Rivet with improved structure for forming flat-bottom riveting of plates

A rivet with improved structure for forming flat-bottom riveting of plates used for spot joining process, comprises a rivet cover, a rivet shoulder and a rivet body, wherein the rivet cover is provided with a torque transmission structure and a positioning structure for driving the rivet to rotate;

• the rivet body comprises an inner cavity of the rivet body, an outer wall of the rivet body and an end of the rivet body;
• the said inner cavity depth of the rivet body h meets the following requirements:
• h−L≤H, wherein H is the thickness of the rivet cover, D is the outer wall diameter of the rivet body, and d is the inner cavity diameter of the rivet body;
• the length L of the said rivet body and the thickness and layers of the workpiece to be connected meet the formula Σi=1n-1ti<L<Σt=1nti′, wherein ti is the thickness of the i-th layer of the workpiece to be connected, n is the number of layers of the workpiece to be connected, and n≥1;
• and
• the said inner and outer walls of rivet body are provided with a rivet body penetration structure, which can form a plurality of through holes on the rivet body and is used to discharge the to-be-connected materials trapped in the inner cavity of the rivet body to the outside of the body during the riveting process, so as to prevent forming gaps between the workpieces or deformation of the bottom of the joint as a result of trapped materials squeezing the workpieces to be connected once the cavity of the rivet body is filled with such materials.