Aluminum extruded raw pipe, method of manufacturing the same, aluminum pipe for photosensitive drums, and method of manufacturing the same

Abstract

A method of manufacturing an aluminum extruded raw pipe capable of suppressing the surface roughness of the extruded raw pipe and a method of manufacturing an aluminum pipe to be used as a photosensitive drum excellent in surface quality are provided. In a method of manufacturing an aluminum extruded raw pipe by extruding an aluminum billet 1 , as the billet 1 , a billet whose maximum value of the thickness T of the solidified shell layer 2 of the external peripheral surface is 13 mm or less is used. By subjecting the obtained aluminum extruded raw pipe to a drawing process or an ironing process, an aluminum pipe equipped with surface quality preferable to a photosensitive drum can be obtained.

1 . A method of manufacturing an aluminum extruded raw pipe, including the step of: 
 extruding an aluminum billet having a solidified shell layer formed at an external peripheral surface thereof, the solidified shell layer having the maximum thickness of 13 mm or less.    
   
   
       2 . The method of manufacturing an aluminum extruded raw pipe as recited in  claim 1 , wherein the maximum thickness of the solidified shell layer is 11 mm or less.  
   
   
       3 . The method of manufacturing an aluminum extruded raw pipe as recited in  claim 1  or  2 , wherein the billet is made of A3003 aluminum alloy.  
   
   
       4 . A method of manufacturing an aluminum billet in accordance with a float casting method, including the step of: 
 casting an aluminum billet at a casting rate of 95 mm/minute or less.    
   
   
       5 . The method of manufacturing an aluminum billet as recited in  claim 4 , wherein the casting is performed at a casting rate of 85 to 90 mm/minute.  
   
   
       6 . A method of manufacturing an aluminum billet in accordance with a float casting method, including the step of: 
 casting an aluminum billet while keeping a distance from a lowermost portion of a mold to an upper surface position of a molten aluminum to be 40 mm or less.    
   
   
       7 . The method of manufacturing the aluminum billet as recited in  claim 6 , wherein the casting is performed while keeping the distance from the lowermost portion of the mold to the upper surface position of the molten aluminum to be 30 to 35 mm.  
   
   
       8 . A method of manufacturing an aluminum billet in accordance with a float casting method, including the step of: 
 casting an aluminum billet at a casting rate of 95 mm/minute or less while keeping a distance from a lowermost portion of a mold to an upper surface position of a molten aluminum to be 40 mm or less.    
   
   
       9 . The method of manufacturing an aluminum billet as recited in any one of  claims 4  to  8 , wherein an A3003 aluminum alloy is used as a molten aluminum.  
   
   
       10 . A billet manufactured by the method as recited in any one of  claims 4  to  9 .  
   
   
       11 . A method of manufacturing an aluminum extruded raw pipe, including the step of: 
 extruding the billet manufactured by the method as recited in any one of  claims 4  to  9 .    
   
   
       12 . A method of manufacturing an aluminum extruded raw pipe as recited in any one of claims  1 ,  2 ,  3  and  11 , wherein the aluminum extruded raw pipe is an aluminum extruded raw pipe to be used as a photosensitive drum.  
   
   
       13 . An aluminum extruded raw pipe manufactured by the method as recited in any one of claims  1 ,  2 ,  3  and  11 .  
   
   
       14 . An aluminum extruded raw pipe to be used as a photosensitive drum, wherein the aluminum extruded raw pipe is manufactured by the method as recited in any one of claims  1 ,  2 ,  3  and  11 .  
   
   
       15 . A method of manufacturing an aluminum pipe to be used as a photosensitive drum, including the step of: 
 subjecting the aluminum extruded raw pipe manufactured by the method as recited in any one of claims  1 ,  2 ,  3  and  11  to a drawing process.    
   
   
       16 . A method of manufacturing an aluminum pipe to be used as a photosensitive drum, 
 subjecting the aluminum extruded raw pipe manufactured by the manufacturing method as recited in any one of claims  1 ,  2 ,  3  and  11  to an ironing process.    
   
   
       17 . An aluminum pipe to be used as a photosensitive drum, wherein the aluminum pipe is manufactured by the method as recited in  claim 15  or  16 .