Self-piercing rivet, process and device for setting a rivet element, and employment thereof

Abstract

A fastening element ( 1 ), in particular for blind riveting, has a setting head ( 4 ), a deformation segment ( 2 ) and a shank end ( 3 ). The deformation segment ( 2 ) is arranged between the setting head ( 4 ) and the shank end ( 3 ). The fastening element ( 1 ) is hollow, optionally having a mandrel ( 7 ) inside the fastening element ( 1 ). The mandrel includes a head ( 23 ) and a foot ( 24 ) at least tension-resistantly connected to the shank end ( 3 ). The shank end ( 3 ) includes a punching edge ( 6 ) extending substantially along the outermost periphery of the shank end ( 3 ). Also identified are a process for setting the fastening element ( 1 ), a riveted connection to the fastening element ( 1 ), a device for setting the fastening element ( 1 ), an employment of the riveted connection obtained, and a die suitable for setting the fastening element ( 1 ).

1. A fastener setting system, comprising:
 a fastener including:  
 (i) a non-frangible mandrel having a foot and an enlarged head; and  
 (ii) a hollow shank including: 
 (a) a setting head at a free end;  
 (b) a deformation segment for forming a closure head;  
 (c) a connecting segment operably forming a fastenable connection with the mandrel foot; and  
 (d) a shank end opposed to the setting head having a workpiece self-piercing edge extending substantially along an outermost periphery of the shank;  
 
 a die;  
 a ram detachably connectable to the mandrel and operably advancing the fastener toward the die by pushing against the head of the mandrel.  
 
     
     
       2. The system of  claim 1 , wherein the shank and the mandrel are positively connectably geometrically. 
     
     
       3. The system of  claim 1 , wherein the shank and the mandrel are detachably connectable. 
     
     
       4. The system of  claim 3 , wherein the shank and the mandrel are threadable connectable. 
     
     
       5. The system of  claim 1 , wherein the mandrel foot and the shank end are threadable connectable. 
     
     
       6. The system of  claim 1 , comprising:
 the mandrel foot including an external thread; and  
 the shank end including an internal thread engageable with the external thread of the mandrel foot.  
 
     
     
       7. The system of  claim 1 , wherein the setting head comprises a diameter greater than any one of a deformation segment diameter, a shank end diameter and a mandrel foot diameter. 
     
     
       8. The system of  claim 1 , wherein the fastener is metal. 
     
     
       9. The system of  claim 1 , wherein a cross section of the fastener is substantially circular. 
     
     
       10. The system of  claim 1 , wherein the mandrel head comprises a fastener driving element. 
     
     
       11. The system of  claim 1 , wherein the shank comprises an open end. 
     
     
       12. A device, comprising:
 a fastening element having a setting head and a mandrel engageable into at least one part;  
 a die;  
 a ram operably punching the fastening element through the at least one part;  
 a holding tool operably holding the setting head against the at least one part; and  
 a traction tool operably retracting the mandrel;  
 wherein the ram and the holding tool are movable relative to the die independently of each other.  
 
     
     
       13. The device of  claim 12 , wherein the mandrel comprises an external thread operably forming a releasable connection with the fastening element. 
     
     
       14. The device of  claim 12 , wherein the die comprises a disposal passage operably disposing each of a plurality of punched parts. 
     
     
       15. The device of  claim 12 , comprising a counterforce structure operable to dynamically interlock the ram and the die. 
     
     
       16. The device of  claim 12 , comprising at least one of:
 a moving means;  
 a means for determining a ram position;  
 a means for determining a holding tool position; and  
 at least one force sensor operably detecting a force involved in setting a rivet.  
 
     
     
       17. A fastener setting system, comprising:
 a fastener including:  
 (i) a mandrel having a foot and a head; and  
 (ii) a hollow shank including: 
 (a) an enlarged flange adjacent a first end;  
 (b) a deformation segment deformable to form a closure head; and  
 (c) a connecting segment, adjacent an opposite second end, contacting with the mandrel foot a ram pushing against the head of the mandrel to operably advance the fastener; and  
 
 a traction tool operably pulling the mandrel relative to the shank in order to form the closure head at the deformation segment.  
 
     
     
       18. The system of  claim 17 , further comprising:
 the mandrel foot having a first diameter; and  
 an outside of the second end of the shank having a second diameter;  
 wherein the first diameter is equal to or greater than the second diameter.  
 
     
     
       19. The system of  claim 17 , wherein the fastener comprises at least one of aluminum and an aluminum alloy. 
     
     
       20. The system of  claim 17 , wherein the head of the mandrel is enlarged. 
     
     
       21. The system of  claim 17 , wherein the connecting segment of the shank has a thread which engages the foot of the mandrel. 
     
     
       22. The system of  claim 17 , further comprising:
 a die operable to create a punch opening having a variable diameter in at least one part, the die including at least two segments operably absorbing a punching force and operably forming the punch opening capable of accommodating the closure head of the fastening element;  
 a die receptacle having the segments movably lodged therein; and  
 at least one spring element operably holding the segments together.  
 
     
     
       23. The system of  claim 22 , wherein the segments are radially displaceable. 
     
     
       24. The system of  claim 22 , comprising:
 each segment including a planar bearing surface; and  
 the die receptacle including a substantially planar countersurface operably transmitting the punching force to the die receptacle.  
 
     
     
       25. The system of  claim 22 , wherein each segment comprises a spring element receptacle. 
     
     
       26. The system of  claim 22 , wherein the die receptacle comprises an annular stop. 
     
     
       27. The system of  claim 26 , further comprising:
 the annular stop including an annular stop surface; and  
 each segment including a segment stop surface;  
 wherein the segment stop surface is positionable behind the annular stop surface in relation to the at least one part by a distance ranging between 0.1 to 0.3 mm, the distance operably ensuring mobility of the segments during a fastening element selling operation.  
 
     
     
       28. The system of  claim 27 , wherein the distance ranges between 0.15 mm to 0.25 mm. 
     
     
       29. The system of  claim 22 , comprising less than five of the segments. 
     
     
       30. The system of  claim 22 , wherein the spring element comprises a rubber ring. 
     
     
       31. The system of  claim 22 , wherein the spring element comprises a spiral ring. 
     
     
       32. The system of  claim 22 , wherein the die comprises a transversely extendable vent hole. 
     
     
       33. The system of  claim 22 , wherein the punch opening formable by the segments comprises a rotationally asymmetrical cross section. 
     
     
       34. The system of  claim 33 , wherein the punch opening comprises a substantially polygonal cross section. 
     
     
       35. The system of  claim 34 , wherein the punch opening comprises a tooth when viewed in cross section. 
     
     
       36. A device, comprising:
 a self-piercing fastening element comprising a setting head and a mandrel;  
 a die;  
 a ram operably advancing the fastening element;  
 a holder operably holding the setting head; and  
 a retractor operably retracting the mandrel;  
 wherein the ram and the holder are movable relative to the die independently of each other in at least one operating condition.  
 
     
     
       37. The device of  claim 36 , wherein the die further comprises movable die segments surrounding a central passageway. 
     
     
       38. The device of  claim 36 , further comprising a force sensor. 
     
     
       39. The device of  claim 36 , wherein the mandrel includes an enlarged head. 
     
     
       40. The device of  claim 36  further comprising a hollow shank extending from the setting head. 
     
     
       41. The device of  claim 40 , further comprising at least a second workpiece retained to a first workpiece by the shank, a portion of the setting head being disposed between the workpieces and an attached accessory. 
     
     
       42. The device of  claim 36 , wherein the mandrel is non-frangible. 
     
     
       43. The device of  claim 36 , wherein the mandrel includes a frangible stem and an enlarged head opposite the ram. 
     
     
       44. The device of  claim 36 , wherein the ram includes the mandrel and the fastening element includes an expandable shank, the mandrel being threadably engageable with the shank. 
     
     
       45. The device of  claim 36 , wherein the mandrel comprises an external thread operably forming a releasable connection with the fastening element. 
     
     
       46. The device of  claim 36 , further comprising workpieces receiving the fastening element, wherein the die comprises a disposal passage operably disposing each of a plurality of punched parts of the workpieces. 
     
     
       47. The device of  claim 36 , further comprising a counterforce structure operable to dynamically interlock the ram and the die. 
     
     
       48. The device of  claim 36 , wherein the ram directly contacts against and pushes the mandrel toward the die.