Appratus and Method for Manufacturing a Large-Caliber Product Using Hydroforming

Abstract

An apparatus and method for manufacturing using a hydroforming process. The apparatus includes: upper and lower molds; first and second axial punches which are disposed on opposite sides of the steel substance so as to be movable towards each other and which have front surfaces configured so as to be insertable into each other; first and second pressurization cylinders which move the first and second axial punches towards each other and insert them into each other, thus forming a sealing space defined by the first and second axial punches and a pressurization space defined by the steel substance and the first and second axial punches; and a control unit which, through an oil-pressure passage formed in at least one of the first and second axial punches, supplies fluid into the pressurization space to pressurize the steel substance, thus forming the large caliber product.

1 . An apparatus for manufacturing a large-caliber product using a hydroforming process, comprising:
 upper and lower molds into which a tubular steel substance having a large caliber is seated;   a first axial punch and a second axial punch disposed on opposite sides of the steel substance so as to be movable towards each other, the first and second axial punches having front surfaces configured so as to be insertable into each other;   a first pressurization cylinder and a second pressurization cylinder respectively moving the first axial punch and the second axial punch towards each other and inserting the first and second axial punches into each other, thus forming a sealing space defined by the first and second axial punches and a pressurization space defined by an inner surface of the steel substance and the first and second axial punches; and   a hydroforming control unit supplying fluid into the pressurization space through an oil-pressure passage formed in at least one of the first and second axial punches so as to pressurize the inner surface of the steel substance, thus forming the large caliber product.   
     
     
         2 . The apparatus for manufacturing a large-caliber product using a hydroforming process according to  claim 1 , wherein sealing members are respectively provided on portions of the first and second axial punches that form the sealing space. 
     
     
         3 . The apparatus for manufacturing a large-caliber product using a hydroforming process according to  claim 1 , wherein an air hole is formed in at least one of the first and second axial punches so that air can be discharged out of the sealing space through the air hole. 
     
     
         4 . The apparatus for manufacturing a large-caliber product using a hydroforming process according to  claim 1 , wherein the oil-pressure passage directly communicates with the pressurization space. 
     
     
         5 . The apparatus for manufacturing a large-caliber product using a hydroforming process according to  claim 1 , wherein stepped portions are respectively provided on the first and second axial punches to seal opposite side ends of the steel substance. 
     
     
         6 . A method for manufacturing a large-caliber product using a hydroforming process, comprising:
 a hydroforming preparation operation of seating a steel substance having a large caliber onto a lower mold and moving an upper mold downwards, thus closing an entirety of the upper and lower molds;   an axial punch setting operation of moving a first axial punch and a second axial punch towards each other from opposite sides of the steel substance and inserting the first and second axial punches into each other, thus forming a sealing space defined by the first and second axial punches, and a pressurization space defined by an inner surface of the steel substance and the first and second axial punches; and   a hydroforming operation of supplying fluid into the pressurization space through at least one of the first and second axial punches and pressurizing the inner surface of the steel substance, thus forming the large-caliber product.   
     
     
         7 . The method for manufacturing a large-caliber product using a hydroforming process according to  claim 6 , wherein the axial punch setting operation comprises discharging air out of the sealing space by moving the first and second axial punches towards each other. 
     
     
         8 . The method for manufacturing a large-caliber product using a hydroforming process according to  claim 6 , wherein the hydroforming operation comprises sealing opposite side ends of the steel substance using the first axial punch and the second axial punch.