Composite member and method for producing composite member

Abstract

A composite member includes a metal shaft member, and a fit member having an insertion hole and secured onto the shaft member inserted in the insertion hole. The shaft member includes a receiving portion contacting a first end surface of the fit member, a first radially enlarged portion adjacent to the receiving portion in an axial direction and tightly contacting an inner peripheral surface of the insertion hole, and a second radially enlarged portion adjacent to the first radially enlarged portion in the axial direction and tightly contacting a second end surface of the fit member opposite to the first end surface. The first and second radially enlarged portions are formed by applying a compressive load in the axial direction to the shaft member and an alternating load in a direction intersecting the axial direction to a portion of the shaft member inserted in the insertion hole.

1 . A composite member comprising:
 a shaft member made of a metal; and   a fit member having an insertion hole, the fit member being secured onto the shaft member inserted in the insertion hole,   wherein the shaft member comprises:   a receiving portion contacting a first end surface of the fit member;   a first radially enlarged portion tightly contacting an inner peripheral surface of the insertion hole, the first radially enlarged portion being disposed adjacent to the receiving portion in an axial direction of the shaft member; and   a second radially enlarged portion tightly contacting a second end surface of the fit member, the second end surface being opposite to the first end surface, and the second radially enlarged portion being disposed adjacent to the first radially enlarged portion in the axial direction.   
     
     
         2 . The composite member according to  claim 1 , wherein the fit member comprises at least one recess or projection on the second end surface, and
 wherein the second radially enlarged portion is engaged with the recess or the projection is engaged with the second radially enlarged portion.   
     
     
         3 . The composite member according to  claim 1 , wherein an opening portion of the insertion hole of the fit member on a side of the second end surface is gradually widened toward the second end surface. 
     
     
         4 . A method for producing a composite member, the method comprising: inserting a shaft member made of a metal into an insertion hole of a fit member such that a first end surface of the fit member contacts a receiving portion formed on the shaft member; and
 radially enlarging an inserted portion of the shaft member inserted in the insertion hole by applying a compressive load in an axial direction to the shaft member and an alternating load in a direction intersecting the axial direction to the inserted portion of the shaft member, thereby forming a first radially enlarged portion tightly contacting an inner peripheral surface of the insertion hole and a second radially enlarged portion tightly contacting a second end surface of the fit member, to secure the fit member onto the shaft member.   
     
     
         5 . The method according to  claim 4 , wherein at least one recess or projection is formed on the second end surface of the fit member, and
 the enlarging the inserted portion of the shaft member comprises causing the second radially enlarged portion to enter the at least one recess or causing the at least one projection to bite into the second radially enlarged portion.   
     
     
         6 . The method according to  claim 4 , wherein an opening portion of the insertion hole of the fit member on a side of the second end surface is gradually widened toward the second end surface, and
 the enlarging the inserted portion of the shaft member comprises causing an excessive material of the inserted portion enlarged inside the insertion hole to flow toward the second end surface.   
     
     
         7 . The composite member according to  claim 2 , wherein an opening portion of the insertion hole of the fit member on a side of the second end surface is gradually widened toward the second end surface. 
     
     
         8 . The method according to  claim 5 , wherein an opening portion of the insertion hole of the fit member on a side of the second end surface is gradually widened toward the second end surface, and
 the enlarging the inserted portion of the shaft member comprises causing an excessive material of the inserted portion enlarged inside the insertion hole to flow toward the second end surface.