EP1320429B1 - Method and device for forming a flange or a rim on an end of a steel pipe - Google Patents

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.

Description

The invention relates to a method according to the preamble of claim 1 and a device according to the preamble of Claim 5 (see, e.g., GB-A-1 202 144).

It refers in particular to relatively thin-walled tubes, including a diameter range of about 100 to 3000 mm and Wall thicknesses of 0.5 to 6.0 mm are understood. Such pipes are mainly used for air ducts, fan housings, Device housing and the like in the ventilation, air conditioning and extraction technology, but also used in process engineering.

There are different types of connection to individual pipe sections tightly and firmly connect with each other. They have decisive influence on economic efficiency and technical Properties of a pipe system. So far, far mainly manufactured separately, placed on the pipe end and attached to this angle, flat or other Profile flanges used, although the benefits of direct, i.e. in one piece to the pipe ends integrally formed flanges evident are and therefore a need for such molded Flanges and Borden exists. The reason for this is in Lack of a procedure to see that the molding of sophisticated Flange forms at the ends especially large volume Pipes with acceptable cost allows. In Shapes Today only radially projecting ring rims with relatively low stability or radially projecting flat flanges, which are punched for screwing. Latter are mainly used for fan housings. The Simple shelves can be used with two rollers on beading and flanging machines getting produced. The later perforated flat flanges are produced by printing. It is the Tubular body brought into high rotational speed, which only for very short tubular bodies such as axial fan housings is possible. The pipe end is in a negative form of the to be formed flat flange. With a lever, on whose At the end of a roll, is now on the fast-moving Pipe end "pressed" until the material comes to flow and adapts to the negative mold. The "push" method is similar the deformation of clay on the potter's wheel. It will also be for the application of ring rims to short tube rings, The then then attached to a pipe end and it be attached. This latter method is for example in DE 196 32857 A1.

Suitable for molding flanges directly to a pipe end This known method is bad, since it is almost impossible and also dangerous, larger pipes in the necessary To bring circulating speed. Also, the effort is for many forms for the variety of different tubes for one economic work way too high. Above all, though producing more sophisticated flange shapes, such as e.g. Cone flanges or the like, because of the occurring Undercuts not possible because the shape of the finished Flange could not be removed anymore.

For making boxes, frames, profiles or channels with straight edges is the so-called Abkantverfahren or Schwenkbiegeverfahren known. This is a flat metal sheet between a fixed lower beam and a movable one Cheek clamped and with the help of a hinged bending cheek folded. The big advantage is that when pivoting a whole sheet metal section without any stretching can be raised or folded. Only in Area of the forming edge, the sheet material must flow. All other material remains completely unchanged. Therefore are edge profiles without stretching and without special Effort exactly straight and stress-free. In contrast to becomes in the above "pressing" the entire material durchgewalkt and thereby fraught with corresponding voltages. As a result, the energy required for the swivel bending much lower.

The present invention now seeks a method and a To provide apparatus for carrying out this method with which the one-piece molding also more complicated Flanges and shelves not only on short, but in particular also on long pieces of pipe with economic effort is possible.

This object is achieved according to the method by the features of claim 1 and in terms of Device solved by the features of claim 5.

The dependent claims are on advantageous embodiments of Directed invention.

The basis of the method according to the invention is the advantages the linear swivel bending process also during bending use of pipe ends. It is therefore called circular-swivel bending method designated.

Of course, the linear swivel bending process can not be transferred without modifications to round tubes, as in these not straight, but curved edges are generated must and even with different radii possible to be produced without tool change. The invention accomplishes this by round clamping of the pipe end from the inside forth, e.g. by means of a clamping washer. This clamping disc has before clamping a slightly smaller diameter as the pipe inside diameter. After insertion she will spread, i. the diameter is increased until they reach clamped with the outer circumference against the inside of the pipe wall. The clamping disc or other used for clamping Device can be equipped with a strong drive axle for the Execution of the tube rotation to be connected. The firm clamping of the pipe end is thus simultaneously for turning the Pipe exploited, of course, only much lower Speeds are required as the pressing method. It must in any case enough friction between the inside of the tube and the Clamping device, e.g. Clamping disc, arise, so that Tube are turned against the resistance of the bending tools can.

In principle it is also possible to use the pipe and the so non-rotatably connected parts of the device stand still leave and the bending tools and the rotatably connected Turn parts around the tube axis.

The subsequent bending up of a projecting pipe section to a board or flange then takes place during the rotation of the Pipe progressing around the circumference of the aufzubiegenden pipe section. For this purpose, preferably a pivotable bending jaws used in its home position or park position the inside of the tube end abuts. Its axial width should at least be slightly larger than the section to be bent of the pipe end. This ensures that the the section to be bent is raised as a whole and its straight shape not changed. Preferably, the contact surface should of the bending jaw at the pipe end have the same radius like the inside of the pipe, so that the section of the pipe to be bent Pipe end has a large-scale edition. Basically but also a cylindrical shape of the bearing surface of the bending jaw with a slightly smaller radius than the pipe inside possible. Since the pivotable bending jaws each only one Part of the tube circumference can bend, the tube must be in a uniform slow rotation. If that is Pipe turns, so the bending jaws slowly into the position pivoted the desired bending angle. This invention The method can therefore be properly used as a circular pivot bending method describe.

In an advantageous embodiment of the invention may additionally a pressure on the bending point of the pipe from the outside of the tube, conveniently by a forming roller or the like, be exercised, with a tip of the forming roll cross section ends at the point where the pipe end is bent shall be. This allows the shape of the bending edge (pointed or around) can be determined quite accurately. Otherwise, the Cross-sectional shape of the form roller by the maximum bending angle of the Anformprofils determined. As the form role in Bending process act considerable forces is the prerequisite Therefore, to achieve a clean bending edge strong support and storage of the form roller. advantageously, will the form roller and its holder with the likewise fixed and non-rotating bending jaws and its Drive devices connected to a fixed unit, whereby the stability of the device significantly increased becomes.

For lower demands on the dimensional accuracy of the molded Flange or Bordes it is at relatively low Pipe wall thickness possible, without using a form roller too to bend. In this case, it is the curvature of the pipe wall, which gives enough support for bending. Sharp bending edges are not possible, however, and with increasing Sheet thickness, the radius of the bending edge is getting bigger.

Figuren 1 bis 12 die Arbeitsabfolge des erfindungsgemäßen Verfahrens anhand von aufeinanderfolgenden Arbeitsschritten zum Anformen eines Konusflansches an das Ende eines Rohres, wobei die schematisch in Seitenansicht eingezeichneten Vorrichtungsteile nur als Beispiel für die dadurch zu erzielenden Bearbeitungswirkungen des Verfahrens dienen und auch durch andere oder anders geformte Einrichtungen ersetzt werden könnten,

Figur 13 eine schematische Seitenansicht einer ersten Ausführungsform der Vorrichtung zur Durchführung des erfindungsgemäßen Verfahrens in einer ersten Arbeitsstellung,

Figur 14 eine der Fig.13 entsprechende Seitenansicht der Vorrichtung in einer zweiten Arbeitsstellung,

Figur 15 eine der Fig.13 entsprechende Seitenansicht der Vorrichtung in einer dritten Arbeitsstellung,

Figur 16 einen schematischen Teilschnitt längs der Linie XVI-XVI in Fig.13,

Figur 17 eine schematische Stirnansicht der bei der Vorrichtung gemäß Figuren 13 bis 18 verwendeten Spannscheibe,

Figur 18 eine schematische Seitenansicht der in Fig. 17 gezeigten Teile,

Figur 19 eine schematische Seitenansicht eines Spannscheibe, Rohr und deren Antriebseinrichtung umfassenden Teils der erfindungsgemäßen Vorrichtung,

Figur 20 eine gegenüber der Fig.19 wiederum verkleinerte geschnittene Seitenansicht eines Teils der in Fig.19 dargestellten Bestandteile,

Figuren 21 und 22 Axialschnitt bzw. schematische Seitenansicht einer anderen Ausführungsform der Spannscheibe,

Figuren 23 und 24 schematische Seitenansichten von Rohr, Spannscheibe, Biegebacken und Formrolle bei unterschiedlicher Stellung des Biegebackens,

Figuren 25 bis 29 eine schematische Teilseitenansicht einer Spannscheibe und eines Biegebackens in verschiedenen Biegestellungen mit unterschiedliche Querschnitte aufweisenden Formrollen bzw. ohne Formrolle,

Figuren 30 und 31 teilweise weggebrochene schematische Schrägansichten von Teilen einer erfindungsgemäßen Vorrichtung mit Rohr, Spannscheibe, Formrolle und Biegebacken in Parkstellung bzw. Biegestellung des Biegebackens,

Figur 32 eine der Fig.30 entsprechende Teilschrägansicht ohne Rohr und Formrolle,

Figuren 33 bis 35 der Fig.32 entsprechende Teildarstellungen mit jeweils drei unterschiedlichen Ausführungsformen des Biegebackens, und

Figur 36 eine schematische Seitenansicht einer Ausführungsform mit zwei an beiden Enden eines Rohres gleichzeitig arbeitenden erfindungsgemäßen Vorrichtungen.

The course of the method according to the invention and preferred embodiments of the device according to the invention will be explained in more detail with reference to the figures. Show it:

Figures 1 to 12, the sequence of operations of the method according to the invention by means of successive steps for molding a cone flange to the end of a tube, wherein the schematically drawn in side view device parts serve only as an example of the thereby to be achieved processing effects of the method and by other or differently shaped devices could be replaced,

13 shows a schematic side view of a first embodiment of the device for carrying out the method according to the invention in a first working position, FIG.

FIG. 14 shows a side view of the device corresponding to FIG. 13 in a second working position,

FIG. 15 shows a side view of the device corresponding to FIG. 13 in a third working position,

FIG. 16 shows a schematic partial section along the line XVI-XVI in FIG.

FIG. 17 shows a schematic end view of the clamping disk used in the device according to FIGS. 13 to 18,

FIG. 18 shows a schematic side view of the parts shown in FIG. 17,

FIG. 19 is a schematic side view of a tensioning pulley, tube and part of the device according to the invention comprising the drive mechanism thereof;

FIG. 20 is a sectional side view, once again reduced in size relative to FIG. 19, of a portion of the components illustrated in FIG.

FIGS. 21 and 22 show an axial section or schematic side view of another embodiment of the tensioning disk,

FIGS. 23 and 24 show schematic side views of pipe, clamping disk, bending jaws and forming roller with different positions of the bending jaw,

FIGS. 25 to 29 show a schematic partial side view of a clamping disk and a bending bit in various bending positions with different cross-sections of forming rollers or without a form roller,

FIGS. 30 and 31 are diagrammatic oblique views, partly broken away, of parts of a device according to the invention with tube, tensioning pulley, forming roller and bending jaws in parking position or bending position of the bending jaw,

FIG. 32 is a partial oblique view corresponding to FIG. 30 without tube and forming roller;

Figures 33 to 35 of Figure 32 corresponding partial views, each with three different embodiments of the bending jaw, and

Figure 36 is a schematic side view of an embodiment with two at both ends of a tube simultaneously working inventive devices.

Figures 1 to 12 each illustrate in schematic Partial representations the operation of the invention Procedure at a pipe end. Fig.1 shows a to Simplification largely broken part section through an unprocessed, in Fig.1 right-pointing pipe end 10 of a tube 12 with a circular cross-section. Fig.2 shows the state of the pipe end 10 after the first processing step. The pipe end 10 is to be bent pipe section become, along a rounded bending edge 14, for example by about 150 ° against the axial direction 16 of the tube 12 is bent outwards. 3 shows the condition of the pipe 12 after a second circular pivoting bending operation, in which the adjacent to the first piece of pipe 10 second pipe section For example, at a right angle to the Axial direction 16 with a sharp edge 20 to the outside is bent. Thus, one is from the contiguous Pipe pieces 10 and 18 existing cone flange emerged which is integrally formed on the tube 12.

The subsequent figures 4 to 12 illustrate schematically the operation of a device for carrying out the inventive method. In all figures are for the same or similar parts the same reference numerals used.

Figure 4 shows the tube 12 in not yet clamped state near a parked state not spread Clamping disc 22, at a clamping disc 22 under Force application in rotation offset drive shaft 24 fixed is appropriate. A first bending jaw 26 for bending the first pipe section 10 by 150 ° in one of Fig.2 corresponding Position is in Fig.4 in parking position before the bending process partially shown broken away. It should be noted that Figures 1 to 3 with respect to the figures 4 to 12 by 180 ° mirrored on the tube axis 28 perpendicular plane are. A second bending jaw 30 is with respect to first bending bit 26 is rotated by 180 ° about the tube axis 28 also in its rest position before the bending process partially shown broken away. The second bending jaw 30 serves to bend the second pipe section 18 by 90 ° the axial direction 16 in the Fig.3 corresponding Position. 4, a first forming roller 32 and a second forming roller 34 each in their parking positions shown removed from the tube 12. The first form role has a rounded tip section 36 whose flanks 40 enclose an angle of 30 °. 180 ° around the pipe axis 28 is rotated a second forming roller 34 in its parked position provided away from the tube 12, whose cross section has a sharp edge 38 and its flanks 42 a include right angle. The illustrated position of the device parts corresponds to the starting state of the process.

Fig.5 shows a following working condition in which the Clamping disc 22 retracted into the tube 12 and according to the Arrows 44 in his the tube 12 spanning from the inside Spreading is extended. Together with the Clamping disk 22 are the bending jaws 26 and 30 in the pipe end have been retracted, however, in terms of their pivoting to bending the pipe end both still in the parking position. Likewise, there are the two form roles 32 and 34 still in the parking position as in the state of Fig.4. At the same time, the drive shaft 24 according to the arrow 46 in Rotation offset, so that the clamping plate 22 together with the tube 12 rotates while the bending jaws 26 and 30 and the forming rollers 32 and 34 are not about the tube axis 28th rotate. The frictional resistance between the cylindrical Outer surface 48 of the clamping disk and the inner surface of the Pipe 12 is by tensioning the tensioning pulley 22 in their Working position according to Figure 5 so large that the tube 12th also turns against great resistance.

The next step of the machining process is in 6, in which the first forming roller 32 according to the Arrow 50 along the shift axis 52 in their at the Outside of the tube 12 tight-fitting working position procedure is.

According to FIG. 7, the first bending jaw 26 is then moved according to FIG the arrow 54 from its parking position (Figure 6) in its working position (Fig.7) by an angle of 150 ° to one on the plane perpendicular axis pivots, thereby the first over the tension pulley 22 protruding pipe section 10 around the first forming roller 32 bent by 150 ° outwards becomes. Since at the same time drive shaft 24 and clamping disk 22 together with the clamped tube 12 to the tube axis 28th turn, after a few turns of these parts to the Pipe axis 28, the pipe section 10 without distortion around the rounded Edge 14 of tube 12 bent by 150 ° outwards. By the rotatable mounting of the forming roller 32 is at the bending point occurring frictional resistance with the pipe section 10th significantly reduced.

Subsequently, as shown in Fig.8, the first forming roller 32 along the displacement axis 52 according to the arrow 56 from the working position back to their parking position away from the tube 12 retracted and at the same time the first bending jaws 26 off his job according to arrow 58 back to his Parking position swung back.

The next step according to Figure 9, the second Form roller along the displacement axis 60 according to the arrow 62 from the parking position to the working position in fixed Move system on the outside of the tube 12. These processes all take place while the drive shaft 24, the Turn the clamping disk 22 and the tube 12 about the tube axis 28 and first bending jaws 26, second bending jaws 30 and the both form rollers 32 and 34 are fixed. Conveniently, Therefore, the rotating parts and not themselves rotating parts each to a stable work unit summarized. Within the non-rotating work unit must, of course, the mobility of the individual parts each ensured from the parking position in the working position be. On the other hand, it is of course possible, the from drive shaft 24, clamping disk 22 and tube 12 existing To let the work unit rest and the other, from the Bending jaws and the forming rollers existing work unit to turn the tube axis 28.

In the subsequent step according to FIG. 10, the second Bending jaws 30 according to the arrow 64 from its parking position in the working position pivots, whereby the second on the Clamping disc 22 protruding pipe section 18 by 90 ° with a corresponding to the cross section of the second forming roller 34 sharp bending edge 20 is bent by 90 ° to the outside. The complete bending of the second pipe section 18 from the pipe 12th away to the outside is achieved when the rotating parts 24,22 and 12 a few turns around the tube axis 28 executed to have.

In the next step according to Figure 11, the second Form roller 34 along the displacement axis 60 according to the arrow 66 back to their parking position away from the tube 12 retracted and the second bending jaw 30 is according to the arrow 68 swung back into its parking position.

Thus, the way is clear for the return of all parts in the in Figure 4 shown starting position. At the end of the editing Therefore, all parts are again in accordance with Figure 12 the starting position according to Figure 4, and as a result of the invention Operation is at the end of the tube 12th a flange with the pipe sections 10 and 18 integrally formed.

In Figures 13 to 16 is a preferred embodiment the device for carrying out the method according to the invention with its parts essential to the invention schematically shown. For better clarity are of individual Parts are broken away, for example from tube 12, the tension pulley 22, the drive shaft 24 and the bending jaw 26. It is further noted that in the illustrated Device only a bending jaws 26 and a forming roller 32nd are shown for a single bending operation of a projecting pipe section 10 are suitable. Of course can be distributed around the pipe axis 28 outside the drawing plane further bending jaws and forming rollers are provided. Your Explanation in detail, however, can be omitted since they work in the same way as the ones in the figures 13 to 16 parts shown. If for each bending edge a separate work unit made of bending jaws and forming roll is used, then it has the advantage that for the individual Work steps no tools are changed have to. Especially in mass production, it is important that the Work units one after the other without mutual Intervention can be used.

Each comprising a bending jaws 26 and a forming roller 32 Work unit is always on a movable carriage 70 mounted, with several carriages radiating on one Base plate 72 may be arranged. That way you can the individual work units slightly to the respective diameter adapted to be processed pipe 12. Everyone Carriage 70 may be along two parallel carriage guides 71 according to the double arrow 74 along one of a rotary drive 76 offset in rotation threaded spindle 78 are moved.

On the carriage 70 are spaced apart two parallel Side panels 80 (Fig.16) attached by intermediate plates 82 are rigidly interconnected frame-like. Between the two side plates 80 slidably extend to the Inner sides of the side plates 80 adjacent a wide, approximately sector-shaped sector plate 84, on which means Screws 86 of the bending jaws 26 is attached. The sector plate 84 forms in its from Fig.13 to be seen cross-section parallel to the side plates 80 an incomplete Circular sector whose arc 88 opposite Middle section is missing, since the center of the circular sector the Bending process of the pipe section 10 must be reserved. The at the circular arc 88 subsequent lines 90 and 92 meet outside the center of the arc 88. The Bending jaws 26 is at the one line 92 corresponding Surface of the sector plate 84 fixed by the screws 86.

It should be noted that in Fig.16 in contrast to the figures 13 to 15 only required for pivoting the bending jaw 26 Parts of the device are shown.

The leadership of the sector plate 84 in the required pivoting along with the bending jaws 26 takes place by Guide rollers 94, which in arcuate guide grooves 96 run in the side plates 80. The guide rollers 94 stand on both sides of the sector plate 84 and are each guided in a guide groove 96. In the circular arc 88 the cross section of the sector plate 84 corresponding cylindrical Peripheral surface of the sector plate 84 is a serration 98 provided, which is driven by a rotary drive 100 Drive pinions 102 is engaged. The sector plate 84 can thus from the parking position of the bending bale 26 according to Figures 13 and 14 corresponding position in one of the working position the bending jaw 26 corresponding position 15 are pivoted. The tilt angle of the sector plate 84 can be largely freely chosen and corresponds in the present case the angle between the two flanks of the cross section of the forming roller 32nd

From FIGS. 13 to 15 it can also be seen that the Form roller 32 about its central axis 105 rotatably in a fork-shaped Bearing 104 is mounted, which in turn according to the double arrow 50.56 from its parking position according to Fig.13 in a working position according to Fig.14 is movable. To the procedure of the bearing block 104 is one of a drive motor 108 driven threaded spindle 106 is provided. It's important, that the bearing block with form roller in the working position according to Figures 14 and 15 fixed and heavy duty with the working unit made of bending jaws, forming roll and associated parts is.

In the working state of Figures 13 to 15 is the clamping disc 22 retracted by sliding the tube 12 into the tube end, while relaxing in the above described Parking position is located. Subsequently, the clamping disc 22 in the manner described below in its working position expanded and now spans the tube 12 of Cylindrical inside. This results in an over the cylindrical outer surface of the clamping plate 22 protruding Pipe piece 10, which is bent by the subsequent bending process shall be. Before pushing the tube 12 on the Clamping disk 22 is made of bending jaws, forming roll and associated storage and drive facilities existing Working unit by moving the carriage 70 along the Double arrow 74 with respect to the fixed base plate 72 so adjusted to the diameter of the pipe 12 is adapted. In FIGS. 13 to 15, only one is shown Work unit shown. Further work units can be used on the base plate 72 with radiating from the Pipe axis 28 leading away, usually double slide guides 71 are mounted so that they are used successively on Tube 12 can come to each a piece of pipe to a part to deform a complicated flange. To every sled 70 is a rotary drive 76 with threaded spindle 78, a threaded rotor 110 running on the threaded spindle 78 and a holder 112 connecting the carriage 70 therewith provided, wherein the holder 112 in a radial to the tube axis 28 extending slot 114 of the base plate 72 is moved can be.

The following is the training and mode of action of a first embodiment of the clamping plate 22 with reference to the figures 17 to 20 explained in more detail. Because the task of the clamping disk 22 consists of all changes in shape of the pipe inside to prevent is as full as possible Plant their cylindrical peripheral surface 116 on the pipe wall important. The illustrated preferred embodiment of Clamping disc therefore has a division into several, in illustrated embodiment six sectors 118, the in a manner to be explained in more detail below by the expanding end 120 one with an axial drive, for example in the form of a hydraulic cylinder 124 provided drawbar 122 from that in the left half of Figures 17 and 18th illustrated inner parking position in one in the right Half of Figures 17 and 18 shown outer working position in a tensioned system on the inside of the tube 12 be spread. The number of sectors is arbitrarily large. Here, a larger number of sectors has the advantage that the Column 126 between the sectors 118, which during spreading the clamping disc 22 arise, become smaller and of the Wall of the tube 12, even if it is very thin-walled, without Shape change of the pipe to be bridged. The sectors 118 are circular ring sectors and ends in the distance from the Pipe axis 28 in a cylinder cut-shaped inner surface 128. The radial width of the sectors 118 can be chosen freely be to the diameter of the clamping plate 22 the respective Adjust the diameter of the tube 12. This adjustment can by simply replacing the sectors 118. The Inner surfaces 128 of the sectors 118 are located on the cylindrical Outer surfaces 130 of circular sector-shaped clamping jaws 132nd at. The sectors 118 are connected by radial screws 142 to the Clamping jaws 132 attached. The jaws 132 have a with respect to the tube axis 28 oblique inner face 134, each on a side surface 136 of the widening End 120 of the pull rod 122 abut. In the illustrated Embodiment, the expanding end 120 has a Hexagonal cross-section, so that each have a side surface for each of the six jaws 132 is provided.

The intended for rotating the clamping disk and the tube 12 Main drive shaft 24 is centrally pierced axially, and this Bore is penetrated by the tie rod 122. By operation the hydraulic cylinder 124 can be the drawbar 122nd from the parking position shown in the lower half of Fig.19 138 in the in the upper half of Fig.19 shown Move spreading or working position 140. Thereby For example, the sectors 118 are selected from those in the left halves of FIG Figures 17 and 18 illustrated parking position in low Distance from the inner surface of the tube 12 in the right Halves of Figures 17 and 18 shown on the inner surface of the tube 12 under pressure applied working position adjusted. This adjustment is made by an appropriate Displacement of the clamping jaws 132 mediated.

The drive shaft 24 passes through a cutout 144 of the Base plate 72 of the entire device and is in a the Professional common sense rotatably mounted and by a Drive motor 146 with hollow shaft gear 148 in rotation added. The opposite end of the drive shaft 24th has a mushroom-shaped extension 150 with a plan End face 152, on the plane sliding surfaces 154 of the clamping jaws 132 radially slidably abut. The sliding surfaces 154th opposite sliding surfaces 156 of the clamping jaws are applied the plane inner surface of a counter-disc 158 slidably, by screws 160 on the mushroom-shaped extension 150th is attached. The screws 160 enforce advanced Holes 169 in the jaws 132, which the required allow slight radial displacement of the jaws 132.

The screws 160 are comprised of spacers 162 which together with the holes 169 of the jaws 132 a linear ensure radial guidance of the clamping jaws 132.

The hydraulic cylinder 124 for actuating the drawbar 122 is axially supported on the hollow shaft gear 148. The in itself already large force of the hydraulic cylinder 124 can be through the taper of the expanding end 120 of the drawbar 122 with respect to the pipe axis 28 again increase arbitrarily. Thus, the necessary large clamping force is generated, which one sufficient frictional engagement of the clamping plate 22 to the pipe wall generated to the pipe against the resistance of the bending tools (Bending jaws 26 and forming roller 32) to rotate. Of course can be the bevel of the expanding end 120 are also reversed, i. in Fig.19 to the right, when working with a differently actuated push rod becomes.

The retrieval of the jaws 132 while relaxing the Clamping disc 22 back to its parking position can be on easy Way done by springs, not shown, which in the individual jaws are inserted, or by a running around the outer periphery of the jaws, also not shown endless tension spring, which in a not shown groove is inserted.

Alternatively, the drive shaft 24 at one in Fig.20 illustrated embodiment also with a ball slewing ring 164 are stored, the outside (or inside) is provided with a toothing 166. The drive motor 146 is set next to the bell ring 164 in this case. The Pinion 168 of its output shaft 170 engages in the toothing of the ball turntable 164 and provides for the drive of the Drive shaft 24. Of course, there are others, the Professional common types of storage possible.

Another advantageous embodiment of the generally 22nd designated clamping disc and its drive is in the Figures 21 and 22 shown. In this embodiment the tensioning pulley 22 is running around the circumference, by a sloping slot 172 split clamping ring 174th with cylindrical peripheral surface 116 and conical inner surface 176 on. At the conical inner surface 176 is the same Conicity owning outer surface 178 of a clamping plate 180th which widened by means of bolts 182 and nuts 184 on End 186 of the tie rod 122 is attached. By moving the drawbar 122 in the sense of the double arrow 188 between the in the upper halves of Figures 21 and 22 shown relaxed parking position and in the lower halves Figures 21 and 22 shown tensioned working position can the clamping ring 174 with arbitrarily large force relax or relax. In itself would be a in axial direction parallel to the tube axis 28 extending Slot of the clamping ring 174 possible. The oblique arrangement of the Slot 172 prevents, however, that during clamping itself opening gap a gap in the clamping of the pipe wall caused and therefore deformed at this point. The retrieval of the clamping ring 174 when relaxing takes place in this case by the spring action of the clamping ring itself. If necessary, this spring effect is not a represented, circulating endless tension spring in a groove of the Reinforcing clamping ring 174.

It is readily apparent that the sheet thickness of Pipe 12, the desired flange shape or a material change do not affect the clamping plate 22. The pipe end 10,18 is pushed so far over the tension pulley 22, until enough material for the molding of a desired flange is available.

In the following figures 23 to 35 are advantageous Embodiments of bending jaws 26 and shaping rollers 32 together with a portion of the tube 12 to be deformed as well a portion of the spread clamping disk 22 is shown. The Figures 23 and 24 show a first embodiment of this Parts, wherein in the manner described above in the Working position moved forming roller 32 on the outside of the Pipe 12 presses. The in the manner described above pivotable bending jaws 26 is in its parking position the inside of the over the clamping disc 22 protruding, too bending pipe piece 10, wherein the pipe wall between Clamping disk 22 and forming roller 32 clamped and held is. The tip 36 of the cross section of the forming roller 32 terminates the point where the projecting pipe section 10 are bent should. Due to the shape of the forming roller 32, the shape of the Bending edge can be determined at the pipe end.

The pivotable bending jaws 26 is in its parking position according to Fig.23 on the inside of the pipe section 10 at. His axial width should be at least slightly larger than that axial length of the pipe section to be bent 10. This is Ensure that the piece of pipe to be bent as a whole is raised and its straight shape does not change. As well should the cylindrical contact surface 190 of the bending barb 26th have the same radius at the end of the pipe as the pipe inside, so that the pipe section 10 to be bent a large-scale edition Has.

Since the pivotable bending jaws 26 each only a portion of the tube circumference can bend, the tube 12 in a uniform slow rotation. Is that turning? Tube 12, so the bending jaws 26 is slow to the position pivoted the desired bending angle (Fig.24). In this working position remains the bending jaws 26 to the End of a final complete revolution of the tube 12 to the tube axis 28, whereby the bending of the pipe section 10th finished.

So that the tube 12 after the molding of the flange or Bordes can be deducted from the clamping plate 22, the form roller 32 with her bracket 104 in one of the tube sufficient far away parked be driven. For another Circular bending process now enters another unit of work, which is set to a different bending angle, in action in the manner described above.

For more convenient insertion of the clamping plate 22 in the pipe end 10, the insertion side of its cylindrical outer surface 48th have a conical taper 192.

FIGS. 25 to 28 show various embodiments the forming roller 32 or 34 with a slender tip 36 and rechtwinkliger Tip 38 shown. The tip 36 serves for Bending the pipe section 10 by 150 ° while the tips 38 serve to bend the pipe section 10 by 90 °.

In Fig.29 is shown schematically how to lower at Claims to the dimensional accuracy of the molded flange or Bordes without form roller only with clamping disc 22 and Bending jaws 26 can bend.

Figures 30 and 31 show an embodiment of the Biegebackens 26 with almost semi-cylindrical bearing surface 190 in parking position (Fig.30) and working position (Fig.31).

Fig.32 shows a partial enlarged view on a slightly enlarged scale a slightly different shaped bending jaw 26 with flatter cylindrical contact surface 190 which by screws 86 at a partially shown, pivoting sector plate 84 is attached. The support surface 190 is located with full frictional force on the inner wall of the pipe, not shown at. In the following figures are some advantageous embodiments a similar bending jaw 26 as in Fig. 32, but with less friction between contact surface 190 and Pipe inner wall shown. In itself it is ideal if the Working radius of the contact surface 190 of the bending jaw 26 the Pipe inside diameter corresponds. Without serious disadvantages However, the radius of the contact surface 190 may also be smaller as the pipe inside radius. This makes it possible with the the same bending jaws several tube diameter in alternation too to edit. At the main bussing center in the middle of Contact surface 190 can substantially reduce Friction and abrasion in the body of the bending jaw 26 a roller bearing support roller 194 are used, the axis of rotation 196 parallel to the contact surface 190 runs and their Peripheral surface 198 slightly above the contact surface 190th protrudes. The pipe section 10 to be bent lies in this area then friction on the peripheral surface 198 of the support roller 194 on.

Further improve the bending jaws 26 by inserting a whole chain of support rollers 194 in the contact surface 190 in the same manner as the one support roller 194th according to Fig.34. In the illustrated embodiment of Fig.34 five such support rollers 194 are provided in a chain. The remaining parts of the contact surface 190 between the support rollers 194 prevent sagging of the wall of the tube 12th between the support rollers 194, causing waviness and stretching would lead.

A minimal friction between bending jaws 26 and the inner wall of the tube 12 is achieved when the bending jaw 26 according to Fig.35 as a solid cylinder with cylindrical contact surface 190th is formed, wherein the entire cylindrical bending jaws 26 about a rotary shaft 200 rotatably on the sector plate 84th is stored. Although the lowest friction is achieved because but usually not enough space for a large diameter of the cylindrically shaped bending jaw 26 available stands, you have disadvantages in the wave formation and stretching the pipe wall in purchasing. These disadvantages are smaller with larger pipe wall thicknesses, so that quite for sheet thicknesses from 1.5 mm with such a "bending roll" on Position of a bending jaw 26 can be worked.

The entire device according to the invention for carrying out the The circular pivot bending method according to the invention can optionally with both horizontal and vertical tube axis 28 are used, the former for straight tubes and to favor the latter for short tubular fittings is.

For a rational production of straight pipes with flanges 10,18 at both ends become two according to the invention Circular pivot benders 204 of the type described to a common, generally designated 202 rail system along this system according to the double arrow 206 movable put on so that the mutual, schematically indicated clamping disks 22 and bending jaws 26th face. Each device 204 may have its own driven threaded spindle 208 on the rail system 202 be moved.

To insert the tube 12, the devices 204 are moved apart, until the tube length of the tube 12 between the Clamping washers 22 fits. Thereafter both devices 204 travel together, the clamping discs 22 dive into the pipe ends until to a stop, which on the processing length of Pipe end is set. Both clamping disks 22 are in the working position is tense, and then it starts up Both sides simultaneously from the editing process. For removal of the tube 12, the devices 204 have to be moved apart again become.

LIST OF REFERENCE NUMBERS

10

first supernatant pipe section

12

pipe

14

bending edge

16

Axial direction of the tube

18

second supernatant pipe section

20

sharp bending edge

22

tensioning pulley

24

drive shaft

26

first bending jaws

28

pipe axis

30

second bending jaws

32

first form roll

34

second form roller

36

Tip first form roll

38

Tip second form roller

40

Flanks, first form roll

42

Flanks, second form roll

44

Arrows spread position

46

Arrow drive shaft

48

outer surface

50

arrow

52

displacement axis

54

arrow

56

arrow

58

arrow

60

displacement axis

62

arrow

64

arrow

66

arrow

68

arrow

70

carriage

71

slide guides

72

baseplate

74

double arrow

76

rotary drive

78

screw

80

side plates

82

intermediate plates

84

sector plate

86

screw

88

arc

90

Just

92

Just

94

guide rollers

96

guide

98

Perforation

100

rotary drive

102

pinion

104

bearing block

105

central axis

106

screw

108

drive motor

110

thread runner

112

holder

114

slot

116

peripheral surface

118

sectors

120

expanding The End

122

pull bar

124

Hydraulikzylinde

126

column

128

palm

130

exterior surfaces

132

jaws

134

face

136

side surface

138

parking position

140

working position

142

screw

144

neckline

146

drive motor

148

Hollow shaft gear

150

extension

152

face

154

sliding surface

156

sliding surface

158

counter-disk

160

screw

162

spacers

164

Slewing ring

166

Perforation

168

pinion

169

holes

170

output shaft

172

slot

174

clamping ring

176

palm

178

outer surface

180

chipboard

182

bolt

184

nuts

186

broadened The End

188

double arrow

190

contact surface

192

bevel

194

supporting role

196

axis of rotation

198

peripheral surface

200

rotary shaft

202

rail system

204

Circular Folding device

206

double arrow

208

screw

Claims (22)

1. A method for forming a flange or a rim on the end of a sheet metal pipe in one piece, whereby the pipe (12) is supported in planar fashion on all sides and clamped close to its end on its inner side, whereby a pipe section protrudes over the portion of the pipe that is supported in planar fashion and clamped,
   characterised in that first of all at least one axial sub-portion of the protruding pipe section is bent outwardly away from the pipe axis by the planar exertion of pressure against a peripheral portion of its inner surface up to the desired bending angle,
   and in that subsequently, by relative rotation of the pipe with respect to the circumferential portion in which the bending takes place, the desired bending angle is imparted to the entire pipe section or sub-portion.
2. A method according to Clam 1,
   characterised in that an outward bending of the outer side of the pipe at a point inside the circumferential portion in which the bending occurs is prevented by the exertion of pressure on the bending point from the outer side of the pipe.
3. A method according to Claim 2,
   characterised in that the exertion of pressure on the bending point takes place with low friction at the pipe that rotates relative thereto.
4. A method according to one of the preceding Claims,
   characterised in that the method is performed several times in succession to form a repeatedly bent flange.
5. An apparatus for performing the method according to one of the preceding Claims, having a strain washer (22), which can be inserted into the interior of the pipe (12) and has a cylindrical circumferential surface (48), and which can be moved between a parking position a slight distance from the inner face of the pipe (12) and an expanded position in frictional abutment at the inner face, having a drive shaft (24) connected in a rotationally fixed manner with the strain washer (22), having a drive motor (146) for rotating the drive shaft (24) against great resistance,
   and characterised by a bending jaw (26, 30) that can pivot between a parking position adjacent to the inner side of the pipe section (10, 18) to be bent and an operating position corresponding to the already bent pipe section (10, 18), and has an at least partially cylindrical bearing surface (190) to abut the pipe section (10, 18), wherein the cylinder diameter of the bearing surface (190) is less than or equal to the diameter of the pipe section to be bent (10, 18) and the cylinder height of the bearing surface (190) is greater than the length of the pipe section.
6. An apparatus according to Claim 5,
   characterised by a forming roller (32, 34), which can be adjusted between a parking position spaced from the pipe (12) and an operating position adjacent to the outer side of the pipe (12) at the bending edge (16, 20) of the pipe section (10, 18) to be bent and which is pivoted in a bearing block (104) which is held with the bending jaw (26, 30) in rotationally fixed manner with respect to the pipe axis (28).
7. An apparatus according to Claim 5 or 6,
   characterised in that the strain washer (22) consists of several sectors (118), which can be adjusted by an expansion device (120, 122, 124) between the parking position and the expansion position of the strain washer (22).
8. An apparatus according to Claim 7,
   characterised in that the expansion mechanism consists of a widening end (120) seated on a connecting rod (122), which interacts with inclined side faces (136) widening with respect to the pipe axis (28) at the inner end of clamping jaws (132) interacting with the sectors (118), the strain washer (122) being connected to a traction drive (124).
9. An apparatus according to Claim 8,
   characterised by a resilient restoring mechanism for the sectors (118) from the operating position into the parking position.
10. An apparatus according to Claim 5 or 6,
    characterised in that the strain washer (22) consists of an externally cylindrical and internally conical, slit straining ring (174) and a clamping plate (180) abutting the conical inner face (176) of the straining ring (174) and having a conical outer face which is seated at a connecting rod (122) with traction drive (124).
11. An apparatus according to Claim 10,
    characterised in that the slit (172) of the straining ring (174) runs obliquely to the longitudinal axis (28) of the straining ring.
12. An apparatus according to one of Claims 5 to 11,
    characterised in that a support roller (194), which protrudes slightly from the bearing face (190) and is pivoted around a shaft (196) parallel to the cylinder axis of the bearing face (190), is inserted into a recess of the bearing face (190) of the bending jaw (26) at one or more positions of its bearing face (190).
13. An apparatus according to Claim 12,
    characterised in that several parallel support rollers (194) are inserted spaced next to each other in recesses of the bearing surface (190) of the bending jaw (26).
14. An apparatus according to one of Claims 5 to 11,
    characterised in that the bending jaw (26) is constructed as a completely cylindrical bending roller, which is pivoted around its rotary shaft (200) running in the cylinder axis, its pivot bearing together with the bending roller being pivotable between the parking position and the operating position.
15. An apparatus according to one of Claims 6 to 14,
    characterised in that the forming roller (32, 34) at its periphery comprises a point (36, 38), which has a rounded or sharp-edged cross section and passes into adjacent plane flanks (40, 42), which together enclose an angle determined by the desired bending angle (14, 20) of the flange (10, 18) or rim.
16. An apparatus according to one of Claims 6 to 15,
    characterised in that the pivotable bending jaws (26) and the forming roller (32) are combined with their associated bearing and drive mechanisms to form a stable operating unit, which can rotate around the pipe axis (28) relative to a structural unit formed from the pipe (12) and the strain washer (22) together with the bearing and drive mechanisms.
17. An apparatus according to Claim 16,
    characterised in that several operating units (26, 32) are distributed around the periphery of the pipe (12), which in each case are suitable for performing a special bending operation during the formation of a repeatedly bent flange (10, 18).
18. An apparatus according to Claim 17,
    characterised in that the operating units (26, 32) are in each case mounted on moveable slides (70) for adaptation to the respective diameters of the pipe (12).
19. An apparatus according to one of Claims 16 to 18,
    characterised in that each operating unit (26, 32) comprises two side plates (80), which are connected rigidly to one another by two intermediate plates (82) at opposite ends,
    in that between the side plates (80) extends a wide sector plate (84), at whose two side faces pointing to the side plates (80) several guide rollers (94) are pivoted in each case, which run in arc-shaped guide grooves (96) at the inner side of each side plate (80),
    and in that the sector plate (84) bears the bending jaw (26) of the operating unit.
20. An apparatus according to Claim 19,
    characterised in that the sector plate (84) in the cross section taken parallel to the side plates (80) forms an incomplete sector, whose centre portion opposite the circular arc (88) is missing, the straight lines (90, 92) connected to the circular arc (88) meeting outside the centre point of the circular arc (88),
    and in that the bending jaw (26) is fixed to the face of the sector plate (84) corresponding to straight line (92).
21. An apparatus according to Claim 20,
    characterised in that provided in the cylindrical face of the sector plate (84) corresponding to the circular arc (88) is toothing (98), which engages with a driving pinion (102) that is actuated by a rotary drive (100).
22. An apparatus according to one of Claims 5 to 21,
    characterised in that two such apparatuses (204) are moveably mounted on a rail system running in the direction of the pipe axis to machine the two ends of a pipe (12),
    and in that one drive (208) is provided to move the associated apparatus (204) toward the opposite end of the pipe (12) and away from it.

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