Method of connecting and structure of connecting electric wire and connection terminal

Abstract

After bringing a conductor of an electric wire into press contact to connect with a wire caulking portion of a connection terminal, the conductor and the wire caulking portion are welded to connect by irradiating laser beam to a bottom wall of the wire caulking portion. Laser irradiation is carried out intermittently by three times and the laser irradiation at the second time and thereafter which is carried out later is carried out such that during a time period in which a laser welded portion immediately previously is brought into a predetermined state of elevating temperature, portions or welded regions overlap welded regions in laser irradiation irradiated previously.

What is claimed is:  
     
         1 . A method of connecting an electric wire and a connection terminal comprising the steps of; 
 crimping a conductor of the electric wire with a wire caulking portion of the connection terminal;    subsequently performing at least two times of irradiating a laser beam to the wire caulking portion for laser welding;    wherein a second laser irradiation is carried out subsequently to a first laser irradiation within a predetermined time period in which a laser welded portion welded in the first laser irradiation is brought into a predetermined state of elevating a temperature, and    a second welded region on which the second laser irradiation is carried out overlaps at least partially a first welded region on which the first laser irradiation is carried out.    
     
     
         2 . A method of connecting an electric wire and a connection terminal according to  claim 1 , wherein the time period is set not larger than 2 seconds.  
     
     
         3 . A method of connecting an electric wire and a connection terminal according to  claim 1 , wherein the connection terminal is made of a Cu alloy and the conductor is made of an aluminum series or Fe—Ni series metal.  
     
     
         4 . A method of connecting an electric wire and a connection terminal according to  claim 1 , wherein the connection terminal is made of an aluminum species material or a stainless steel species material.  
     
     
         5 . A structure of connecting an electric wire and a connection terminal wherein a conductor of the electric wire is brought into press contact with a wire caulking portion of the connection terminal is welded to the wire caulking portion by laser welding at two portions or more thereof and welded regions overlap each other at least partially.  
     
     
         6 . A structure of connecting an electric wire and a connection terminal according to  claim 5 , wherein the connection terminal is made of a Cu alloy and the conductor is made of an aluminum series or Fe—Ni series metal.  
     
     
         7 . A structure of connecting an electric wire and a connection terminal according to  claim 5 , wherein the connection terminal is made of an aluminum species material or a stainless steel species material.