Method and Apparatus for Forming Materials with Low Ductility

Abstract

The invention provides an apparatus and a method of forming a material of low ductility including providing a first sheet made from a material of low ductility, providing an integrated forming device comprising a heat source and a forming element, and moving the forming element relative to the first sheet along a forming direction while simultaneously heating a localized portion of the first sheet along the forming direction at a substantially constant predetermined distance in front of the forming element. The predetermined distance is selected so as to yield a predetermined temperature to achieve a predetermined ductility at the localized portion of the first sheet when the forming element reaches the localized portion of the first sheet.

What is claimed is: 
     
         1 . A method of forming a formed product from a material of low ductility, comprising:
 providing a first sheet made from a material of low ductility;   providing an integrated forming device comprising:
 a laser source; and 
 a roll forming element comprising at least one roller; and 
   simultaneously performing the following:
 forming the first sheet, comprising moving the roll forming element relative to the first sheet along a forming direction, the roll forming element being arranged relative to the first sheet to form a bending location in advance of the roll forming element, so as to fold an edge portion of the first sheet back upon itself during moving along the forming direction, thereby hemming the first sheet; and 
 using the laser source, irradiating with a laser beam a localized portion of the first sheet along the forming direction at a substantially constant predetermined distance immediately in front of the forming element and within the bending location, thereby heating the localized portion of the first sheet at the substantially constant predetermined distance in front of the forming element and introducing heat into the bending location simultaneously with the forming step, wherein the predetermined distance is selected so as to yield a predetermined forming temperature to achieve a predetermined ductility at the localized portion of the first sheet when the roll forming element reaches the localized portion of the first sheet, and 
 further comprising:
 selecting the forming temperature and a number of forming steps in dependence upon a complexity of a forming shape of the formed product; 
 
   wherein forming the first sheet comprises:   heating the localized portion of the first sheet to a first forming temperature and performing a first number of forming steps when the complexity of the forming shape is below a predetermined threshold, and   heating the localized portion of the first sheet to a second forming temperature and performing a second number of forming steps when the complexity of the forming shape is above a predetermined threshold,   wherein the second forming temperature is lower than the first forming temperature and the second number of steps is greater than the first number of steps.   
     
     
         2 . A method as defined in  claim 1  wherein the material of low ductility is at least one of aluminum, aluminum alloy, magnesium, and magnesium alloy. 
     
     
         3 . A method as defined in  claim 1  wherein the step of heating is performed at a temperature in a range between about 150° C. to about 500° C. 
     
     
         4 . A method as defined in  claim 1  further comprising the step of providing a programmable logic control for retrieving a predetermined forming temperature for the material of low ductility and an incident angle of the laser beam on the localized portion of the first sheet. 
     
     
         5 . A method as defined in  claim 1  comprising:
 prior to simultaneously moving the roll forming element and irradiating with a laser beam, performing the following: 
 providing a second sheet adjacent to the first sheet; and 
 securing the first sheet relative to the second sheet, said second sheet having a peripheral edge; 
 wherein moving the roll forming element comprises moving the roll forming element relative to the first and second sheets so as to fold the edge portion of the first sheet over the peripheral edge of the second sheet. 
 
     
     
         6 . A method as defined in  claim 5  wherein the predetermined distance is selected so as to yield a predetermined temperature to achieve a predetermined ductility at the localized portion when the roll forming element reaches the localized portion. 
     
     
         7 . A method as defined in  claim 5  wherein the localized portion is heated to a temperature in a range from about 150° C. to about 500° C. by means of the energy beam. 
     
     
         8 . A method as defined in  claim 1 , wherein the roll forming element comprises at least two rollers. 
     
     
         9 . A method as defined in  claim 1 , wherein the laser beam has a large spot at the predetermined forming area. 
     
     
         10 . A method as defined in  claim 9 , wherein the laser beam is one of a defocused beam and an enlarged beam produced by beam shaping optical components. 
     
     
         11 . A method as defined in  claim 9 , wherein the laser beam is a raw beam generated directly by a laser source. 
     
     
         12 . A method as defined in  claim 1 , wherein the laser beam is a round beam or a rectangular beam. 
     
     
         13 . A method as defined in  claim 1 , wherein the incident angle of the laser beam is varied with the folding angle of the at least one roller. 
     
     
         14 . An apparatus for forming a material of low ductility comprising an integrated forming device including a forming element and an energy source, wherein the forming element and the energy source advance simultaneously relative to the material of low ductility. 
     
     
         15 . An apparatus as defined in  claim 14  wherein the forming device comprises a roll forming element. 
     
     
         16 . An apparatus as defined in  claim 14  wherein the energy source is one of a laser source, an infrared source, and a source of inductive heat. 
     
     
         17 . An apparatus as defined in  claim 14  comprising:
 a retaining device for positioning a panel assembly relative to the forming element, the panel assembly including an outer panel formed from the material of low ductility and an inner panel, 
 wherein the forming element is a roller element; and 
 wherein the energy source is a heat source moving in unison with the roller element, the heat source is disposed to emit an energy beam onto a localized portion of the panel assembly at a substantially constant predetermined distance in front of the roller element. 
 
     
     
         18 . An apparatus as defined in  claim 17  wherein the predetermined distance is selected so as to yield a predetermined temperature to achieve a predetermined ductility at the localized portion of the panel assembly when the roller element reaches the localized portion of the panel assembly. 
     
     
         19 . An apparatus as defined in  claim 17  wherein the heat source is one of a laser source, an infrared source and a source of inductive heat. 
     
     
         20 . A roller hemming apparatus as defined in  claim 19  wherein the energy beam is one of a laser beam and an infrared beam.