Projection welding nut, and vehicle

Abstract

A projection welding nut, and a vehicle. The projection welding nut comprises a nut body (1), a sealing member (2) and welding projections (3), wherein the welding projections (3) are arranged at a welding end of the nut body (1); the welding end of the nut body (1) is provided with a first end face (1a); the nut body (1) is provided with a recess (1b) in the first end face (1a); the sealing member (2) is arranged in the recess (1b); and the sealing member (2) is made of a heat-activatable expandable sealing material with an expansion ratio of 100%-300%. When the projection welding nut is in use, the sealing performance of the projection welding nut after welding can be improved.

Description

Projection weld nuts and vehicles

[0001] Cross-references to related applications

[0002] This disclosure claims priority to Chinese patent application No. 202411845177.1, filed on December 13, 2024, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This disclosure relates to the field of mechanical fastener technology, specifically to a projection weld nut and a vehicle. Background Technology

[0004] Projection weld nuts are commonly used for securing sheet metal and are widely used in industries such as automotive, shipbuilding, and construction. Taking the automotive industry as an example, projection weld nuts are typically used to connect panels at the steel-aluminum junction of the vehicle body, where waterproofing requirements are increasingly stringent. Summary of the Invention

[0005] The purpose of this disclosure is to provide a projection weld nut to improve the sealing performance of the projection weld nut after welding. Another purpose of this disclosure is to provide a vehicle.

[0006] This disclosure provides a projection weld nut, which includes a nut body, a seal, and a weld leg; the weld leg is disposed at the welding end of the nut body, the welding end of the nut body has a first end face, the nut body has a groove on the first end face, the seal is disposed in the groove, and the seal is made of a heat-activated expansion sealing material, the expansion ratio of the heat-activated expansion sealing material being 100%-300%.

[0007] In some embodiments, the heat-activated expansion sealing material can expand and reach the expansion ratio when the following conditions are met: maintained at a temperature of 120°C-200°C for 10 min-30 min.

[0008] In some embodiments, the heat-activated expansion sealing material, by weight percentage, comprises at least one of the following components: 25%-35% butyl acrylate-ethylene polymer; 21%-26% ethylene-vinyl acetate copolymer; and 14%-19% petroleum resin.

[0009] In some embodiments, the heat-activated expansion sealing material further comprises, by weight percentage, at least one of the following components: Spacamak sealant: 5%-8%; and dipentaerythritol pent-1-hexyl acrylate: 0-3%.

[0010] In some embodiments, the heat-expandable sealing material further comprises, by weight percentage, at least one of the following components: calcium carbonate: 0-3%; calcium silicate: 0-3%; and limestone: 16%-21%.

[0011] In some embodiments, the thermally expandable sealing material further comprises, by weight percentage, at least one of the following components: quartz: 0-3%; carbon black: 0-3%; dicyclohexyl phthalate: 0-3%; and zinc oxide: 2%-5%.

[0012] In some embodiments, the nut body and the seal are assembled using a hot pressing process or an injection molding process.

[0013] In some embodiments, the nut body has an axially extending threaded hole, and the groove is provided at least partially around the threaded hole.

[0014] In some embodiments, the nut body has an axially penetrating threaded hole, the weld leg is disposed on the first end face, and the groove is located between the threaded hole and the weld leg.

[0015] In some embodiments, the weld foot has a first outer side wall, the nut body has a third outer side wall, and the first outer side wall and the third outer side wall are flush; and / or, there are multiple weld feet, and the multiple weld feet are evenly spaced along the circumference of the nut body.

[0016] In some embodiments, the weld foot has a first outer side wall and a second outer side wall that are radially opposite to the nut body, and the weld foot has a second end face that faces away from the nut body; the first outer side wall and the second end face are connected by an arcuate transition; and / or, the second outer side wall and the second end face are connected by an arcuate transition.

[0017] In some embodiments, the radius of the arc surface is 0.3mm-0.8mm.

[0018] In some embodiments, the depth of the groove is defined as H, the thickness of the seal is defined as H1, and H>H1; and / or, the inner diameter of the outer ring of the groove is defined as D, and the outer diameter of the seal is defined as D1, and D>D1.

[0019] In some embodiments, H = H1 + (0.2mm - 1.0mm); and / or, D = D1 + (0.1mm - 0.2mm).

[0020] In some embodiments, both the groove and the seal have rectangular axial sections.

[0021] In some embodiments, the projection weld nut is used to engage with a bolt to connect two panels of the vehicle; the heat-activated expansion sealant can be heated and expanded during the whole-vehicle electrophoresis process after the weld foot is welded.

[0022] This disclosure also provides a vehicle comprising two panels to be connected and the aforementioned projection weld nuts; the projection weld nuts are used to engage with bolts to connect the two panels.

[0023] The vehicle provided in this disclosure, having included the aforementioned projection weld nut, also possesses all the beneficial effects of the aforementioned projection weld nut, which will not be elaborated upon here. Attached Figure Description

[0024] Figure 1 is a schematic diagram of the projection weld nut of the embodiment provided in this disclosure.

[0025] Figure 2 is a schematic diagram of the structure of the nut body and the weld leg shown in Figure 1.

[0026] Figure 3 is a schematic diagram of the seal shown in Figure 1.

[0027] Figure 4 is an axial sectional view of the seal shown in Figure 1.

[0028] Figure 5 is a partial sectional view of the nut body shown in Figure 1 at the groove position.

[0029] Reference numerals: 1-nut body, 1a-first end face, 1b-groove, 1c-threaded hole, 1d-third outer wall surface; 2-seal; 3-weld foot, 3a-first outer wall surface, 3b-second outer wall surface, 3c-second end face. Detailed Implementation

[0030] To enable those skilled in the art to better understand the present disclosure, the present disclosure will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0031] It should be noted that in this disclosure, the terms "first," "second," etc., are used only for the convenience of describing two or more structures or components that are identical or similar in structure and / or function, and do not indicate any special limitation on order and / or importance.

[0032] In this disclosure, "and / or" merely describes the relationship between related objects, indicating that there can be three relationships. For example, A and / or B can represent three situations: A exists alone, A and B exist simultaneously, and B exists alone.

[0033] In related technologies, projection weld nuts typically have annular weld legs on the welding end face, which are melted by an electric current to weld to the panel. While this type of projection weld nut provides a certain degree of waterproofing after welding, the annular weld legs are prone to incomplete welds or poor welding stability due to the influence of welding equipment and processes. This results in gaps between the welding end of the projection weld nut and the panel, leading to poor waterproofing performance on most panels and a higher risk of leakage between panels.

[0034] Therefore, how to provide a solution to overcome or alleviate the above-mentioned defects remains a technical problem that urgently needs to be solved by those skilled in the art.

[0035] Please refer to Figure 1, which is a schematic diagram of the structure of the projection weld nut of the embodiment provided in this disclosure.

[0036] In the embodiments provided in this disclosure, the projection weld nut includes a nut body 1, a sealing element 2, and a weld leg 3. The weld leg 3 is disposed at the welding end of the nut body 1, and the welding end of the nut body 1 has a first end face 1a. The nut body 1 has a groove 1b on the first end face 1a, and the sealing element 2 is disposed in the groove 1b. The sealing element 2 is made of a heat-activated expansion sealing material, and the expansion ratio of the heat-activated expansion sealing material is 100%-300%. It can be understood that the welding end of the nut body 1 is the end used for welding to the panel in the axial direction, and it is also the end where the weld leg 3 is disposed for welding.

[0037] Thus, during use, the welding foot 3 can be melted by the action of electric current to weld the nut body 1 to the corresponding panel. The projection weld nut and the panel then form an assembly. When the assembly is heated, the seal 2 inside the groove 1b can be activated by the heat to expand and flow fully, filling the gap between the welding end of the nut body 1 and the panel. This improves the sealing performance of the projection weld nut after welding, making it difficult for external moisture to enter between the panels through the welding position, thereby reducing the risk of water leakage between the panels. At the same time, the expansion ratio of the heat-activated expansion sealant is 100%-300%, which allows for effective control of the expansion amount of the seal 2. This ensures that there is enough expansion to seal the gap and guarantee the sealing performance of the projection weld nut after welding, while also preventing the seal 2 from overflowing after expansion, thus ensuring the quality of the assembled panels.

[0038] It is not difficult to understand that the heat-activated expansion sealing material used in the sealing element 2 of the projection weld nut provided in the above embodiments of this disclosure is a type of sealing medium that can expand and flow in response to heat after being heated for a certain period of time at a certain temperature, and can then solidify after the temperature drops. Specifically, it can be a sealant, adhesive, or viscous sealant, etc.

[0039] In actual setup, the temperature and time for thermal activation of the aforementioned heat-activated expansion sealing material are not limited and can be set according to sealing requirements.

[0040] In the embodiments provided in this disclosure, the above-mentioned heat-activated expansion sealing material can expand and reach the above-mentioned expansion ratio (i.e., expansion of 100%-300%) when the following conditions are met: maintained at a temperature of 120°C-200°C for 10 min-30 min.

[0041] In this way, it can ensure the improved sealing performance of the seal 2 after welding the projection weld nut, so that the projection weld nut can meet the watertight requirement IPX7 (Ingress Protection Rating 7) and the relevant requirements of the vehicle's normal aging ability, such as the sealing requirements under the conditions of high temperature resistance of 200 degrees Celsius and high temperature and humidity aging requirements of double 85 (85°C high temperature + 85% relative humidity), and also ensure that the expansion of the seal 2 will not affect the passage of the threaded hole 1c.

[0042] In actual installation, there are no restrictions on the type and composition of the sealing material that can be thermally activated to expand.

[0043] In the embodiments provided in this disclosure, the thermally expandable sealing material, by weight percentage, comprises: 25%-35% butyl acrylate-ethylene polymer; 21%-26% ethylene-vinyl acetate copolymer; and 14%-19% petroleum resin. It is readily understood that butyl acrylate-ethylene polymer possesses good flexibility and adhesion, allowing it to adhere tightly to the surface of the object being sealed when applied in sealing applications. Under external stimuli such as temperature, the molecular structure of the butyl acrylate-ethylene polymer can be further adjusted to fully fill gaps, preventing the passage of liquids or gases. The butyl acrylate-ethylene polymer is particularly suitable for sealing environments requiring high flexibility, such as the connections of mechanical components in vehicles where slight vibrations or deformations occur.

[0044] Ethylene-vinyl acetate copolymers possess excellent heat-melting and elasticity. Under heating conditions, ethylene-vinyl acetate copolymers can soften and fill gaps, and upon cooling, they can form a stable sealing structure. Furthermore, the vinyl acetate groups in their molecular chain impart a certain polarity, enabling them to adhere well to various material surfaces. They are also suitable for applications requiring elastic sealing and maintain good sealing performance even under temperature changes.

[0045] Petroleum resins possess excellent adhesion and chemical resistance. When used, they form a viscous sealing layer at the interface, preventing the intrusion of external substances. Furthermore, their chemical stability allows them to maintain their sealing performance under various chemical environments.

[0046] As can be seen from the above, in the projection weld nut provided in the above embodiments of this disclosure, the heat-activated expansion sealing material has three sealing components: 25%-35% 2-butyl acrylate-ethylene polymer, 21%-26% ethylene-vinyl acetate copolymer, and 14%-19% petroleum resin. This gives the seal 2 high heat meltability and adhesion, allowing it to expand stably and flow fully after heating. The expansion ratio of the seal 2 after heating can be effectively controlled between 100% and 300%. After curing, it can also adhere tightly to the surface of the panel, ensuring the stability of the sealing structure near the welding position of the projection weld nut. Moreover, it gives the seal 2 high flexibility, making the projection weld nut suitable for connecting two panels that are prone to vibration or deformation in vehicles and other applications. Furthermore, it gives the seal 2 high elasticity, ensuring a good sealing effect even when the ambient temperature of the projection weld nut changes. It also allows the seal 2 to form an adhesive sealing layer at the interface, which can significantly improve the sealing performance of the projection weld nut after welding.

[0047] It is worth noting that the heat-activated expansion sealing material may include all three sealing components as shown in the above embodiments: 2-butyl acrylate-ethylene polymer, ethylene-vinyl acetate copolymer, and petroleum resin. Alternatively, it may include only one or two of these three sealants. No specific limitation is imposed.

[0048] In the embodiments provided in this disclosure, the thermally expandable sealing material further comprises, by weight percentage: Spakamak sealant: 5%-8%; dipentaerythritol pent-1-hexyl acrylate: 0-3%.

[0049] It's easy to understand that EnBAKGMAK sealant, as a specialized sealant, contains special polymer components and additives. It maintains its viscosity and cohesiveness under specific conditions (such as changes in temperature and pressure) to prevent fluid penetration. This sealant can be used to meet more precise sealing needs, such as the sealing requirements of critical components in aerospace, high-end machinery, and automotive fields. Dipentaerythritol pentyl-1-hexyl acrylate undergoes a polymerization reaction or physical change under suitable conditions (such as thermal activation), thereby filling gaps and achieving a sealing effect.

[0050] In the projection weld nut provided in the above embodiments of this disclosure, since the heat-activated expansion sealing material also includes 5%-8% of Sibacarmak sealant and 0-3% of dipentaerythritol pent-1-hexyl acrylate, the sealing effect after the projection weld nut is further improved, and the projection weld nut is also suitable for the connection between two panels with relatively precise sealing requirements.

[0051] It is worth noting that the product may include both Sparkamak sealant and dipentaerythritol pent-1-hexyl acrylate as shown in the above embodiments, or it may include only one of these two components; there is no specific limitation.

[0052] In the embodiments provided in this disclosure, the thermally expandable sealing material further comprises, by weight percentage: calcium carbonate: 0-3%; calcium silicate: 0-3%; limestone: 16%-21%.

[0053] It is easy to understand that calcium carbonate, calcium silicate salts, and limestone can increase the hardness and structural stability of sealing materials, making them less prone to deformation under pressure. Therefore, in the projection weld nut provided in the above embodiments of this disclosure, since the heat-activated expansion sealing material includes 0-3% calcium carbonate, 0-3% calcium silicate salts, and 16%-21% limestone, the sealing element 2, after heat-activated expansion and curing, possesses high hardness and structural stability. This ensures that the sealing structure is not easily deformed when the welded position of the projection weld nut is subjected to pressure after welding, and it can still maintain high sealing performance.

[0054] It is worth noting that, as shown in the above embodiments, calcium carbonate, calcium silicate salt and limestone can be added to the heat-activated expansion sealing material, or only one or two of these three components can be added. This disclosure does not limit this.

[0055] In the embodiments provided in this disclosure, the thermally expandable sealing material, by weight percentage, further comprises the following components: quartz: 0-3%; carbon black: 0-3%; dicyclohexyl phthalate: 0-3%; zinc oxide: 2%-5%.

[0056] It's easy to understand that quartz has certain wear resistance and chemical stability, which helps maintain the physical properties of sealing materials; carbon black can enhance the anti-aging properties and some mechanical properties of sealing materials; dicyclohexyl phthalate can act as a plasticizer, improving the flexibility and processing performance of sealing materials; zinc oxide plays multiple roles in sealing materials. For example, it can improve the thermal conductivity of sealing materials, helping to dissipate heat in some heat-generating sealing environments and preventing local overheating that could lead to sealing material failure. At the same time, it also has certain antibacterial and anti-aging properties, helping to maintain the sealing performance of sealing materials and ensuring the performance stability of sealing materials during long-term use, preventing sealing failure due to heat accumulation, microbial corrosion, and other factors.

[0057] As can be seen from the above, in the projection weld nut provided in the above embodiments of this disclosure, since the heat-activated expansion sealing material includes 0-3% quartz, 0-3% carbon black, 0-3% dicyclohexyl phthalate and 2%-5% zinc oxide, it can improve the overall performance of the seal 2. For example, it can improve the wear resistance, anti-aging performance, thermal conductivity and antibacterial properties of the seal 2 after heat-activated expansion and curing, thereby further ensuring the stability and long-term performance of the sealing performance of the projection weld nut after welding.

[0058] It is worth noting that the thermally expandable sealing material as shown in the above embodiments of this disclosure can simultaneously contain quartz, carbon black, dicyclohexyl phthalate and zinc oxide, or it can contain only one or more of these components. This disclosure does not limit this.

[0059] In actual setup, the forming method of the nut body 1 is not limited.

[0060] In the embodiments provided in this disclosure, the nut body 1 is formed by cold heading process, which makes the nut body 1 easy to manufacture, improves the production efficiency of the nut body 1, facilitates the mass production of the nut body 1, improves the utilization rate of processing materials, helps to reduce the production cost of the nut body 1, and improves the strength of the nut body 1, which helps to improve the welding quality of the projection weld nut.

[0061] In actual setup, the molding method of seal 2 is not limited.

[0062] As one option, the seal 2 can be formed using a sheet metal punching and trimming process. Specifically, based on the required shape and size of the seal 2, the sheet metal is punched and trimmed to prepare the seal 2. This simplifies the manufacturing process, improves the production efficiency of the seal 2, facilitates mass production of the seal 2, and also ensures a reliable and stable seal 2. This also promotes uniform and sufficient flow during the subsequent thermal expansion process of the seal 2, thereby improving the sealing performance of the projection weld nut after welding.

[0063] As an alternative, the seal 2 can be formed using injection molding. Specifically, a corresponding mold can be manufactured according to the required shape and size of the seal 2, and the seal 2 can be injection molded using sealing material within the mold. This simplifies the manufacturing process, improves the production efficiency of the seal 2, facilitates mass production of the seal 2, and also produces a seal 2 with high dimensional accuracy. This is beneficial for the uniform and sufficient flow of the seal 2 during subsequent thermal expansion, thereby improving the sealing performance of the projection weld nut after welding.

[0064] In actual installation, the seal 2 and the nut body 1 can be molded separately. This makes the manufacturing method of the two flexible and varied, the structure relatively simple, and the manufacturing relatively easy. Of course, the two can also be molded as one piece, and there is no specific restriction.

[0065] Specifically, the seal 2 and the nut body 1 can be assembled using a hot pressing process or an injection molding process, and this disclosure does not impose any restrictions on this.

[0066] As one option, the nut body 1 and the seal 2 can be assembled using a hot pressing process. In this case, a certain pressure can be applied at a temperature of 80°C to assemble the two. Hot pressing can achieve the bonding between the material molecules of the two, and the bonding is relatively strong. This results in a projection weld nut with high strength, excellent wear resistance, and corrosion resistance. This not only helps prevent the seal 2 and the nut body 1 from separating or breaking during the storage and transportation of the projection weld nut, but also ensures that the projection weld nut has strong welding strength, welding stability, and sealing performance after welding.

[0067] As an alternative, the nut body 1 and the seal 2 can also be assembled using an injection molding process. This not only improves the production efficiency of the projection weld nut to achieve mass production, but also enhances the bonding strength between the two, thereby increasing the welding strength of the projection weld nut.

[0068] Please refer to Figure 2 as well. Figure 2 is a schematic diagram of the structure of the nut body and weld leg shown in Figure 1.

[0069] In actual installation, the specific shape and arrangement of groove 1b are not limited.

[0070] As shown in Figure 2, in the embodiment provided in this disclosure, the nut body 1 has a threaded hole 1c that extends axially, and a groove 1b is provided at least partially around the threaded hole 1c. The threaded hole 1c is used for bolts or studs to pass through after the nut body 1 is welded to the panel, thereby connecting the two panels.

[0071] It is easy to understand that the seal 2 can have a shape that is approximately the same as the groove 1b, with the groove 1b at least partially surrounding the threaded hole 1c, making the groove 1b partially or completely annular. Correspondingly, the seal 2 can also be at least partially surrounding the threaded hole 1c, thus becoming partially or completely annular. In this way, when the seal 2 expands due to heat, the sealing material of the seal 2 can flow relatively evenly and sufficiently into the gap between the nut body 1 and the panel, thereby enhancing the sealing effect.

[0072] Specifically, the number of grooves 1b is not limited. In some embodiments, as shown in FIG2, there may be one groove 1b, which may completely surround the threaded hole 1c, that is, the groove 1b may be a complete ring. In this case, the seal 2 may also be a complete ring. When the seal 2 is heated and expands, it can flow outward from a position of up to 360 degrees around the threaded hole 1c, making the flow more uniform and more sufficient. This can further enhance the filling effect of the seal 2 on the gap between the nut body 1 and the panel, thereby further improving the sealing performance of the projection weld nut. Moreover, the groove 1b and the seal 2 of this structure are easier to process, which can improve the manufacturing efficiency of the projection weld nut.

[0073] It is worth mentioning that in some other embodiments, multiple grooves 1b can also be provided. In this case, the grooves 1b can be complete rings, and multiple grooves 1b can be distributed radially at intervals along the nut body 1 to further improve the sealing performance of the projection weld nut. The grooves 1b can also be partially ring-shaped or circular, strip-shaped or other shapes as described above. Multiple grooves 1b can be evenly distributed circumferentially along the nut body 1, or other distribution forms can be adopted. In this way, multiple grooves 1b can not only relatively ensure the sealing performance of the projection weld nut, but also relatively save the amount of sealing material used, so as to reduce the sealing cost.

[0074] Furthermore, the groove 1b can be radially spaced from the threaded hole 1c, or the inner ring side of the groove 1b can be opened, so that the groove 1b and the threaded hole 1c are connected. No specific restrictions are imposed.

[0075] In actual setup, the specific position of the weld leg 3 at the weld end of the nut body 1 is not limited, nor is its relative position to the groove 1b.

[0076] Referring to Figure 2, in the embodiment provided in this disclosure, the weld foot 3 is located on the first end face 1a, and the groove 1b is located between the threaded hole 1c and the weld foot 3. Thus, after the sealing element 2 inside the groove 1b expands due to heat, it can better seal the gap between the welded end of the nut body 1 and the panel, thereby further improving the sealing performance of the projection weld nut after welding.

[0077] Specifically, the welding foot 3 can be positioned as far away from the groove 1b as possible. In some embodiments, as shown in FIG2, the welding foot 3 can be positioned at the edge of the first end face 1a. This minimizes the impact of the welding heat generated during the welding process of the welding foot 3 on the seal 2, making the seal 2 less susceptible to thermal aging or melting due to the welding heat of the welding foot 3. At the same time, it also reduces the requirements for the temperature-resistant engineering material (ultra-high melting point requirement) of the non-metallic seal 2, giving it the advantage of universal material selection. It also enhances the fluidity of the solder and panel during melting, thereby enhancing the welding performance of the projection weld nut.

[0078] As shown in Figure 2, the weld leg 3 has a first outer wall surface 3a on the side of the nut body 1 away from the threaded hole 1c in the radial direction. The nut body 1 has an outer peripheral surface, namely the third outer wall surface 1d in Figure 2. The weld leg 3 is located at the edge of the first end face 1a. The first outer wall surface 3a of the weld leg 3 and the third outer wall surface 1d of the nut body 1 can be directly connected to further reduce the influence of the welding heat of the weld leg 3 on the seal 2. Alternatively, the first outer wall surface 3a of the weld leg 3 and the third outer wall surface 1d of the nut body 1 can have a small gap in the radial direction of the nut body 1. The specific design is not limited.

[0079] Furthermore, referring to Figure 2, in the embodiments provided in this disclosure, the first outer wall surface 3a of the weld leg 3 and the third outer wall surface 1d of the nut body 1 are flush. In other words, the outer edge of the weld leg 3 coincides with the outer edge of the first end face 1a, and there is no gap between the weld leg 3 and the outer edge of the nut body 1. This can significantly reduce the impact of the welding heat of the weld leg 3 on the seal 2, further reduce the material requirements for the seal 2, and further improve the fluidity of the solder and panel during melting, thereby further improving the welding performance of the projection weld nut.

[0080] In actual setup, the number of solder feet 3 is unlimited.

[0081] In the embodiments provided in this disclosure, as shown in FIG2, there are multiple welding feet 3, that is, more than three, which can be evenly spaced along the circumference of the nut body 1. In this way, multiple welding feet 3 can reduce the amount of solder used, thereby reducing welding costs. Moreover, it can make the structure of the nut body 1 simpler and easier to manufacture. It can also make the solder of the welding feet 3 flow more evenly during the welding process and be more evenly distributed at the welding position, so as to achieve more uniform welding between the welding end of the nut body 1 and the panel, improve welding strength and welding stability, and also improve welding efficiency.

[0082] In practical applications, the shape and size of the weld leg 3 can be roughly referenced to standard QC / T 872—2011. Based on this, it is easy to understand that the shape of the weld leg 3 can be various. It can be a strip shape as shown in Figure 2. In this case, the weld leg 3 can be roughly arc-shaped, that is, extending along the circumference of the nut body 1, and its center can be the same as the first end face 1a. Of course, the weld leg 3 can also be cylindrical or other shapes.

[0083] As shown in Figure 2, in the embodiment provided in this disclosure, the weld leg 3 has a second outer wall surface 3b that is radially opposite to the first outer wall surface 3a on the nut body 1. The second outer wall surface 3b is also the side of the weld leg 3 on the side near the threaded hole 1c. The weld leg 3 has a second end face 3c that is opposite to the nut body 1. The first outer wall surface 3a and the second end face 3c are connected by an arc surface transition, and the second outer wall surface 3b and the second end face 3c are connected by an arc surface transition. Thus, the top width of the welding leg 3 forms two rounded corners, which can significantly reduce the heat equivalent requirement of the welding leg 3 and improve the adaptability of the welding leg 3 to the welding machine parameters. This makes the welding process more controllable, allowing for stable welding operations and reducing the risk of incomplete welds. It ensures that the settlement of the projection weld nut after welding can reach 80% to 90% of the welding leg height, thereby improving welding strength and stability. It also ensures that the plastic compression of the seal 2 accounts for more than 90% of the total volume, which is beneficial to further improve the sealing effect of the seal 2 on the gap between the nut body 1 and the panel after thermal expansion.

[0084] Of course, only one of the two rounded corners can be provided, that is, only the first outer wall surface 3a and the second end surface 3c can be connected by a rounded surface, or only the second outer wall surface 3b and the second end surface 3c can be connected by a rounded surface. This disclosure does not limit this.

[0085] The radius of the aforementioned arc surface is not limited; in the embodiments provided in this disclosure, the radius of the arc surface is 0.3mm-0.8mm. This further reduces the heat equivalent requirement of the weld leg 3 and further improves the compatibility between the weld leg 3 and the welding equipment, thereby further improving the welding quality.

[0086] Please refer to Figures 3 to 5. Figure 3 is a structural schematic diagram of the seal shown in Figure 1, Figure 4 is an axial sectional view of the seal shown in Figure 1, and Figure 5 is a partial sectional view of the nut body shown in Figure 1 at the groove position.

[0087] In actual setup, the specific dimensions and relative dimensions of the groove 1b and the seal 2 are not limited. The seal 2 can completely fill the groove 1b or partially fill the groove 1b, as long as the amount of sealing material in the seal 2 is sufficient to seal the gap between the welded end of the nut body 1 and the panel after thermal expansion.

[0088] In the embodiments provided in this disclosure, the depth of the groove 1b is defined as H, and the thickness of the seal 2 is defined as H1, where H>H1; the inner diameter of the outer ring of the groove 1b is defined as D, and the outer diameter of the seal 2 is defined as D1, where D>D1. Thus, when the seal 2 and the nut body 1 are formed separately, it facilitates the assembly between the seal 2 and the nut body 1, improving production efficiency. Furthermore, considering that the seal 2 and the nut body 1 are ultimately bonded together, the bonding strength between the two can be improved, making it less prone to detachment or breakage during transportation after assembly.

[0089] It is not difficult to understand that in the above embodiments provided in this disclosure, the axial dimension of the groove 1b is greater than the axial dimension of the seal 2 and the radial dimension of the groove 1b is greater than the radial dimension of the seal 2. In fact, it is also possible that only the depth H of the groove 1b is greater than the thickness H1 of the seal 2, and only the inner diameter D of the outer ring of the groove 1b is greater than the outer diameter D1 of the seal 2. There are no specific limitations.

[0090] Furthermore, the specific differences between the groove 1b and the seal 2 in axial and radial dimensions are not limited. In some embodiments, H can be equal to H1 + (0.2mm-1.0mm), and D can be D1 + (0.1mm-0.2mm) to facilitate the assembly of the seal 2 and the nut body 1, and to further enhance the bonding strength between the two.

[0091] It is worth noting that when the seal 2 and the nut body 1 are assembled using injection molding, the radial dimension relationship between the groove 1b and the seal 2 does not have to be subject to the above restriction - D = D1 + (0.1mm - 0.2mm). Instead, their radial dimensions can be equal, that is, the inner diameter D of the outer ring of the groove 1b can be equal to the outer diameter D1 of the seal 2. This is more conducive to the molding of the seal 2 and the nut body 1, and also makes it less likely for them to fall off or break during transportation.

[0092] Specifically, when the groove 1b and the seal 2 are annular, their axial cross-sectional shapes can be rectangular, circular, or semi-circular, without any specific restrictions.

[0093] As shown in Figures 4 and 5, in the embodiments provided in this disclosure, both the groove 1b and the seal 2 have rectangular axial sections. This allows for a better fit between the seal 2 and the groove 1b, which is beneficial for further improving assembly efficiency and the sealing performance of the welded nut.

[0094] In actual setup, the temperature source for activating seal 2 is not limited.

[0095] In the embodiments provided in this disclosure, projection weld nuts are used to mate with bolts to connect two panels of a vehicle; the heat-activated expansion sealing material can be heated and expanded during the whole-vehicle electrophoresis process after the weld leg 3 is welded. Thus, the heat generated during the whole-vehicle electrophoresis process can be cleverly utilized to heat the seal 2, causing the seal 2 to expand and seal the gap between the welded end of the sealing nut body 1 and the panel. This reduces the assembly cost of connecting panels using projection weld nuts and bolts, and is also convenient to operate.

[0096] Specifically, the processing temperature and time for the whole vehicle electrophoresis treatment process are not limited. In some embodiments, the processing temperature can be 120℃-160℃, and the processing time can be 20min-30min, which can ensure that the seal 2 reaches the above-mentioned expansion ratio.

[0097] In this embodiment, after the welding of the weld foot 3 and the panel is completed, the process is carried out at a temperature of 160°C for 20 minutes during the whole vehicle electrophoresis process. This can effectively ensure that the expansion ratio of the seal 2 is within a reasonable range, so as to ensure the sealing performance of the seal 2 after the projection weld nut is welded.

[0098] Of course, after the welding of the welding foot 3 is completed, the heat generated by other subsequent processing processes can be used to activate the heat-activated expansion sealing material when performing other subsequent processing on the assembly formed by the projection weld nut and the panel, in addition to the whole vehicle electrophoresis treatment. Alternatively, after the welding of the welding foot 3 is completed, the assembly formed by the projection weld nut and the panel can be placed in a special heating device, such as an oven or heating furnace, and the heating device can be heated to the set temperature to cause the sealing element 2 to expand due to heat.

[0099] The projection weld nut provided in the above embodiments of this disclosure has a groove 1b on the welding end face of the nut body 1, and a heat-activated expansion seal 2 is provided in the groove 1b. The expansion ratio of the seal 2 is 100%-300%. After the projection weld nut and the panel are welded, the heat generated by the whole vehicle electrophoresis process can heat the assembly formed by the projection weld nut and the panel, which can activate the seal 2 and make it expand. The expansion amount of the seal 2 can be effectively controlled, so that the seal 2 flows in the gap between the welding end of the nut body 1 and the panel and finally fills the entire gap. After cooling, it can improve the sealing performance of the welding position, making it difficult for moisture to enter between the panels through the welding position, reducing the risk of water leakage between the panels. In this way, the influence of welding equipment and welding process on the sealing performance of projection weld nut can also be reduced, and it can be ensured that the seal 2 does not overflow after expansion, so as to ensure the quality of the assembled panels.

[0100] In the embodiments provided in this disclosure, this disclosure also provides a vehicle, the vehicle including two panels to be connected and the projection weld nuts in all the above embodiments; the projection weld nuts are used to engage with bolts to connect the two panels.

[0101] It is understood that the two panels can be any two plate-like components in the vehicle that need to be connected. In some embodiments, the two panels can be hot-formed steel plates located at the inner panel of the A-pillar of the vehicle, and this disclosure does not limit this. In use, a projection weld nut can be welded to one of the plate-like components, and the connection between the two plate-like components can be achieved using bolts and nuts.

[0102] The vehicle provided in this embodiment includes the projection weld nut in all the above embodiments and has all the beneficial effects of the projection weld nut in all the above embodiments, which will not be repeated here.

[0103] The projection weld nut disclosed herein has a groove on the welded end face of the nut body, and a sealing element is placed in the groove. The sealing element is made of a heat-activated expansion sealing material. When in use, the sealing element can be activated by heat to expand and flow, filling the gap between the welded end of the projection weld nut and the panel, thereby improving the sealing performance of the projection weld nut after welding. This makes it difficult for external moisture to enter between the panels through the welded position, thus reducing the risk of water leakage between the panels. At the same time, the expansion ratio of the heat-activated expansion sealing material is 100%-300%, which allows for effective control of the expansion amount of the sealing element. This ensures that there is sufficient expansion to seal the gap and guarantee the sealing performance of the projection weld nut after welding, while also preventing glue overflow after the sealing element expands, thereby ensuring the quality of installation between the panels.

[0104] This document uses specific examples to illustrate the principles and implementation methods of this disclosure. The descriptions of the embodiments above are only for the purpose of helping to understand the apparatus and core ideas of this disclosure. It should be noted that those skilled in the art can make various improvements and modifications to this disclosure without departing from its principles, and these improvements and modifications also fall within the protection scope of the claims of this disclosure.

Claims

1. A projection weld nut, characterized in that, The projection weld nut includes a nut body (1), a seal (2), and a weld leg (3); The welding foot (3) is provided at the welding end of the nut body (1). The welding end of the nut body (1) has a first end face (1a). The nut body (1) has a groove (1b) on the first end face (1a). The sealing element (2) is provided in the groove (1b). The sealing element (2) is made of a heat-activated expansion sealing material. The expansion ratio of the heat-activated expansion sealing material is 100%-300%.

2. The projection weld nut according to claim 1, characterized in that, The heat-activated expansion sealing material can expand and reach the specified expansion ratio when the following conditions are met: Keep at 120℃-200℃ for 10min-30min.

3. The projection weld nut according to claim 1 or 2, characterized in that, By weight percentage, the heat-activated expansion sealing material comprises at least one of the following components: 25%-35% butyl acrylate-ethylene polymer; 21%-26% ethylene-vinyl acetate copolymer; and 14%-19% petroleum resin.

4. The projection weld nut according to claim 3, characterized in that, By weight percentage, the heat-activated expansion sealing material further includes at least one of the following components: Spartamac sealant: 5%-8%; and Dipentaerythritol pent-1-hexyl acrylate: 0-3%.

5. The projection weld nut according to claim 3, characterized in that, The heat-activated expansion sealing material, by weight percentage, further includes at least one of the following components: calcium carbonate: 0-3%; calcium silicate: 0-3%; and limestone: 16%-21%.

6. The projection weld nut according to claim 3, characterized in that, By weight percentage, the heat-activated expansion sealing material further comprises at least one of the following components: quartz: 0-3%; carbon black: 0-3%; dicyclohexyl phthalate: 0-3%; and zinc oxide: 2%-5%.

7. The projection weld nut according to claim 1 or 2, characterized in that, The nut body (1) and the seal (2) are assembled using a hot pressing process or an injection molding process.

8. The projection weld nut according to claim 1 or 2, characterized in that, The nut body (1) has an axially penetrating threaded hole (1c), and the groove (1b) is provided at least partially around the threaded hole (1c).

9. The projection weld nut according to claim 1 or 2, characterized in that, The nut body (1) has a threaded hole (1c) that extends through the axial direction, the weld leg (3) is provided on the first end face (1a), and the groove (1b) is located between the threaded hole (1c) and the weld leg (3).

10. The projection weld nut according to claim 1 or 2, characterized in that, The weld leg (3) has a first outer side wall (3a), and the nut body (1) has a third outer side wall (1d), the first outer side wall (3a) and the third outer side wall (1d) being flush; and / or, There are multiple welding feet (3), and the multiple welding feet (3) are evenly spaced along the circumference of the nut body (1).

11. The projection weld nut according to claim 1 or 2, characterized in that, The weld leg (3) has a first outer side wall (3a) and a second outer side wall (3b) that are radially opposite to the nut body (1), and the weld leg (3) has a second end face (3c) that is opposite to the nut body (1). The first outer wall surface (3a) and the second end surface (3c) are connected by a circular arc surface transition; and / or, the second outer wall surface (3b) and the second end surface (3c) are connected by a circular arc surface transition.

12. The projection weld nut according to claim 11, characterized in that, The radius of the arc surface is 0.3mm-0.8mm.

13. The projection weld nut according to claim 1 or 2, characterized in that, The depth of the groove (1b) is defined as H, and the thickness of the seal (2) is defined as H1, where H > H1; and / or, The inner diameter of the outer ring of the groove (1b) is defined as D, and the outer diameter of the seal (2) is defined as D1, where D>D1.

14. The projection weld nut according to claim 13, characterized in that, H = H1 + (0.2mm - 1.0mm); and / or, D = D1 + (0.1mm - 0.2mm).

15. The projection weld nut according to claim 1 or 2, characterized in that, The axial cross-sections of the groove (1b) and the seal (2) are both rectangular.

16. The projection weld nut according to claim 1 or 2, characterized in that, The projection weld nut is used to mate with the bolt to connect the two panels of the vehicle; the heat-activated expansion sealant can be heated and expanded during the whole vehicle electrophoresis process after the weld foot (3) is welded.

17. A vehicle, characterized in that, The vehicle includes two panels to be connected and a projection weld nut according to any one of claims 1 to 16; The projection weld nut is used to mate with the bolt to connect the two panels.

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