Process assembly and article for forming an edge clinching of overlapping panels as a weight savings enabler

Abstract

A clinch forming assembly and associated process for joining first and second panels including a punch having a bottom most profile surface in combination with an inwardly stepped surface which is separated by a vertical edge surface. An overlapping arrangement of the first and second panels defines a center line of the punch aligning with an edge of the upper panel. Initial downward motion of the punch results in the inwardly stepped surface contacting an upper surface of the upper panel, with the vertical edge surface of the punch overlapping in close contact an adjoining side edge of the upper panel. Following a degree of initial deformation of the upper panel, the bottom most profile surface of the punch contacting an upper surface of the lower panel, with continued downward deformation of the punch against an opposing die located underneath the bottom panel resulting in clinching of the layers.

1 . An clinch assembly for joining first and second panels, comprising:
 a punch having a bottom most profile surface in combination with an inwardly stepped surface which is separated by a vertical edge surface;   a die having an upper profile surface with stepped support surfaces which correspond with the stepped surfaces of the punch;   an overlapping arrangement of the first and second panels positioned between the punch and die and defining a center line aligning with an edge of the upper panel, with initial downward motion of the punch resulting in the inwardly stepped surface contacting an upper surface of the upper panel, with the vertical edge surface of the punch overlapping in close contact an adjoining side edge of the upper panel; and   following a degree of initial deformation of the upper panel, the bottom most profile surface of the punch contacting an upper surface of the lower panel, with continued downward deformation of the punch against the opposing underside die located underneath the bottom panel resulting in clinching of the layers.   
     
     
         2 . A process for clinch joining first and second panels, comprising the steps of:
 providing a punch having a bottom most profile surface in combination with an inwardly stepped surface which is separated by a vertical edge surface;   providing a die having an upper profile surface with stepped support surfaces which correspond with the stepped surfaces of the punch;   positioning overlapping portions of the first and second panels between the punch and die to define a center line aligning with an edge of the upper panel;   exerting an initial downward motion of the punch, resulting in the inwardly stepped surface contacting an upper surface of the upper panel, with the vertical edge surface of the punch overlapping in close contact an adjoining side edge of the upper panel;   initially deforming the upper panel with the bottom most profile surface of the punch contacting an upper surface of the lower panel;   applying continued downward deformation of the punch against the opposing underside die located underneath the bottom panel resulting in clinching of the layers.   
     
     
         3 . The process of  claim 2 , further comprising the step of providing the first and second panels of differing strength or hardness. 
     
     
         4 . The process of  claim 3 , further comprising the step of heating the overlapping portion of the higher strength panel to an adequate temperature to induce a desired degree of flow-ability and such that, upon placing against the lower hardness panel and subsequently clinching the two panels together, the flowable material integrates with the surface layer matrix of the lower hardness panel to create a stronger clinch therebetween.