Method for manufacturing housing by press working, apparatus therefor and housing thereof

Abstract

A flange part of a housing is shaped using a press working with a punch and a die, the housing including a side wall part surrounding an internal space, a bottom part that closes an opening of the side wall part in one side and the flange part bent from an opening of the side wall part in the other side towards outside. In the press working, the punch is disposed in an internal space side of the housing and the die in an opposite side of the internal space side of the housing, and a crush working is performed to crush a bend part formed from the side wall part to the flange part, while drawing at least part of an outer peripheral surface of the side wall part towards a flange part side by using the die.

What is claimed is: 
     
         1 . A method for manufacturing a housing including a side wall part surrounding an internal space, a bottom part that closes an opening of the side wall part in one side and a flange part bent from an opening of the side wall part in the other side towards outside, using press working with a punch and a die for shaping the flange part, comprising steps of:
 disposing the punch in an internal space side of the housing and the die in an opposite side of the internal space side of the housing;   performing, during the press working, crush working that crushes a bend part formed from the side wall part to the flange part, while drawing at least part of an outer peripheral surface of the side wall part towards a flange part side by using the die, thereby causing a radius of curvature of a portion in the bend part from an inner peripheral surface of the side wall part to the flange part, to be smaller and expanding a flat surface of the flange part in a punch side.   
     
     
         2 . The method for manufacturing the housing using the press working according to  claim 1 , 
       wherein
 in the crush working, a protrusion is provided on a surface of the punch opposite to the flange part, the protrusion restraining an outer peripheral end part of the flange. 
 
     
     
         3 . A manufacturing apparatus for a housing including a side wall part surrounding an internal space, a bottom part that closes an opening of the side wall part in one side and a flange part bent from an opening of the side wall part in the other side towards outside, using a press working for shaping the flange part, comprising:
 a punch disposed in an internal space side of the housing and formed corresponding to an inner shape of the housing from the bottom part to the flange part via the side wall part; and   a die disposed in an opposite side of the internal space side of the housing and formed corresponding to an outer shape of the housing from the bottom part to the flange part via the side wall part,   
       wherein
 for the punch and the die, side wall surfaces interposing the side wall part of the housing during the press working are each formed in a tapered shape such that the internal space is spread towards a flange part side; and 
 at least part of side wall surfaces of the die has a straight shape extending straight from a tip end in the flange part side in a pressing direction by a prescribed length. 
 
     
     
         4 . The manufacturing apparatus according to  claim 3 , 
       wherein
 opposing surfaces of the punch and the die interposing the flange part of the housing during the press working each has a plane shape parallel to an opening surface of the housing; 
 a protrusion of which the height is lower than a plate-thickness of the flange part is provided on the opposing surface of the punch; and 
 the protrusion is configured to restrain an outer peripheral end part of the flange part during the press working. 
 
     
     
         5 . A housing comprising:
 a side wall part surrounding an internal space;   a bottom part that closes an opening of the side wall part in one side; and   a flange part bent from an opening of the side wall part in the other side towards outside,   
       wherein
 at least part of a bend part extending from the side wall part to the flange part is applied with a crush working, whereby a crush mark is present on at least part of a flange part side of an outer peripheral surface of the side wall part; 
 the crush working is applied using a method for manufacturing a housing including a side wall part surrounding an internal space, a bottom part that closes an opening of the side wall part in one side and a flange part bent from an opening of the side wall part in the other side towards outside, using a press working with a punch and a die for shaping the flange part, comprising steps of: 
 disposing the punch in an internal space side of the housing and the die in an opposite side of the internal space side of the housing; 
 performing, during the press working, a crush working that crushes a bend part formed from the side wall part to the flange part, while drawing at least part of an outer peripheral surface of the side wall part towards a flange part side by using the die, thereby causing a radius of curvature of a portion in the bend part from an inner peripheral surface of the side wall part to the flange part, to be smaller and expanding a flat surface of the flange part in a punch side.