焊接异种合金的拼合紧固件
By designing the cap and core structure of the splicing fastener and combining it with resistance welding technology, the problems of brittle intermetallic compounds and cracks when welding dissimilar alloys were solved, achieving efficient and reliable welding quality and cost reduction.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SHANGHAI INST OF OPTICS & FINE MECHANICS CHINESE ACAD OF SCI
- Filing Date
- 2025-06-16
- Publication Date
- 2026-07-17
AI Technical Summary
Existing technologies for welding dissimilar alloys tend to generate brittle intermetallic compounds and cracks in the weld area, resulting in unstable weld quality that fails to meet the mechanical performance requirements of the vehicle body structure. Furthermore, the fastener structure design is complex and costly.
Design a splicing fastener comprising a bowl-shaped thin-walled cap and a solid core, which are formed into an bulging structure by stamping. After the cap and core are spliced, they separate during the welding process, and a reliable connection is achieved by utilizing the mechanical anchoring effect. Combined with resistance welding technology, a stable connection between the core and the second alloy layer is ensured.
It reduces the number of stamping operations in fastener manufacturing, improves forming quality and reliability, reduces manufacturing costs, ensures welding quality and production efficiency, adapts to fast-paced stamping manufacturing processes, prevents the lower end face of the cap from piercing the surface of the first alloy, and improves the overall performance of the weld.
Smart Images
Figure CN224508679U_ABST
Abstract
Claims
1. A fastener for welding dissimilar alloys, used for resistance spot welding of laminated components of a first alloy and a second alloy, wherein the first alloy is a light metal, characterized in that, include: The bowl-shaped thin-walled cap (100) has a hollow structure with an opening on one side, the opening end of which forms the lower end face (101) of the cap, and the side wall (102) transitions to the upper end face through the arc-shaped area (103); A solid core (200) is coaxially disposed in the central region inside the cap (100) and has a shaft (201) and a flange (202) extending outward from the upper end of the shaft. The bottom surface (203) of the core (200) is coplanar with or recessed within the plane of the lower end surface (101) of the cap (100); The wall thickness T of the cap (100) ranges from 0.85Tm to Tm, where Tm is the maximum wall thickness of the cap; the cap (100) is provided with a number of bulging structures (107) distributed at equal angles in the circumferential direction. The bulging structure forms an outward convex area (108) by stamping and plastically deforming a local area of the cap, and the local outward convex area of the bulging structure is squeezed to the core to generate a mechanical anchoring effect; During the welding process, the bulging structure separates from the core, causing the bulging structure to completely lose its mechanical anchoring function for the formation of the core.
2. The split fastener of claim 1, wherein The maximum wall thickness Tm of the cap ranges from 0.2 mm to 0.5 mm.
3. The split fastener of claim 1, wherein The bulging structure is formed by additional extrusion and indentation of a local area of the cap after the cap and core are assembled. The minimum wall thickness Tb of the local area of the bulging structure is greater than 0.25Tm, where Tm is the maximum wall thickness of the cap.
4. The split fastener of claim 1, wherein The cap is provided with a positioning groove (105) that is recessed from the outer surface inward and distributed in a circumferential ring. Its longitudinal sidewall (106) is in clearance fit with the outer sidewall (206) of the flange (202) to precisely define the installation position of the core.
5. The split fastener of claim 4, wherein The bulging structure is located in the positioning ladder groove area, causing the longitudinal sidewall (106) of the positioning ladder groove to deform locally to form an outward convex area, which mechanically anchors the core.
6. The split fastener of claim 1, wherein The lower end face of the cap is provided with a flange structure that extends radially outward, and the lateral width Lf of the flange structure and the maximum wall thickness Tm of the cap satisfy: 3×Tm≤Lf≤6×Tm.
7. The split fastener of claim 1, wherein The cap includes a cap side panel and an arc-shaped area; the arc-shaped area extends from the upper end of the cap side panel in an arc to the upper end face of the cap, and forms a bend structure when it expands radially inward, causing a local area of the arc-shaped area to be higher than the upper end face of the cap, thereby forming an inwardly concave contour on the upper end face of the cap.
8. The split fastener of claim 1, wherein The upper surface of the cap has an inwardly concave profile and only partially contacts the top surface (208) of the core.
9. The split fastener of claim 4, wherein The outer sidewall H2 of the flange and the height H1 of the positioning ladder groove satisfy the following condition: H2 < H1 ≤ 3 × H2.
10. The split fastener of claim 1, wherein After the splicing fasteners are welded, at least a portion of the contact interface between the upper surface of the cap and the top surface of the core achieves a firm connection through a metallurgical bonding process.
11. The split fastener of any of claims 1-10, wherein, After the core and the cap are assembled, the bulging structure produces a mechanical anchoring effect on the outer edge of the flange of the cap. The upper surface of the core is in close contact with the upper end face of the cap, and the gap between the two does not exceed 0.1 mm.
12. The splicing fastener according to claim 11, characterized in that, The arc-shaped area (103) forms a back-bending structure, and the highest point protrudes from the upper end surface (104) of the cap by 0.3-1.0 mm; The sidewall (204) of the core shaft part (201) is a circular arc transition surface connecting the core bottom surface (203) and the flange part (202).