Method for bending metal material, bending machine, bending-equipment line, and bent product

Abstract

A method, bending machine, and bending equipment line for bending a workpiece involves successively or continuously feeding the workpiece held by a supporting unit from an upstream side of the supporting unit, and performing bending at a downstream side of the supporting unit. The bending method includes: supporting the metal material with a movable roller die; controlling the position of the movable roller die and/or the moving speed of the metal material; heating the metal material in a temperature range in which the heated portion can be plastically deformed and in a temperature range in which quenching can be performed, by using a heating unit that is provided around the outer circumference of the metal material, to apply a bending moment to the heated portion; and rapidly cooling the heated portion, by using a cooling unit that is provided around the outer circumference of the metal material.

1 . A method for bending a metal material in which, in a bending process, while successively or continuously feeding the metal material held by a supporting unit from an upstream side of the supporting unit, the bending is performed for the metal material at a downstream side of the supporting unit, comprising: 
 clamping the metal material with a movable roller die that is provided at the downstream side of the supporting unit;    controlling the position of the movable roller die and/or the moving speed of the metal material;    heating the metal material in a temperature range in a temperature range in which quenching can be performed, by using a heating unit that is provided around the outer circumference of the metal material at an entrance side of the movable roller die, to apply a bending moment to the heated portion; and    rapidly cooling down the heated portion by using a cooling unit that is provided around the outer circumference of the metal material at the entrance side of the movable roller die.    
   
   
       2 . The method for bending a metal material according to  claim 1 , 
 wherein the movable roller die includes at least one of a shift mechanism for moving the movable roller die in a vertical direction, a shift mechanism for moving the movable roller die in a horizontal direction, a tilt mechanism for inclining the movable roller die in a vertical direction, and a tilt mechanism for inclining the movable roller die in a horizontal direction.    
   
   
       3 . The method for bending a metal material according to  claim 2 , 
 wherein the movable roller die further includes a moving mechanism for moving the movable roller die in a forward or backward direction.    
   
   
       4 . The method for bending a metal material according to  claim 2 , 
 wherein the heating unit and/or the cooling unit include at least one of a shift mechanism for moving the unit in a vertical direction, a shift mechanism for moving the unit in a horizontal direction, a tilt mechanism for inclining the unit in a vertical direction, and a tilt mechanism for inclining the unit in a horizontal direction.    
   
   
       5 . The method for bending a metal material according to  claim 4 , 
 wherein the heating unit and/or the cooling unit further include a moving mechanism for moving the unit in a forward or backward direction.    
   
   
       6 . The method for bending a metal material according to  claim 1 , 
 wherein the movable roller die includes a rotational mechanism for rotating the movable roller die in a circumferential direction.    
   
   
       7 . The method for bending a metal material according to  claim 1 , 
 wherein a feeding apparatus is provided at the upstream side of the metal material, and includes a mechanism that holds and rotates a workpiece in a circumferential direction.    
   
   
       8 . The method for bending a metal material according to  claim 7 , 
 wherein the supporting unit includes a rotational mechanism for rotating the supporting unit in a circumferential direction, and rotates in the circumferential direction in synchronization with the rotation by the feeding apparatus.    
   
   
       9 . The method for bending a metal material according to  claim 1 , 
 wherein the movable roller die includes a driving mechanism that drives rollers, and drives and rotates the rollers according to the feed amount of the metal material fed by the feeding apparatus.    
   
   
       10 . The method for bending a metal material according to  claim 1 , 
 wherein the movable roller die includes two rollers, three rollers, or four rollers.    
   
   
       11 . The method for bending a metal material according to  claim 1 , 
 wherein the metal material subjected to bending is a closed cross-section member, an open cross-section member, an irregular cross-section member, or a rod-shaped member that has any of various shapes in sectional view.    
   
   
       12 . The method for bending a metal material according to  claim 1 , 
 wherein one or more preheating units are provided at the upstream side of the heating unit to perform plural-stage heating or preferential heating on the metal material.    
   
   
       13 . The method for bending a metal material according to  claim 1 , 
 wherein a mandrel, serving as the cooling unit, is inserted into the metal material, and a cooling medium is supplied into the mandrel.    
   
   
       14 . The method for bending a metal material according to  claim 13 , 
 wherein the cooling medium supplied from the cooling unit contains water as a primary component and a rust-preventative agent and/or a quenching agent.    
   
   
       15 . The method for bending a metal material according to  claim 1 , 
 wherein a lubricant and/or a cooling fluid are supplied to the movable roller die.    
   
   
       16 . The method for bending a metal material according to  claim 1 , 
 wherein an articulated robot having one or more joints that each can rotate on its axis is provided, and    the articulated robot performs the operation of at least one of the shift mechanism, the tilt mechanism, and the moving mechanism for the movable roller die, and the heating unit and/or the cooling unit.    
   
   
       17 . A bending machine in which a supporting unit to support a workpiece and a feeding apparatus to successively or continuously feed the workpiece from an upstream side are provided, and a bending operation is performed at a downstream side of the supporting unit in association with a feed amount of the workpiece by the feeding apparatus, comprising: 
 a movable roller die that is provided at the downstream side of the supporting unit, supports the metal material, and controls the supporting position and/or the moving speed of the metal material;    a heating unit that is provided around the outer circumference of the metal material at an entrance side of the movable roller die, and heats the metal material in a temperature range in which the heated portion of the metal material can be plastically deformed and in a temperature range in which quenching can be performed; and    a cooling unit that is provided around the outer circumference of the metal material at an entrance side of the movable roller die, and rapidly cools down the heated portion of the metal material to which a bending moment is applied.    
   
   
       18 . The bending machine according to  claim 17 , 
 wherein the movable roller die includes at least one of a shift mechanism for moving the movable roller die in a vertical direction, a shift mechanism for moving the movable roller die in a horizontal direction, a tilt mechanism for inclining the movable roller die in a vertical direction, and a tilt mechanism for inclining the movable roller die in a horizontal direction.    
   
   
       19 . The bending machine according to  claim 17 , 
 wherein the movable roller die further includes a moving mechanism for moving the movable roller die in a forward or backward direction.    
   
   
       20 . The bending machine according to  claim 17 , 
 wherein the heating unit and/or the cooling unit include at least one of a shift mechanism for moving the unit in a vertical direction, a shift mechanism for moving the unit in a horizontal direction, a tilt mechanism for inclining the unit in a vertical direction, and a tilt mechanism for inclining the unit in a horizontal direction.    
   
   
       21 . The bending machine according to  claim 20 , 
 wherein the heating unit and/or the cooling unit further include a moving mechanism for moving the unit in a forward or backward direction.    
   
   
       22 . The bending machine according to  claim 17 , 
 wherein the movable roller die includes a rotational mechanism for rotating the movable roller die in a circumferential direction.    
   
   
       23 . The bending machine according to  claim 17 , 
 wherein the feeding apparatus includes a mechanism that holds and rotates a workpiece in the circumferential direction.    
   
   
       24 . The bending machine according to  claim 23 , 
 wherein the supporting unit includes a rotational mechanism that rotates the supporting unit in a circumferential direction in synchronization with the rotation by the pushing apparatus.    
   
   
       25 . The bending machine according to  claim 17 , 
 wherein the movable roller die includes a driving mechanism that drives and rotates the rollers according to the amount of the metal material extruded by the pushing apparatus.    
   
   
       26 . The bending machine according to  claim 17 , 
 wherein the movable roller die includes two rollers, three rollers, or four rollers.    
   
   
       27 . The bending machine according to  claim 17 , 
 wherein the metal material subjected to bending is a closed cross-section member, an open cross-section member, an irregular cross-section member, or a rod-shaped member that has any of various shapes in sectional view.    
   
   
       28 . The bending machine according to  claim 17 , further comprising: 
 a preheating unit that is provided at the upstream side of the heating unit to perform plural-stage heating or preferential heating on the metal material.    
   
   
       29 . The bending machine according to  claim 17 , 
 wherein a mandrel, serving as the cooling unit, is inserted into the metal material, and a cooling medium is supplied into the mandrel.    
   
   
       30 . The bending machine according to  claim 29 , 
 wherein the cooling medium supplied from the cooling unit contains water as a primary component and a rust-preventative agent and/or a quenching agent.    
   
   
       31 . The bending machine according to  claim 17 , further comprising: 
 a lubrication unit that supplies a lubricant and/or a cooling fluid to the movable roller die.    
   
   
       32 . The bending machine according to  claim 17 , further comprising: 
 an articulated robot that has one or more joints that each can rotate on its axis, and performs the operation of at least one of the shift mechanism, the tilt mechanism, and the moving mechanism for the movable roller die, and the heating unit and/or the cooling unit.    
   
   
       33 . A bending-equipment line comprising: 
 an electric resistance welded steel tube manufacturing line that includes: an uncoiler that continuously unrolls into a strip-shaped steel sheet; a forming machine that forms the unrolled strip-shaped steel sheet into steel tube having a predetermined shape in sectional view; a welding machine that welds opposite edges of the strip-shaped steel sheets to each other to form continuous tube; and a post-processing machine that performs a weld bead cutting operation, and, if necessary, a post-annealing operation or a sizing operation; and    the bending machine according to  claim 17  that is sequentially arranged at the exit side of the electric resistance welded steel tube manufacturing line.    
   
   
       34 . A bending-equipment line comprising: 
 a roll forming line that includes: an uncoiler that continuously unrolls into a strip-shaped steel sheet; and a forming machine that forms the unrolled strip-shaped steel sheet into a predetermined shape in sectional view; and    the bending machine according to  claim 17  that is sequentially arranged at the exit side of the roll forming line.    
   
   
       35 . A bent product that is subjected to a thermomechanical treatment by virtue of the method for bending a metal material according to  claim 1 , and has a tensile strength of 900 MPa or more.  
   
   
       36 . A bent product that is subjected to a thermomechanical treatment by virtue of using the metal material bending machine according to  claim 17 , and has a tensile strength of 900 MPa or more.