Outer panel for pillar of vehicle, and method and rolling apparatus for manufacturing the same

Abstract

An outer panel for a pillar of a vehicle includes a central portion, flanges at opposite sides thereof for bonding to an inner panel, and opposite side portions between the central portion and the flange portions in a transverse sectional shape, wherein each of the side portions located at opposite sides of the central portion has a collision energy absorbing section having a thickness that is smaller than that of the central portion.

1 - 5 . (canceled) 
     
     
         6 . A rolling apparatus for generating a thickness difference by tailor-rolled-blank (TRB) rolling a steel plate that is a material of an outer panel to manufacture the outer panel having a collision energy absorbing section in which side portions located at opposite sides of a central portion have reduced thicknesses as compared with the central portion, comprising:
 two rollers disposed in a direction parallel to a lengthwise direction of the outer panel manufactured of the steel plate such that the steel plate passes between the two rolling rollers by making a widthwise direction of the steel plate passing through the upper rolling roller and the lower rolling roller the same as a lengthwise direction of the outer panel, and one of the upper rolling roller and the lower rolling roller is a roller having a sectional shape in which a protrusion is formed at one side of a circular cross-section.   
     
     
         7 . The rolling apparatus of  claim 6 , wherein the other of the upper rolling roller and the lower rolling roller is a roller having a circular cross-section. 
     
     
         8 . The rolling apparatus of  claim 7 , wherein the upper rolling roller is a roller having a sectional shape in which a protrusion is formed at one side of the circular shape and the lower rolling roller is a roller having a circular cross-section. 
     
     
         9 . A method of manufacturing an outer panel in which side portions located at opposite sides of a central portion have collision energy absorbing sections in which thicknesses thereof are smaller than a thickness of the central portion, the method comprising:
 a rolling step of TRB rolling a steel plate that is a material of the outer panel to generate a thickness change of the steel plate along a rolling direction; and   a processing step of pressing and cutting the steel plate having undergone the rolling step to produce a shape of the outer panel,   wherein in the rolling step, a thickness difference of parts of the steel plate that are to become a central portion and side portions along the rolling direction by passing the steel plate between the two rolling rollers such that a widthwise direction of the steel plate passing between the upper rolling roller and the lower rolling roller is the same as a lengthwise direction of the outer panel.   
     
     
         10 . The method of  claim 9 , wherein each of the side portions has a collision energy absorbing section in which a thickness thereof gradually decreases and then increases again in a transverse sectional shape thereof. 
     
     
         11 . The method of  claim 9 , wherein in the transverse sectional shape, a thickest portion is formed at the central portion, and thinnest portion in which thicknesses of the outer panel gradually decrease from the thickest portion to opposite sides such that the thinnest portion is formed at the side portions. 
     
     
         12 . The method of  claim 12 , wherein sectional thicknesses of the outer panel gradually increase as they go from the thinnest portions to opposing flanges, and thicknesses of the flanges are set to be small to be within a set ratio as compared the thickest thickness of the central portion. 
     
     
         13 . The outer panel of  claim 11 , wherein the thickest portion of the central portion and the thinnest portions of the side portions have thickness maintaining sections having the same thicknesses. 
     
     
         14 . The method of  claim 11 , wherein a thickness change profile of the steel plate is W-shaped along the central portion, the side portions, and the flange portions of the opposite ends of the panel along the rolling direction in the rolling step. 
     
     
         15 . The method of  claim 9 , wherein one of the upper rolling roller and the lower rolling roller is a roller having a sectional shape in which a protrusion is formed at one side of a circular cross-section, and the other roller is a roller having a circular cross-section.