Method for joining surface materials by using a joining element such as bolts or nuts, comprises welding the joining element with the surface material under mechanical load by resistance heating or inductive heating

摘要

The method comprises welding a joining element (6) such as bolts or nuts with surface materials (2, 3) under mechanical load by resistance heating or inductive heating. The joining element consists of a material suitable for welding and has an edge or tip, which is selected from the forms of closed rotating edge, discontinuously rotating edge, straight edge and straight, convex or concave conical edge tip. The edge or tip is driven through one of the surface materials before welding. The current (8) is impressed to 0.5-60 kA. The current flow is maintained at 1-2000 ms. The method comprises welding a joining element (6) such as bolts or nuts with surface materials (2,3) under mechanical load by resistance heating or inductive heating. The joining element consists of a material suitable for welding and has an edge or tip, which is selected from the forms of closed rotating edge, discontinuously rotating edge, straight edge and straight, convex or concave conical edge tip. The edge or tip is driven through one of the surface materials before welding. The current (8) is impressed to 0.5-60 kA. The current flow is maintained at 1-2000 ms. The joining element is self-welded or the welding material added to the joining element is welded. The mechanical load is adjusted to 0.5-10 kN. One of the surface materials consists of plastic material unweldable with the joining element. The surface materials consist of light-weight metal. A material connection, an interlocking connection or a frictional connection is formed between the joining element and one of the surface materials. An anitcorrosive medium is introduced in the area of a joining point. An independent claim is included for a joining element such as bolts or nuts.