Tool and method for joining material layers

Abstract

A tool configured to join at least two material layers, of which at least one material layer is in the form of a metal material layer, by a pin. The tool includes a driving-in device which drives the pin through the at least two material layers to be joined, and a welding device which, after the driving-in of the pin, welds at least one first section of the pin to the at least one metal material layer.

What is claimed is: 
     
         1 . A tool configured to join at least two material layers, of which at least one material layer is composed of a metal, the tool comprising:
 a driving-in device configured to drive a pin through the at least two material layers to be joined; and   a welding device configured such that, after the driving-in of the pin, to weld at least one first section of the pin to the at least one material layer composed of the metal.   
     
     
         2 . The tool of  claim 1 , wherein the at least first section of the pin bears against a front end of the pin in the driving-in direction. 
     
     
         3 . The tool of  claim 1 , wherein the welding device conducts a welding current through the pin. 
     
     
         4 . The tool of  claim 1 , wherein the welding device welds ends of the pin to a respective one of the at least two material layers. 
     
     
         5 . The tool of  claim 1 , wherein the driving-in device is configured such that the pin is driven pneumatically through the surface of the at least two material layers. 
     
     
         6 . The tool of  claim 1 , wherein the tool is configured to prestress the at least two material layers against one another before the pin is driven through the surface of the at least two material layers. 
     
     
         7 . A method for joining at least two material layers, of which at least one material layer is composed of a metal, the method comprising:
 providing a tool including a driving-in device and a welding device;   providing a fastener;   driving the fastener using the drive-in device through the surface of the at least two material layers; and then   welding the fastener using the welding device to the at least one metal material layer after driving the fastener.   
     
     
         8 . The method of  claim 7 , wherein at least one of the material layers is composed of a plastic. 
     
     
         9 . The method of  claim 7 , wherein at least one of the material layers is composed of a fibre-plastic composite. 
     
     
         10 . The method of  claim 9 , wherein the fibre-plastic composite comprises glass-fibre-reinforced plastic. 
     
     
         11 . The method of  claim 7 , wherein the at least one metal material layer is formed by a metal auxiliary element. 
     
     
         12 . The method of  claim 7 , wherein:
 the at least two material layers comprises a first, outermost metal material layer, second and third inner non-metal material layers, and a fourth, outermost metal material layer;   the fastener comprises an elongated, headless pin; and   welding the fastener comprises creating a welded connection at a first contact point between a first distal end of the elongated pin and the first, outermost metal material layer and a second contact point between a second distal end of the elongated pin and the fourth, outermost metal material layer.   
     
     
         13 . The method of  claim 7 , wherein:
 the at least two material layers comprises a first, outermost metal material layer, a second inner non-metal material layer, and a third, outermost non-metal material layer;   the fastener comprises an elongated pin having a pin head at a distal end thereof;   driving the fastener comprises fixing the third, outermost non-metal material layer via the pin head; and   welding the fastener comprises creating a welded connection at a contact point between a distal end of the elongated pin and the first, outmost metal material layer.   
     
     
         14 . The method of  claim 7 , wherein:
 the at least two material layers comprises a first and second non-metal material layers;   the fastener comprises an elongated pin having a pin head at a distal end thereof;   driving the fastener comprises fixing the first non-metal material layer via the pin head; and   welding the fastener comprises providing a weldable metal material at a contact point on the second non-metal material layer and then creating a welded connection at the contact point between a distal end of the elongated pin, the weldable metal material and the second non-metal material layer.   
     
     
         15 . The method of  claim 7 , wherein:
 the at least two material layers comprises a first and second non-metal material layers;   the fastener comprises a headless, elongated pin; and   welding the fastener comprises providing a first weldable metal material at a first contact point on the first non-metal material layer and a second weldable metal material at a second contact point on the second non-metal material layer, and then creating a first welded connection at the first contact point between a first distal end of the elongated pin, the first weldable metal material and the first non-metal material layer, and a second welded connection at the second contact point between a second distal end of the elongated pin, the second weldable metal material and the second non-metal material layer.   
     
     
         16 . A method for joining at least two material layers, of which at least one material layer is composed of a metal, the method comprising:
 pre-stressing the material layers;   driving a fastener into the material layers; and then   creating a welded connection at at least one contact point between the fastener and the metal material layer after driving the fastener by conducting a welding current through the fastener.   
     
     
         17 . The method of  claim 16 , wherein the at least two material layers comprises:
 a first, outermost layer;   second and third inner layers; and   a fourth, outermost layer.   
     
     
         18 . The method of  claim 17 , wherein:
 the innermost layer and the outermost layer are each composed of metal material; and   the intermediary layers composed of glass-fibre-reinforced plastic (GFRP).   
     
     
         19 . The method of  claim 17 , wherein driving the fastener comprises driving the fastener through the material layers in a manner such that a portion of the fastener protrudes through the surface of first outermost material layer and the fourth outermost material layer, respectively. 
     
     
         20 . The method of  claim 17 , wherein conducting a welding current comprises conducting a welding current through the fastener such that welds are created at contact points at the first outermost material layer and the fourth outermost material layer, respectively.