Bending machine and bending method

Abstract

A bending machine includes hydraulic cylinders capable of adjusting an inclination state, eccentric shaft units, and a control device. The control device sets an inclination state of the upper table and also sets a curved state of the lower table to conform to the inclination state of the upper table in order to carry out partial bending to pressurize a limited pressurized range compared to a pressurized range in which a workpiece is pressurized by using entire areas of an upper tool and a lower tool in a lateral direction. The control device changes a combination of the inclination state of the upper table and the curved state of the lower table and repeats the partial bending while causing a transition of the limited pressurized range in order to carry out entire area bending to pressurize the workpiece over an entire area in the lateral direction.

1 . A bending machine including a movable table to which a first tool is attached along a lateral direction, and a fixed table arranged to be opposed to the movable table in a vertical direction and to which a second tool is attached along the lateral direction, the movable table being moved in the vertical direction to pressurize a workpiece between the first tool and the second tool in order to carry out bending of the workpiece, the bending machine comprising:
 an elevating mechanism configured to move the movable table in the vertical direction and capable of adjusting an inclination state showing an inclination to left and right of the movable table;   a crowning mechanism configured to curve a part of the fixed table; and   a control device configured to control the elevating mechanism and the crowning mechanism, wherein   the control device sets the inclination state of the movable table and also sets a curved state of the fixed table to conform to the inclination state of the movable table in order in order to carry out partial bending to pressurize a limited pressurized range compared to a pressurized range in which the workpiece is pressurized by using entire areas of the first tool and the second tool in the lateral direction, and   the control device changes a combination of the inclination state of the movable table and the curved state of the fixed table and repeats the partial bending while causing a transition of the limited pressurized range in order to carry out entire area bending to pressurize the workpiece over an entire area in the lateral direction.   
     
     
         2 . The bending machine according to  claim 1 , wherein the control device repeats the entire area bending a plurality of times to bend the workpiece step by step to a target bending angle. 
     
     
         3 . The bending machine according to  claim 1 , wherein
 the elevating mechanism can move the movable table in a range from a top dead center at which the movable table is separated from the fixed table by a predetermined distance to a bottom dead center at which the movable table comes closest to the fixed table, and   the control device sets the inclination state of the movable table before the movable table reaches the bottom dead center when the partial bending is carried out.   
     
     
         4 . The bending machine according to  claim 3 , wherein, after the partial bending, the control device moves the movable table toward the top dead center within a range in which the first tool and the workpiece are in contact with each other by spring back of the workpiece, and then changes a combination of the inclination state of the movable table and the curved state of the fixed table. 
     
     
         5 . The bending machine according to  claim 4 , wherein the control device moves the movable table toward the top dead center while maintaining the inclination state thereof when the workpiece is pressurized in the limited pressurized range. 
     
     
         6 . The bending machine according to  claim 1 , wherein the control device curves a left side of the fixed table upward when the movable table is in an inclination state in which a left side of the movable table is closer to the fixed table than a right side of the movable table. 
     
     
         7 . The bending machine according to  claim 1 , wherein the control device curves a right side of the fixed table upward when the movable table is in an inclination state in which a right side of the movable table is closer to the fixed table than a left side of the movable table. 
     
     
         8 . The bending machine according to  claim 1 , wherein the control device curves a center of the fixed table upward when the movable table is in an inclination state in which the left and right of the movable table is horizontal. 
     
     
         9 . The bending machine according to  claim 1 , wherein
 the elevating mechanism includes left and right elevating units provided at left and right ends of the movable table and capable of being controlled independently of each other, and   the crowning mechanism includes left and right crowning units provided symmetrically with respect to a center position of the fixed table in the lateral direction and capable of being controlled independently of each other.   
     
     
         10 . The bending machine according to  claim 9 , wherein when the workpiece is pressurized after being divided into three pressurized ranges of a left side, a center, and a right side, the control device corrects outputs of the left and right elevating units and outputs of the left and right crowning units based on bending angles obtained at four angle measurement points positioned at boundaries of the respective pressurized ranges. 
     
     
         11 . A bending machine including a movable table to which a first tool is attached along a lateral direction, and a fixed table arranged to be opposed to the movable table in a vertical direction and to which a second tool is attached along the lateral direction, the movable table being moved in the vertical direction to pressurize a workpiece between the first tool and the second tool in order to carry out bending of the workpiece, the bending machine comprising:
 an elevating mechanism configured to move the movable table in the vertical direction;   an inclination mechanism capable of adjusting an inclination state showing an inclination to left and right of the fixed table;   a crowning mechanism configured to curve a part of the movable table; and   a control device configured to control the elevating mechanism, the inclination mechanism, and the crowning mechanism, wherein   the control device sets the inclination state of the fixed table and also sets a curved state of the movable table to conform to the inclination state of the fixed table in order to carry out partial bending to pressurize a limited pressurized range compared to a pressurized range when the workpiece is pressurized by using entire areas of the first tool and the second tool in the lateral direction, and   the control device changes a combination of the inclination state of the fixed table and the curved state of the movable table and repeats the partial bending while causing a transition of the limited pressurized range in order to carry out entire area bending to pressurize the workpiece over an entire area in the lateral direction.   
     
     
         12 . A bending method of carrying out bending of a workpiece in which a bending machine including a movable table to which a first tool is attached along a lateral direction and a fixed table arranged to be opposed to the movable table in a vertical direction and to which a second tool is attached along the lateral direction, carries out bending of a workpiece by moving the movable table in the vertical direction to pressurize the workpiece between the first tool and the second tool, the bending method comprising:
 setting an inclination state of the movable table; setting a curved state of the fixed table so as to conform to the inclination state of the movable table;   carrying out partial bending to pressurize a limited pressurized range compared to a pressurized range when the workpiece is pressurized by using entire areas of the first tool and the second tool in the lateral direction; and   carrying out entire area bending to pressurize the workpiece over an entire area in the lateral direction by changing a combination of the inclination state of the movable table and the curved state of the fixed table and repeating the partial bending while causing a transition of the limited pressurized range.