Punch riveting involves using a punch to drive a solid rivet through layers of sheet metal. The punch forces the rivet until it's flush with the surface on the punch side of the material. This process is followed by reprints, where the punch and stripper presses the materials onto the embossing ring of the die, further securing the joint. Essentially, it's a method of joining materials using solid rivets and a punch to create a flush, mechanically interlocked connection.
Here's a breakdown of the process:
- Rivet Insertion: A solid rivet is positioned through aligned holes in the materials to be joined.
- Punch Action: A punch presses the rivet through the sheet metal layers.
- Flush Setting: The punch continues driving the rivet until its head becomes flush with the surface of the material on the punch side.
- Embossing (Optional): In some punch riveting processes, particularly with subsequent reprints, the punch and stripper press the materials onto an embossing ring in the die. This further deforms the rivet shank and the surrounding material, increasing the strength of the joint.
Key characteristics of punch riveting:
- Solid Rivets: Typically uses solid rivets for strength and durability.
- Flush Finish: Provides a relatively flush surface on the punch side, which can be beneficial for aesthetic or functional reasons.
- Mechanical Interlock: Creates a strong mechanical interlock between the rivet and the materials being joined.
- Suitable Applications: Commonly used in sheet metal fabrication where a strong, permanent, and relatively flush connection is required.
