Hot forming tool with infrared light source

Abstract

The method includes the step of preparing a die assembly and proceeds with the step of heating a blank that is made of metal. The method continues with the step of inserting the heated blank into the die assembly. The method proceeds with the step of closing the die assembly to deform the blank into a structural component. With the die assembly closed, the method continues with the step of simultaneously cooling at least one first portion of the structural component that is in contact with the first and second forming surfaces and directing infrared light directly onto at least one second portion of the structural component through the at least one opening to maintain the at least one second portion at an elevated temperature compared to the at least one first portion.

What is claimed is: 
     
         1 . A method of making a structural component that has tailored properties, comprising the steps of:
 preparing a die assembly which includes a first die with a first forming surface and a second die with a second forming surface and wherein at least one of the first and second dies presents at least one opening which extends to a respective one of the first and second forming surfaces;   heating a blank that is made of metal;   inserting the heated blank into the die assembly between the first and second forming surfaces;   closing the die assembly to deform the blank into a structural component; and   with the die assembly closed, simultaneously cooling at least one first portion of the structural component that is in contact with the first and second forming surfaces and directing infrared light directly onto at least one second portion of the structural component through the at least one opening to maintain the at least one second portion of the structural component at an elevated temperature compared to the at least one first portion.   
     
     
         2 . The method as set forth in  claim 1  further including the steps of opening the die assembly and removing the structural component from the die assembly and wherein the at least one second portion of the structural component is at a higher temperature than the at least one first portion of the structural component when the structural component is removed from the die assembly. 
     
     
         3 . The method as set forth in  claim 2  wherein the heated blank is above 650 degrees Celsius before the step of closing the die assembly. 
     
     
         4 . The method as set forth in  claim 3  wherein the at least one first portion of the structural component has a temperature that is less than 200 degrees Celsius and the at least one second portion of the structural component has a temperature that is greater than  300  Celsius when the structural component is removed from the die assembly. 
     
     
         5 . The method as set forth in  claim 4  wherein the metal of the at least one first portion of the structural component is at least substantially entirely martensite after the structural component is removed from the die assembly. 
     
     
         6 . The method as set forth in  claim 2  wherein the step of directing infrared light directly onto the at least one second portion of the structural component occurs for less than an entire time that the die assembly is closed. 
     
     
         7 . The method as set forth in  claim 1  wherein each of the first and second forming surfaces is provided with at least one opening and wherein the openings in the first and second forming surfaces are aligned with one another. 
     
     
         8 . The method as set forth in  claim 1  wherein the first and second dies have openings that are aligned with one another and wherein the step of directing light directly at the at least one second portion of the structural component is further defined as directing light directly at the second portion through both of the aligned openings in the first and second dies. 
     
     
         9 . The method as set forth in  claim 1  wherein the blank is made of 22MnB5 steel. 
     
     
         10 . The method as set forth in  claim 1  wherein the step of closing the die assembly is further defined as moving one of the first and second dies towards the other of the first and second dies to sandwich the blank between the first and second forming surfaces. 
     
     
         11 . A die assembly for making a structural component, comprising:
 a first die that has a first forming surface and a second die that has a second forming surface and wherein at least one of said first and second dies is movable relative to the other of said first and second dies to open and close said die assembly;   said first and second dies having cooling channels for conveying a coolant through said first and second dies to cool the structural component;   at least one of said first and second dies having at least one opening that extends to the respective forming surface; and   at least one infrared lamp disposed in said at least one opening for directing infrared light directly onto the structural component when said die assembly is closed.   
     
     
         12 . The die assembly as set forth in  claim 11  wherein each of said first and second dies has at least one opening and wherein said openings in said first and second dies are aligned with one another. 
     
     
         13 . The die assembly as set forth in  claim 12  wherein said at least one infrared lamp is disposed in said opening of one of said first and second dies and said aligned opening in the other of said first and second dies is free of infrared lamps. 
     
     
         14 . The die assembly as set forth in  claim 12  wherein infrared lamps are disposed in both of said aligned openings in said first and second dies. 
     
     
         15 . The die assembly as set forth in  claim 11  wherein each of said first and second dies has a plurality of said openings. 
     
     
         16 . The method as set forth in  claim 1  wherein during the step of closing the die assembly to deform the blank into a structural component, the first and second forming surfaces directly contact the blank. 
     
     
         17 . The method as set forth in  claim 1  wherein the first and second dies have openings that are aligned with one another and wherein the infrared light is directed onto the at least one second portion of the structural portion through only either the opening of the first die or the opening of the second die.