tapered structure and is located in an inverted tapered shape on a web structure surface of the key bed 120, and the web structure surface mainly refers to a plate surface of the key bed 120 between the tooth grooves 121 and an inner peripheral surface of the first center hole 110. The self-penetration depth H1 from the surface of the piercing taper 130 to the surface of the tooth groove 122 is the depth to which the nut body 100 is embedded into the GPa-grade ultra-high strength steel plate to be riveted. The thickness H2 of the GPa-grade ultra-high strength steel plate to be riveted is greater than the self-piercing depth H1, so that after the press riveting, the edge of the self-piercing tapered column 130 of the nut body 100 is located within the surface of the GPa-grade ultra-high strength steel plate, forming a chimeric structural feature. The relation between the self-penetration depth H1 and the thickness H2 of the GPa-grade ultra-high strength steel plate is as follows: h2 is more than H1 and is more than or equal to 0.8H2.

The working principle of the self-piercing rivet nut for GPa-level ultra-high strength steel provided by the embodiment is as follows: after the nut body 100 is riveted in the GPa-grade ultra-high strength steel plate through the punching structure, the steel plate contacting with the self-piercing tapered column 130 is punched and sheared off, and the self-piercing depth H1 is smaller than the thickness H2 of the GPa-grade ultra-high strength steel plate to be riveted, so that the surface edge of the self-piercing tapered column 130 is embedded in the steel plate to form a closed structure. When the key teeth 121 are pressed into the steel plate, the steel plate at the riveting part is extruded and deformed by the typing extrusion of the key teeth 121, and the extruded and deformed part is slightly displaced towards the peripheral direction of the self-piercing tapered column 130 with smaller pressure, and the surface edge of the self-piercing tapered column 130 is embedded into the steel plate, so that the acting force generated by the slight displacement is difficult to overflow, further, steel contacted with the inclined peripheral surface of the self-piercing tapered column 130 has larger cohesive force on the self-piercing tapered column 130, and the axial component force of the cohesive force is larger and is the same as the riveting pressing direction due to the inclined direction of the inclined surface, so that the nut body 100 is firmly riveted on the GPa grade ultra-high strength steel to form firm connection. According to the nut body formed by adopting the high-strength alloy steel material, the self-penetration depth is designed to be slightly smaller than the thickness of the GPa-level ultrahigh-strength steel plate to be riveted, so that deformation of the steel plate subjected to compression deformation is concentrated on the outer peripheral surface of the self-piercing cone body without overflowing when the steel plate subjected to compression riveting is sheared off, the cohesive force on the nut body is improved, the acting force of the nut body moving towards the outside of the steel plate caused by external force of external vibration and other factors can be effectively opposite, the technical problem that the GPa-level ultrahigh-strength steel plate compression riveting nut is easy to fall off is solved, the service life of the GPa-level ultrahigh-strength steel plate after the nut is riveted is prolonged, the riveting process flow is simplified, the manufacturing cost and the product cost are reduced, and the production effect is improved.

In this embodiment, the ultra-high strength steel of GPa grade is mainly 1000-2000MPa steel, and the structure of the nut body 100 is preferable for a plate having a thickness of 2.5mm or less.

In some embodiments, the relationship between the outer diameter Φ1 of the self-piercing tapered cylinder 130 and the inner diameter M of the first central bore 110 is: phi 1 = m+ (1.5-4.0) mm. Under the size constraint, the structural strength of the self-piercing tapered column 130 can be ensured, and the service life is prolonged.

Further, the outer peripheral surface of the self-piercing tapered pillar 130 is a non-smooth surface, which is mainly a rough surface formed by sanding, spraying, or the like, and increases the friction coefficient with the material in the steel sheet, thereby improving the anti-falling effect.

Example 2

In embodiment 3, the structure design of the key teeth table is optimized to further improve the riveting firmness of the press-riveting nut on the basis of embodiment 1 or embodiment 2. Specifically:

As shown in fig. 1 to 3, the key teeth 121 provided on the key tooth stage 120 are in a horn-like structure, and include a horn barrel section having a substantially rectangular shape and a horn mouth section having a substantially splayed shape, a large mouth surface of the horn mouth section is integrally connected with the web structural surface, one end of the horn barrel section having a substantially rectangular shape is integrally connected with a small mouth surface of the horn mouth, and the other end of the horn barrel section extends radially to the outer peripheral surface of the peripheral nut body 100. The horn structure can guide deformation of the steel plate due to extrusion to the direction of the outer peripheral surface of the self-piercing spike 130 when the key teeth 121 are pressed into the steel plate, thereby providing a better axial pushing pressure to the outer peripheral surface of the self-piercing spike 130. Further, the width L of the horn section of the key teeth 121 is designed to be 0.5-1.0mm, and according to experimental study of practical production data, when the tensile strength of the GPa-grade ultra-high strength steel is less than or equal to 1500MPa, the width L is preferably 0.5-1.0mm, and when the tensile strength of the GPa-grade ultra-high strength steel is more than or equal to 1500MPa, the width L is preferably 0.5-0.8 mm. The design of width can satisfy the degree of firmness of riveting and riveting under panel beating tensile strength betterly this moment.

Further, the tooth grooves 122 between two adjacent key teeth 121 are of a bowl-shaped structure, wherein the bowl-shaped structure is a C-shaped structure with a larger opening in a side projection of the bowl, and the middle part of the bowl-shaped structure is an arc-shaped protruding section 1221 facing to a direction far from the center of the first center hole 110. The projected edge of the arcuate convex segment 1221 in the axial direction does not exceed the projected edge of the self-piercing spike 130 in the axial direction. The arc-shaped bulge 1221 is located in the middle of the tooth groove 122, so that the tooth groove has a fluctuation shape change, riveting firmness between the press-riveting nut and the steel plate can be improved, and meanwhile, the edge of the arc-shaped bulge 1221 is located in the edge of the self-piercing cone 130, so that the extruded and deformed steel can be slightly displaced towards the outer peripheral surface of the self-piercing cone 130, and interaction force between the steel and the self-piercing cone 130 can be guaranteed.

In the description of the present application, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, are merely for convenience in describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present application.

The foregoing describes specific embodiments of the present utility model. It is to be understood that the utility model is not limited to the particular embodiments described above, and that various changes or modifications may be made by those skilled in the art within the scope of the appended claims without affecting the spirit of the utility model. The embodiments of the utility model and the features of the embodiments may be combined with each other arbitrarily without conflict.

Claims

1. The self-piercing rivet nut for the GPa-level ultra-high strength steel is characterized by comprising a nut body (100), wherein the tensile strength of the nut body (100) is more than or equal to 1500MPa, the plasticity is more than or equal to 1300MPa, and the hardness is more than or equal to 500HV;

the nut comprises a nut body (100), wherein a first central hole (110) is formed in the axial direction of the nut body (100), a key tooth table (120) and self-piercing cone columns (130) are sequentially formed in the axial direction of the lower end surface of the nut body (100), each key tooth table (120) comprises a plurality of key teeth (121) which are distributed at intervals along the circumferential direction, tooth grooves (122) are formed between every two adjacent key teeth (121), and each self-piercing cone column (130) is located on the table surface of each key tooth table (120) between each tooth groove (122) and each first central hole (110) in an inverted cone shape;

the surface of the self-piercing taper column (130) to the surface of the tooth groove (122) are self-piercing depth H1, the self-piercing depth H1 is smaller than the thickness H2 of the GPa-level ultra-high strength steel plate to be riveted, and the relation between the thickness H2 of the ultra-high strength steel plate to be riveted and the self-piercing depth H1 is as follows: h2 is more than H1 and is more than or equal to 0.8H2.

2. The self-piercing clinch nut for GPa grade ultra high strength steel of claim 1, wherein the relationship between the outer diameter Φ1 of the self-piercing tapered post (130) and the aperture M of the first central bore (110) is: phi 1 = m+ (1.5-4.0) mm.

3. The self-piercing clinching nut for GPa grade ultra-high strength steel according to claim 1, wherein the number of the key teeth (121) is 3 or more, and the key teeth (121) are uniformly distributed along the circumferential direction.

4. A self-piercing clinch nut for ultra-high strength steel of grade GPa as set forth in claim 3 wherein said key teeth (121) are trumpet-shaped comprising a splayed flare section and a rectangular flare section connected in sequence, said flare section being in contact with the web structure of said key teeth stage (120), said flare section being disposed radially of said key teeth stage (120).

5. The self-piercing clinch nut for ultra-high strength steel of GPa grade of claim 4, wherein the trumpet section has a width of 0.5 to 1.0mm.

6. The self-piercing clinch nut for GPa grade ultra-high strength steel as set forth in claim 4, wherein said tooth slot (122) is generally in a transverse C-shape, an arc-shaped convex section (1221) is provided in a middle portion of said tooth slot (122), and a projection edge of said arc-shaped convex section (1221) in an axial direction does not exceed a projection edge of said self-piercing spike (130) in an axial direction.

7. The self-piercing clinch nut for GPa grade ultra-high strength steel as in claim 1, wherein the nut body (100) is made of ultra-high strength alloy steel.

8. Self-piercing clinch nut for ultra-high strength steel of GPa grade according to any of claims 1-7, characterized in that the surface of the nut body (100) is coated with a zinc-aluminium coating.