Method of forming a tubular blank into a structural component and die therefor

Abstract

A method of forming an elongated tubular blank into a tubular structural component having a predetermined outer configuration, the method comprising: providing a shape imparting shell formed from a low permeability, rigid material which includes an inner surface defining the predetermined shape, plugging the open ends of the tubular blank, placing the plugged blank into the shell, and forming the tubular blank into the tubular component by inductively heating axial portions of the blank by axially spaced conductors adjacent the shell while or before forcing gas at a high pressure into the plugged blank until the blank conforms to at least a portion of the inner surface of the shell to form the structural component.

1 - 107 . (canceled)  
     
     
         108 . A die set for at least partially forming a blank into a structural component, said die set comprising a first die member, a second die member and a shape imparting shell; said shape imparting shell at least partially formed from a low permeability and rigid material, said shell being at least partially in the form of first and second shell portions; said first die member including a support framework, said support framework including a first compression force transmitting material, said first compression force transmitting material at least partially supporting said first shell portion, said first compression force transmitting material having different physical properties from said first shell portion; said second die member including a support framework, said support framework including a second compression force transmitting material, said second compression force transmitting material at least partially supporting said second shell portion, said second compression force transmitting material having different physical properties from said second shell portion; at least one of said die members being movable to at least partially capture at least a portion of said blank in said shape imparting shell.  
     
     
         109 . The die set as defined in  claim 108 , wherein said first and second compression force transmitting material has a strength and hardness that is different from said first and second shell portions.  
     
     
         110 . The die set as defined in  claim 108 , wherein at least one of said die members includes at least one induction coil.  
     
     
         111 . The die set as defined in  claim 108 , wherein at least one of said die members includes a plurality of induction coils spaced axially along said shell.  
     
     
         112 . The die set as defined in  claim 111 , wherein said plurality of induction coils are nonuniformily spaced axially along said shell.  
     
     
         113 . The die set as defined in  claim 111 , wherein said plurality of induction coils are nonuniformily spaced from at least one of said first and second shell portions.  
     
     
         114 . The die set as defined in  claim 111 , wherein said plurality of induction coils have varying flux field permeabilities.  
     
     
         115 . The die set as defined in  claim 108 , including a quench station to at least partially quench said structural component at least partially along a length of said structural component.  
     
     
         116 . The die set as defined in  claim 108 , including a pressure sensor to sense the pressure of said fluid in said shell and a pressure controller to at least partially control a pressure of fluid being forced into at least a portion of said blank.  
     
     
         117 . The die set as defined in  claim 108 , including at least one heating element positioned adjacent said shell.  
     
     
         118 . The die set as defined in  claim 117 , wherein said heating element includes a plurality of conductors axially spaced along said shell.  
     
     
         119 . The die set as defined in  claim 118 , wherein said plurality of conductors are positioned at different distances from said shell.  
     
     
         120 . The die set as defined in  claim 118 , wherein said plurality of conductors are spaced a different distance from one another.  
     
     
         121 . The die set as defined in  claim 118 , wherein said plurality of conductors have varying flux field permeabilities.  
     
     
         122 . The die set as defined in  claim 108 , including a flux concentrator.  
     
     
         123 . The die set as defined in  claim 108 , including a Faraday shield.  
     
     
         124 . A method of forming an elongated blank into a structural component having a predetermined outer configuration, said method comprising: 
 (a) providing a shape imparting shell at least partially formed from a low permeability, rigid material, said shell being at least partially in the form of first and second shell portions;    (b) providing a first die member having a support framework, said support framework including a first compression force transmitting material which at least partially supports said first shell portion, said first compression force transmitting material having different physical properties from said first shell portion;    c) providing a second die member having a support framework, said support framework including a second compression force transmitting material which at least partially supports said second shell portion, said second compression force transmitting material having different physical properties from said second shell portion;    (d) at least partially placing said blank into at least one of said shell portions;    (e) moving at least one of said die members relative to another of said die members to at least partially capture said blank in said shape imparting shell; and,    (f) at least partially forming said blank into said structural component by heating at least a portion of said blank and forcing a fluid at a high pressure into said blank until said blank at least partially conforms to at least a portion of inner surfaces of said first and second shell portions.    
     
     
         125 . The method as defined in  claim 124 , wherein said fluid is forced into said blank while said blank is heated.  
     
     
         126 . The method as defined in  claim 124 , including the step of heating said blank before forming said blank.  
     
     
         127 . The method as defined in  claim 124 , including sensing a pressure of said fluid used to at least partially expand said blank and at least partially controlling said fluid flow into at least a portion of said blank.  
     
     
         128 . The method as defined in  claim 124 , including the step of at least partially heating said blank before forming said blank.  
     
     
         129 . The method as defined in  claim 124 , including the step of at least partially said blank by induction heating.  
     
     
         130 . The method as defined in  claim 128 , wherein said induction heating is at least partially varied along a length of at least a portion of said blank to modulate the temperature/time pattern along said length.  
     
     
         131 . The method as defined in  claim 128 , wherein said induction heating is at least partially varied by varying a frequency of an alternating current powering spaced conductors.  
     
     
         132 . The method as defined in  claim 128 , wherein said induction heating is at least partially varied by varying a heating time of an alternating current powering said axially spaced conductors.  
     
     
         133 . The method as defined in  claim 128 , wherein said induction heating is at least partially varied by varying the distance said axially spaced conductors are from at least one of said first and second shell portions.  
     
     
         134 . The method as defined in  claim 128 , wherein said induction heating is at least partially varied by varying the spacing between said axially spaced conductors.  
     
     
         135 . The method as defined in  claim 128 , wherein said induction heating is at least partially varied by varying the power of an alternating current powering said axially spaced conductors.  
     
     
         136 . The method as defined in  claim 128 , wherein said induction heating is at least partially varied by varying the permeability of the flux field of selected spaced conductors.  
     
     
         137 . The method as defined in  claim 135 , wherein said flux field is at least partially varied by use of a flux concentrator.  
     
     
         138 . The method as defined in  claim 135 , wherein said flux field is at least partially varied by use of a Faraday shield.  
     
     
         139 . The method as defined in  claim 124 , including the step of transferring said formed structural component to a quench station and at least partially quenching said structural component.  
     
     
         140 . The method as defined in  claim 138 , including the step of at least partially varying said quenching at least partially along said length of said structural component.  
     
     
         141 . The method as defined in  claim 138 , wherein said quench variation is by at least partially varying a flow rate of quenching fluid at least partially along said length of said structural component.  
     
     
         142 . The method as defined in  claim 138 , wherein said quench variation is by at least partially changing location of said quenching operation at least partially along said length of said structural component.  
     
     
         143 . The method as defined in  claim 124 , wherein said fluid is gas.  
     
     
         144 . The method as defined in  claim 124 , wherein said blank is metal.  
     
     
         145 . The method as defined in  claim 124 , wherein said first and second force transmitting material has a strength and hardness that is different from said first and second shell portions.  
     
     
         146 . The method as defined in  claim 144 , wherein said first and second force transmitting material has a strength and hardness that is substantially less than said first and second shell portions.  
     
     
         147 . The method as defined in  claim 124 , including the step of preheating at least a portion of said blank by passing a heating current through at least a portion of said metal blank.  
     
     
         148 . The method as defined in  claim 146 , wherein said heating current is an AC current.