Drum structure for laundry treatment device and method of manufacturing drum

Abstract

A drum structure for laundry treatment device and a method of manufacturing a drum are disclosed. The drum structure for laundry treatment device includes a drum center formed of a metal sheet in a cylindrical shape having a hollow, and the drum center includes a reduced drum portion formed by reducing both ends of the drum center, and a curved portion formed in the reduced drum portion. The drum structure for laundry treatment device and the method of manufacturing a drum do not need to separately manufacture a drum front and a drum rear, do not require separate molds for the manufacture of the drum front and the drum rear, and can reduce the overall manufacturing cost.

What is claimed is: 
     
         1 . A drum structure for laundry treatment device comprising:
 a drum center formed of a metal sheet in a cylindrical shape having a hollow,   wherein the drum center includes:   a reduced drum portion formed by reducing both ends of the drum center; and   a curved portion formed in the reduced drum portion.   
     
     
         2 . The drum structure for laundry treatment device of  claim 1 , wherein the curved portion is continuously formed over an entire circumference of the reduced drum portion. 
     
     
         3 . The drum structure for laundry treatment device of  claim 2 , wherein the curved portion is formed in a concave shape with respect to an outer circumferential surface of the reduced drum portion. 
     
     
         4 . The drum structure for laundry treatment device of  claim 3 , wherein the curved portion is formed such that a plurality of curved portions are spaced apart from each other in parallel. 
     
     
         5 . The drum structure for laundry treatment device of  claim 1 , wherein the drum center is formed by rolling the metal sheet and then welding both ends of the metal sheet,
 wherein a welding line according to the welding of both ends of the metal sheet is formed on the drum center, and   wherein a reinforcement piece is attached to the welding line.   
     
     
         6 . The drum structure for laundry treatment device of  claim 5 , wherein the reinforcement piece is welded to the reduced drum portion in a form perpendicular to the welding line. 
     
     
         7 . A method of manufacturing a drum for laundry treatment device, the method comprising:
 a rolling step of rolling a metal sheet in a hollow cylindrical shape;   a welding step of welding both ends of the metal sheet to form a drum center; and   a molding step of processing a reduced drum portion at both ends of the drum center.   
     
     
         8 . The method of  claim 7 , wherein the molding step comprises processing a curved portion at both ends of the drum center and processing the reduced drum portion. 
     
     
         9 . The method of  claim 8 , wherein the molding step comprises processing the curved portion and the reduced drum portion so that the curved portion is positioned in the reduced drum portion. 
     
     
         10 . The method of  claim 8 , wherein the curved portion supports the processing of the reduced drum portion. 
     
     
         11 . The method of  claim 8 , further comprising, after the molding step, an attaching step of attaching a reinforcement piece to a welding line according to the welding of both ends of the metal sheet. 
     
     
         12 . The method of  claim 11 , wherein the attaching step comprises welding the reinforcement piece to the reduced drum portion in a form perpendicular to the welding line.