Method and device for forming a flange or a rim on an end of a steel pipe

Abstract

The invention relates to a method and device for forming a one-piece flange ( 10, 18 ) or rim on the end of a steel or sheet-metal ( 12 ) pipe. The pipe is placed in a flat position on all sides on the inner surface thereof close to the end thereof and is clamped. One part of the pipe ( 10 ) protrudes above the clamped section of the tube ( 12 ). The protruding part of the pipe is bent by applying surface pressure against a peripheral section on the inner surface thereof, until a desired outward flectional angle is obtained. The desired flectional angle on all parts of the pipe ( 10, 18 ) or a part or section ( 10 ) thereof is gradually achieved by rotating the pipe ( 12 ) relative to the peripheral section wherein the flexing occurs.

1 . Process for the unitary forming in of a flange or rim on an end of a pipe of sheet metal, thereby characterized, that the pipe ( 12 ) is subject to annular clamping tension along its internal surface near one of it's ends, wherein a segment of the pipe projects beyond the annularly clamped and tensioned internal surface, wherein at least one axial partial segment of the projecting pipe piece is bent outwards by the exercise of pressure against a segment of the circumference of it's inner surface, until achieving a desired angle of bend outwards away from the pipe axis, and that by the rotation of the pipe relative to said circumference of it's inner surface, in which the bending takes place, the desired angle of bend is imparted to the entire pipe piece or partial segment thereof.  
     
     
         2 . Process according to  claim 1 , thereby characterized, that a bending out of the pipe outer side at a location within the segment of the circumference in which the bending is taking place is prevented by exercising force from outside upon the pipe at the location of bending.  
     
     
         3 . Process according to  claim 2 , thereby characterized, that the exercise of pressure upon the location of bending occurs with reduced friction on the pipe rotating relative the location of bending.  
     
     
         4 . Process according to one of the preceding claims, thereby characterized, that for forming a multiple-bent flange, the process is repeated multiple times sequentially.  
     
     
         5 . Device for carrying out a process according to one of the preceding claims, characterized by a clamping disk ( 22 ) with cylindrical circumference surface ( 48 ) introducible into the inside of the pipe ( 12 ), which is adjustable between a resting setting spaced closely to the inner surface of the pipe ( 12 ) and a spread setting with frictional engagement against the inner circumference of the pipe, a drive shaft ( 24 ) mounted fixed against rotation relative to the clamping disk ( 22 ), a drive motor ( 146 ) for rotating the drive shaft ( 24 ) against great resistance, and a bending jaw ( 26 ,  30 ) pivotable between a rest position lying against the inner side of the pipe to be bent ( 10 ,  18 ) and a work position representing the finished bent pipe piece ( 10 ,  18 ) with an at least partially cylindrical contact surface ( 190 ) for contact with the pipe piece ( 10 ,  18 ), wherein the cylindrical diameter of the contact surface ( 190 ) is smaller than or equal to the diameter of the pipe piece to be bent ( 10 ,  18 ) and the cylinder height of the contact surface ( 190 ) is greater than the length of the pipe piece.  
     
     
         6 . Device according to  claim 5 , characterized by a shaping roller ( 32 ,  34 ) moveable between a rest position spaced from the pipe ( 12 ) and a working position lying against the outer surface of the pipe ( 12 ) at the bending edge ( 16 ,  20 ) of the pipe piece ( 10 ,  18 ) to be bent, which shaping roller ( 32 ,  34 ) is mounted rotatably on a mounting block ( 104 ), which with the mounting block ( 104 ) is held fixed against rotation relative to the pipe axis ( 28 ).  
     
     
         7 . Device according to  claim 5  or  6 , thereby characterized, that the clamping disk ( 22 ) is comprised of multiple sectors ( 118 ), which can be adjusted between a resting setting and a spread setting of the clamping disk ( 22 ) by a spreading device ( 120 ,  122 ,  124 ).  
     
     
         8 . Device according to  claim 7 , thereby characterized, that the spreading device is comprised of a widening end ( 120 ) of a pull rod ( 122 ), which with slanted side surfaces ( 136 ) widening relative to the pipe axis ( 28 ) cooperate with the inner ends of the sectors ( 118 ) of the clamping jaws ( 132 ), wherein the pull rod ( 122 ) is connected to a pull means ( 124 ).  
     
     
         9 . Device according to  claim 8 , characterized by a spring biased reset device for returning the sectors ( 118 ) from the work setting to the rest setting.  
     
     
         10 . Device according to  claim 5  or  6 , thereby characterized, that the clamp disk ( 22 ) is comprised of an externally cylindrical and inner conical slitted clamping ring ( 174 ) and a clamping plate ( 180 ) with conical outer surface lying against the inner conical inner surface ( 176 ) of the clamping ring ( 174 ), which is associated with a pull rod ( 122 ) with pull drive means ( 124 ).  
     
     
         11 . Device according to  claim 10 , thereby characterized, that the slit ( 172 ) of the clamping ring ( 174 ) is slanted relative to the longitudinal axis ( 28 ) of the clamping ring.  
     
     
         12 . Device according to one of  claims 5  to  11 , thereby characterized, that at one or more locations of the support surface ( 190 ) one or more support rollers ( 194 ) is introduced in a recess of the contact surface ( 190 ) of the bending jaw ( 26 ), which projects slightly beyond the contact surface ( 190 ) and is mounted rotatable about a shaft ( 196 ) parallel to the cylinder axis of the contact surface ( 190 ).  
     
     
         13 . Device according to  claim 12 , thereby characterized, that multiple parallel support rollers ( 194 ) are seated in recesses in the contact surface ( 190 ) of the bending jaw ( 26 ) spaced apart from each other.  
     
     
         14 . Device according to one of  claims 5  to  11 , thereby characterized, that the bending jaws ( 26 ) is a fully cylindrical bending roller, which is mounted rotatably about a rotation shaft ( 200 ) extending in the cylinder axis, wherein it's rotation mount is pivotable between work and rest positions together with the bending rollers.  
     
     
         15 . Device according to one of  claims 6  to  14 , thereby characterized, that the shaping rollers ( 32 ,  34 ) exhibit on their outer circumference a tip ( 36 ,  38 ) which in cross-section is rounded or sharp edged, which tip transitions to flanks ( 40 ,  42 ), which define the desired bending angle ( 14 ,  20 ) of the flange ( 10 ,  18 ) or the angle of the rim.  
     
     
         16 . Device according to one of claims  5  through  15 , thereby characterized, that the pivotable bending jaws ( 26 ) and the shaping rollers ( 32 ) with their associated mounting and drive elements and assembled into an integrated stable work unit, which is rotatable about the pipe axis ( 28 ) relative to a work unit comprised of pipe ( 12 ) and clamp disk ( 22 ) including mounting and drive elements.  
     
     
         17 . Device according to  claim 16 , thereby characterized, that multiple work units ( 26 ,  32 ) are distributed about the circumference of the pipe ( 12 ), which are respectively adapted for carrying out one of the bending processes for the formation of a flange ( 10 ,  18 ) with multiple bends.  
     
     
         18 . Device according to  claim 17 , thereby characterized, that the work units ( 26 ,  32 ) are respectively provided on moveable sleds ( 70 ) for adaptation to the various diameters of the pipe ( 12 ).  
     
     
         19 . Device according to one of  claims 1  to  18 , thereby characterized, that the work unit ( 26 ,  32 ) includes two side plats ( 80 ), which are rigidly connected with each other on opposite ends via intermediate plates ( 82 ), that between the side plates ( 80 ) a broad sector plate ( 84 ) extends, on the two sides of which facing the side plates ( 80 ) respectively multiple guide rollers ( 94 ) are rotatably mounted, which run along arc shaped guide grooves ( 96 ) on the inner side of each side plate ( 80 ), and that the sector plate ( 84 ) carries the bending jaws ( 26 ) of the work unit.  
     
     
         20 . Device according to  claim 19 , thereby characterized, that the sector plate ( 84 ), in cross section taken parallel to the sector plate ( 80 ), forms an incomplete arc, of which the middle section opposite the circular arc ( 88 ) is missing, wherein the straight lines ( 90 ,  92 ) connecting to the arc ( 88 ) intersect outside the center point of the arc ( 88 ), and that the surface of the sector plate ( 84 ) defined by line ( 92 ) is connected to the bending jaw ( 26 ).  
     
     
         21 . Device according to  claim 20 , thereby characterized, that gear teeth are provided on the cylindrical surface of the sector plate ( 84 ) corresponding to the arc ( 88 ), which are in engagement with a drive pinion ( 102 ) driven by a drive means ( 100 ).  
     
     
         22 . Device according to one of  claim 5  to  21 , thereby characterized, that two such devices ( 204 ) are provided mounted on a rail system moveable in the direction of the pipe axis ( 28 ) for processing the two ends of a pipe, and that a drive ( 208 ) is provided for moving the associated devices ( 204 ) towards and away from the oppositely lying ends of the pipe ( 12 ).