Bending machine for creating bends to the left and right

Abstract

A machine and method for bending tubes of large diameter in different bending directions, wherein a tube ( 10 ) is guided in the axial direction through an annular inductive heating device ( 7 ); the tube ( 10 ) is secured by a bending lock ( 4 ) at the end ( 11 ) thereof intended to be bent; at least one bending arm ( 2 ), which is mounted rotatably about a vertical axis of rotation ( 8 ), is located at the part of the bending machine that is disposed in the advancing direction of the tube ( 10 ); the bending lock ( 4 ) is indirectly connected to the bending arm ( 2 ); the bending lock ( 4 ) has a force transmission device between the receiving device for tubes and the bending arm ( 2 ); and the force transmission device is connected to the bending arm ( 2 ).

1 . A device for bending tubes with large diameters in different bending directions, wherein
 a tube is guided in the axial direction through an inductively acting heating device that surrounds this tube in an annular fashion,   the tube is secured with a bending lock at the end that is to bent,   at least one bending arm that is supported in a rotating fashion around its vertical rotational axis is located at the part of the device for bending and which is situated in the feeding direction of the tube,   the bending lock is connected indirectly to the bending arm,   the bending lock exhibits a force transfer device between the take-up device for tubes and the bending arm,   the force transfer device is connected to the bending arm in an adjustable manner such that the distances between the center axis of the take-up device for tubes and the vertical rotational axis can be selected between a minimum and a maximum distance, which allows for setting a range between a maximum and minimum bending radius,   
       the improvement wherein:
 the device includes at least one additional bending lock with one additional bending arm, a take-up device for tubes and a force transfer device for bending forces from the take-up device to the additional bending arm, 
 the direction of rotation of the additional bending arm is opposite to the direction of rotation of the first bending arm, and 
 each of the two bending arms is movable parallel to each other and perpendicular to the feeding direction of the tubes to be bent. 
 
     
     
         2 . A method for carrying our several bending steps on pipes with a larger diameter, using a device according to  claim 1 , 
       said method comprising the steps of:
 clamping the tube in a first bending lock that is connected to a first bending arm, which can be rotated around a first rotational axis, 
 moving a second bending lock away from the pivoting area of the tube against the rotational direction and in perpendicular direction to the feeding direction of the tube to be bent, 
 bending a first section of the tube by advancing the tube, 
 while securing the tube, declamping the tube from the first bending lock, 
 moving the first bending lock from the pivoting area of the tube in perpendicular direction to the feeding direction of the tube to be bent, 
 moving the second bending lock into the pivoting area of the tube, 
 clamping the tube to be bent in the second bending lock, and 
 bending a second section of the tube by advancing the tube. 
 
     
     
         3 . A method as set forth in  claim 2 , wherein a rotation of the tube around the center axis of the tuba is carried out between two bending steps. 
     
     
         4 . A method as set forth in  claim 2 , wherein a longitudinal advance of the tube in the direction of the center axis of the tube is carried cut between two bending steps. 
     
     
         5 . A method as set forth in  claim 2 , wherein a multitude of bending steps is carried out in succession.