EP2177288A2 - Procédé de cintrage mécanique de barres, notamment de tuyaux - Google Patents

Procédé de cintrage mécanique de barres, notamment de tuyaux Download PDF

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Publication number
EP2177288A2
EP2177288A2 EP20090013213 EP09013213A EP2177288A2 EP 2177288 A2 EP2177288 A2 EP 2177288A2 EP 20090013213 EP20090013213 EP 20090013213 EP 09013213 A EP09013213 A EP 09013213A EP 2177288 A2 EP2177288 A2 EP 2177288A2
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EP
European Patent Office
Prior art keywords
bending
rod
bent
length
desired shape
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP20090013213
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German (de)
English (en)
Inventor
Heinrich Rapp
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
RASI Maschinenbau GmbH
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RASI Maschinenbau GmbH
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Filing date
Publication date
Application filed by RASI Maschinenbau GmbH filed Critical RASI Maschinenbau GmbH
Publication of EP2177288A2 publication Critical patent/EP2177288A2/fr
Withdrawn legal-status Critical Current

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D7/00—Bending rods, profiles, or tubes
    • B21D7/02—Bending rods, profiles, or tubes over a stationary forming member; by use of a swinging forming member or abutment
    • B21D7/024—Bending rods, profiles, or tubes over a stationary forming member; by use of a swinging forming member or abutment by a swinging forming member
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D7/00—Bending rods, profiles, or tubes
    • B21D7/12—Bending rods, profiles, or tubes with programme control
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D7/00—Bending rods, profiles, or tubes
    • B21D7/14—Bending rods, profiles, or tubes combined with measuring of bends or lengths

Definitions

  • the invention relates to a method for the mechanical bending of bars, in particular of tubes, with the features specified in the preamble of claim 1.
  • a method for the mechanical bending of bars, in particular of tubes with the features specified in the preamble of claim 1.
  • Such a method is as Wegumformungsbiegen or mandrel bending from the EP 0 384 477 B1 known.
  • the known method uses a machine in which a pipe to be bent is stored.
  • the known machine has a bending tool which is rotatable about an axis - the bending axis.
  • a tensioning device is part of the bending tool.
  • the tube to be bent can be clamped for the bending process.
  • the bending tool then has a lateral surface on the clamping device, which is a section of a surface of revolution. One end of this surface of revolution passes tangentially into the tensioning device.
  • the bending tool is pivoted about the bending axis by a predetermined angle.
  • the clamping device is also pivoted about the bending axis and pulls the pipe after it. So that the one end of the jig outstanding rear portion of the tube is not pivoted during pivoting of the clamping device, a bending support is provided, against which rests the rear portion of the tube.
  • the tube springs back slightly after bending, it is not sufficient to swing the bending tool by the bend angle provided for the tube, but the bending tool must be pivoted by an additional small angle, the overbending angle, in order to compensate for the springback of the tube that the tube after spring-back by the overbending angle exactly the desired bending angle (target bending angle) has.
  • the bending radius of the tube is determined by the curvature of the lateral surface of the bending tool and by the springback of the tube.
  • the springback has the consequence that the actual radius of the arc in the pipe is greater than the predetermined radius of the lateral surface of the bending tool.
  • the amount by which the actual bending radius is greater than the predetermined radius of the bending tool is referred to as the radius expansion. It depends above all on the material and the cross-sectional dimensions of the pipe, on the radius of the bending tool and on the bending angle and influences the dimensional accuracy of the bent pipe.
  • the dimensions of the bent pipe are specified by the bending task.
  • Decisive for the dimensional accuracy of a bent tube is the position of the two end points of the tube, the orientation of the end portions of the tube and the position of the intersections of the straight sections of the tube, which define in pairs an arc, namely the intersections of the center lines of the straight sections of the tube.
  • the location of the end points of the pipe and the pipe line intersection depends on the radius expansion.
  • the position of the pipe end points to each other moreover depends on the occurring in the course of the bending process extension of the Pipe off. This can be set to zero for the front pipe end, since the projecting before the first bending process on the jig straight pipe section - the front straight pipe section - undergoes no stretching.
  • the stretch affects the position of the back end of the tube by adding and extending the stretch that occurs in bending each individual arc across the tube such that the distance of the rear tube end from the straight line intersection associated with the last curved arc is, gets too big.
  • the WO 2007/121985 also discloses a method for machine-tensioning bending bars, in particular tubes, in which the bar is clamped in a tensioning device.
  • the tensioning device divides the rod into a front portion which is inserted in the tensioning device and optionally projects beyond it, and in a contrasting rear portion in which an arc is to be created adjacent to the tensioning device.
  • the tensioning device pulls the rear portion of the rod behind and along the bending stock against which the rod presses with the force required to bend. In this case, the length by which the rear end of the rod is pulled depends on the bending angle, the curvature of the bow and the extension of the rod.
  • a size is measured which is a measure of the caused by the Switzerlandumformungsbiegen radius expansion of the arc of the rod, while the rod is still in the bending machine.
  • This size or a derived quantity is stored in a computer.
  • the influence of the radius widening on the distance of adjacent straight line intersection points is compensated for each other if the bending task provides for a plurality of bends in the bar. If the bending task only provides for a single arc in the rod, then the influence of the radius expansion on the distance between the rod ends and the single rod straight-line intersection is compensated.
  • the bending task provides for a plurality of bends in the rod
  • not only the influence of the radius expansion on the distance of adjacent Straight line intersection points are compensated for each other, but also the distance between the rod ends and their adjacent straight line intersection points.
  • the compensation takes place in each case by adjusting the lengths of the straight bar sections provided between each two adjacent bends and / or by adjusting the length of the straight starting section of the bar and the length of the bar as a whole.
  • a straight line intersection is understood to be the intersection of the center lines of the two straight bar sections or pipe sections adjoining an arch. If the two straight bar sections or pipe sections are not in a common plane, then they do not intersect; In this case, the intersection of the projection of the center lines into a common plane is considered as a straight line intersection instead.
  • the distance between the end of the rod and the rod straight line intersection adjacent thereto is influenced not only by the radius widening but also by the elongation of the rod when bending each arc, which, together with the shortening of the bends resulting from the radius widening, causes For example, a rod that was trimmed for a given bending task, neglecting radius expansion and stretching, would be too long after being bent, and would not be truncated by the anticipated bow shortening and expected elongations of the rod.
  • the WO 2007/121985 A1 discloses several ways in which the influence of radius expansion and elongation of a rod or tube during bending can be taken into account in order to perform the actual bending task Dimensional stability of the bent rod or pipe to improve significantly. Details are in the WO 2007/121985 A1 disclosed. The revelation in the WO 2007/121985 A1 is hereby expressly incorporated into the present patent application.
  • rods or tubes can also be bent by free-form bending.
  • the EP 1 342 514 A2 discloses a machine for free-form bending.
  • free-form bending a rod or tube is moved through an array of at least three rollers, one roller of which can be approximated to the at least two other rollers. By approaching the one roller to the other rollers, it can be forced that there is no straight path for the rod or tube through the roller arrangement, so that a curvature of the rod takes place.
  • the advance of the rod or tube can be effected by driving one of the at least three rollers. However, it can also be provided a separate feed drive.
  • Freeform bending has the advantage that the curvature of the rod or tube can be changed continuously. Even when Freeformbiegen there is an elastic springback of the rod or tube and thus a radius widening, which depends on the bending behavior of the respective rod or tube and can lead to a length error of the bent rod or tube. Stretching of the rod or tube is however negligible in free-form bending in most cases.
  • the numerical values reflecting the bending behavior can be stored in the memory of a control unit of a bending machine and called up as required, and also automatically in a CNC bending machine.
  • pipes are often cut to a predicted length to be bent before being delivered.
  • certain pipe properties are assumed for the calculation of the length. If, however, during bending, it turns out that the pipe properties differ from the pipe properties assumed for the calculation of the pipe length, the calculated length to which the pipes are cut is too short, provided that their elongation and / or radius expansion during bending is smaller as accepted, or too long if the extension and / or radius widening is greater than assumed.
  • the stretching is caused by the tensile deformation bending, which is also referred to as tension-stretch bending or mandrel bending, and leads to elongation of the pipe depending on the pipe properties.
  • any stretching of the pipe or rod that may occur can be neglected in most cases.
  • a radius expansion assumed incorrectly in the calculation of the pipe length also leads to a length error of the pipe, both during mandrel bending and during free-form bending.
  • flanges are already welded to the ends of the pipes delivered for bending, or the pipes are crimped or turn out to be too short, then so far no suitable pipe could be bent, but a new pipe with corrected length had to be prepared. This is associated with considerable effort. Often you noticed the length error only after bending or only when installing the pipe in a plant. Then the cost of replacing a non-matching pipe is still significantly greater.
  • the present invention has for its object to provide a method according to which, in cases where it turns out that rods, in particular pipes, which are delivered in vorauszubeloter length for machine bending and in which then turns out that they are different when bending Behavior than assumed in the calculation, a correction of a length error can be done with less effort than in the prior art.
  • the invention is a method of mechanically bending bars, in particular tubes cut to a particular actual length, which precedes a desired shape of the bent bar resulting from a bending task under a false assumption of a particular bending behavior of the bar during bending was determined.
  • a nominal length of the rod is calculated, directly or indirectly, which is required in order to bend the rod in the desired shape.
  • This nominal length is compared with the actual length of the rod.
  • the deviation of the nominal length from the given actual length is reduced for the given rod in that in the bending task for the rod to be bent a deviating from the original desired shape shape is set, in which the distance between the two ends of the rod from each other and the orientation of the two ends of the rod relative to each other would deviate less from the originally desired shape than if the given rod having the actual length had been bent in accordance with the unaltered bending task.
  • An indirect calculation of the nominal length is understood to mean that their value does not necessarily have to be output numerically; it suffices if the predetermined bending behavior, characterized by numerically recorded parameters such as springback, radius expansion, extension and / or change of arc lengths, is satisfied by comparing the actual bending behavior original bending task can be modified so that given the actual length of the unbent rod a minimal, preferably vanishing, deviation of the position and orientation of the endpoints of the bent rod results from the originally required position and orientation of the endpoints of the bent rod.
  • the deviating from the desired shape shape is set so that the orientation and / or the distance of the ends of the rod relative to each other remain unchanged from the original desired shape.
  • the different shape is determined so that both the orientation and the distance of the ends of the rod remain unchanged.
  • the desired shape of a rod or tube is conveniently given by a bending task, which can be described by parameters as given in paragraph [0012] of this patent application. Taking into account the given, material-dependent bending behavior, it is possible from the bending task to calculate a nominal length which a rod or pipe should have, which is to be bent into a shape that is predetermined by the bending task. If the actual length of the rod or tube deviates from the desired length, the desired shape is modified according to the invention, ie, one or more parameters the bending task are changed so that the distance of the rod ends or tube ends from each other and their orientation are maintained relative to each other, as they have been formulated in the original bending task. Moreover, the bending task is modified so that the course of the rod or tube between its ends deviates from the originally intended course, preferably deviates from the originally intended course only within predetermined or preselected tolerance limits.
  • the bending task Prior to performing a bending task on a first bar from a batch, it is preferable to test on a sample bar from the same batch as the bar actually behaves during bending. If the sample bar behaves as assumed in calculating the actual length of the cut bars, then the bending task may be performed as originally determined. However, if the actual bending behavior deviates from the originally assumed bending behavior, the bending task is modified according to the invention, taking into account the deviation in the bending behavior that has been determined.
  • the stretch can z. B. from the bending angle ⁇ or from the radius expansion r a are derived.
  • the distance .DELTA.V by which the rear end of the rod is thereby moved forward, is easily obtained from the displacement sensor, which is assigned to the feed device for the rod.
  • the stretch can also be determined by means of the radius widening.
  • r a is the radius widening
  • ⁇ V is the distance that the trailing end of the rod was advanced as a result of the arc bending, measured before the spring recoil.
  • an expected change in the position of the bar end relative to the bar start can be conveniently determined in advance for each sheet. Since the overbending angle and the radius widening can already be determined during the first bending process or derived from the first bending process, with the help of the desired bending angle ⁇ and the desired bending radius R m , which are predetermined by the respective bending task, for each arc of Expected and according to the invention to be compensated and taken into account position errors for the rod end can be easily calculated. It has been shown that - if the stretch and the sheet shortening or free bending a sheet extension for a bending angle were determined - they can be easily calculated in relation to the bending angle for other bending angle.
  • the stretching and the bow shortening or bow extension are preferably standardized for a certain bending angle to a unit bending radius and normalized for a certain bending radius to a unit bending angle. From this, for a given bending task with a given bending radius R m and bending angle ⁇ , the expected absolute extension and the expected absolute arc shortening or arc extension can be calculated. In addition, it is possible to calculate beforehand the position at which the rear end of the bar should be after bending each individual arc of the bar.
  • the desired length of the rod or tube resulting from the material properties of the bars or tubes of a given batch for a specific bending task can therefore be calculated by the elongation determined during bending and / or by the radius widening determined during bending and / or by changing an arc length become.
  • the nominal length of the rod or tube can be estimated by comparing the elongation of the rod which occurred during bending and the arc shortening or elongation with that extension of the rod and with that arc shortening or elongation which corresponds to the calculation of the actual length. Length of the rod was used and / or by comparing the occurred during bending radius expansion with that radius expansion, which was used as the basis for calculating the actual length of the rod. If values of stretch or stretch factor or radius widening or bow lengthening or bow lengthening are known for tubes from different batches, the desired length of the rod for the current batch can be determined by interpolation or extrapolation.
  • the nominal length for a rod with a specific shape or for a specific bending task must advantageously be determined only once for bars from a particular batch and can then for all bars of the same batch and with the same bending task, because it is a reasonable assumption that the bars originating from the same batch behave equally when bent.
  • the method according to the invention can advantageously also be applied to each rod in particular such that when bending a first sheet or part of the first sheet, the relevant parameters characterizing the bending behavior are determined, and then taking into account the determined actual bending behavior, the remaining bending task on the rod is modified and done so that the layer the ends of the rod relative to each other and their orientation are as it dictates the original bending task.
  • the bending angle is changed in the rod.
  • a change of bending angles is particularly advantageous even when a rod is bent not only in one plane - then all bending axes are parallel to each other - but also when the rod is bent three-dimensionally, so that not all bending axes are parallel to each other.
  • the angle can also be changed with advantage, by which the bending plane is rotated, on which the bending axis is each senkrechet; in other words, to change the desired shape of the rod, the angle between two intersecting bending planes is changed, on each of which a bending axis is perpendicular.
  • the deviations in the course of a rod that result from a change in the bending task will be the smaller, the more the changes spread over the entire length of the rod.
  • the invention is therefore particularly suitable for bending tasks, in which at least two sheets are provided in a rod, and for such bending tasks, the inventive method is preferably used.
  • the more arcs are provided, the more arcs the changes in the bending task can be distributed and the less the changes in the individual arches and the shape of the overall shape of the rod will affect.
  • the desired shape of the bar is preferably changed by changing existing floors in the desired shape, in the case of a pipe, it is a pipe floor.
  • a pipe floor is understood to mean a pipe section in which an arc with a negative curvature follows a curve with a positive curvature.
  • the tube layers or Stäbe days are formed flatter than originally desired. As a result, the pipe section in which the respective floor is, slightly extended.
  • the pipe layers or Stäbe days are made steeper than originally planned, so that the pipe sections in which the pipe layers or Stager days are compared to original planning to be shortened. The same applies if arcs with positive and negative curvature follow one another in a bar.
  • the change of tube layers or Stages days is particularly suitable as a measure for carrying out the method according to the invention.
  • the invention is particularly suitable for the bending of pipes, but can also be applied to the bending of solid round bars, profile bars and hollow profile bars, which are referred to here together with tubes as bars.
  • the method according to the invention can be carried out both in a mandrel bending machine and in a machine for free-form bending.
  • a mandrel bending machine as used in the EP 0 384 477 B1 and in the WO 2007/121985 A1 is disclosed, for each arc to be bent in the rod, a front portion of the rod is clamped in a clamping device of a bending tool, which is pivotable about an axis.
  • a rear portion of the rod is applied to a bending abutment disposed in the vicinity of the bending tool.
  • the tensioning device is pivoted at a preselected angle and in such a direction that the respective rear portion of the rod is pulled and presses against the bending abutment. Belongs to the bending tool Mandrel about the peripheral surface of the rod is bent when the bending tool is pivoted.
  • An example of a machine for free-form bending discloses the EP 1 342 514 A2 ,
  • at least three rollers are provided, which are rotatable about mutually parallel axes.
  • the rod to be bent is passed between the at least three rollers so that a roller, which is also referred to as a bending template, is arranged on one side of the rod, while the remaining rollers are arranged on the opposite side of the rod.
  • a roller which is also referred to as a bending template
  • the remaining roles in the feed direction of the bar foremost role is also referred to as a bending role, the remaining roles serve as support rollers, which form an abutment for the rear portion of the rod. If more than one support roll is present, then they form a straight row.
  • the roller serving as a bending template approximates the connecting line between the bending roller and the first support roller and applies pressure to the rod so that it curves as it is pushed through the roller assembly.
  • the bending radius is the smaller the further the serving as a bending template role is advanced against the rod.
  • FIG. 1 shows as components of a mandrel bending machine in a plan view of a feed device 1, a bending support 2, which is designed as a linear slide rail, and a bending tool 3, which is pivotable about an axis perpendicular to the plane 4, the bending axis.
  • the bending tool 3 has a mandrel with a surface 5 designed as a surface of revolution, which extends over slightly more than a three-quarter circle and has a concave contour in the radial section, which is adapted to the outer diameter of the tube 6.
  • the rotation surface 5 passes tangentially into a tensioning device 7, consisting of a pair of clamping jaws, between which the tube 6 can be firmly clamped.
  • the tensioning device 7 is aligned parallel to the flexural deflector 2.
  • the bending abutment 2 is applied to the tube 6, which is inserted with its rear end up to a stop 8 in the feed device 1, which may be located on a feed slide.
  • the tube 6 is bent by pivoting the bending tool 3 with the clamping device 7. It pulls the rear portion of the pipe 6 along the bending stock 2 and winds the pipe 6 around the surface of revolution 5.
  • the required overbending angle .DELTA..beta. can first be determined with the aid of a measuring rule 9, which is coupled to the bending-resistant bearing 2. The determination of the excess bending angle ⁇ is given in EP 0 384 477 B1 described, to which reference is hereby made. If the overbending angle ⁇ is determined, then the pivoting angle of the bending tool 3 is increased by the overbending angle ⁇ in order to achieve the desired setpoint bending angle ⁇ 1 .
  • FIG. 1 shows the tube 6 in the over-arched state.
  • the rear end 6b of the tube 6 is a Weggeber information, which is coupled to the feed device 1.
  • the feed device 1 is withdrawn and decoupled from the end 6 b of the tube 6.
  • the bending support 2 is retracted transversely to the rear leg of the tube 6 parallel to itself and allows a springing of the bow 6a.
  • This state shows the FIG. 2 ,
  • the arc 6a of the tube 6 is now tension-free, its radius has widened.
  • the angle between the two tube legs has increased and is now 180 ° - ⁇ 1 .
  • the bending tool 3 is pivoted to move the rear leg of the tube 6 in alignment parallel to its original orientation as in FIG. 1 and to bring parallel to the bending stock 2.
  • This state shows the FIG. 3 , In the FIG. 3 In addition, the location is shown, the rear pipe legs in the state as in FIG. 1 would have.
  • the rear end 6b has shifted by the distance ⁇ V 2 in the direction against the feed device 1.
  • This displacement can be measured by means of the displacement sensor, which is coupled to the feed device 1 by the feed device 1 is advanced to the stop against the end 6b of the tube 6 and this in the same reference position - stop 8 - receives, which it FIG. 1 had held.
  • ⁇ V is the shortening of the feed to be considered.
  • a change in the bending behavior of the rod compared to the originally assumed bending behavior will lead to a change in the radius widening during bending by a certain angle ⁇ in the case of mandrel bending and also lead to a change in the radius widening or directly to a change in the radius of the arc during free-form bending. if one leaves the arrangement of the rollers acting on the rod during bending relative to one another unchanged relative to the original bending task.
  • the enlargement or reduction of the bending radius which accompanies both cases leads to a shortening or lengthening of the arc compared with the original bending task, if the bending angle ⁇ is maintained, which at the same time determines the position of the ends of the bent rod relative to the specification of the original bending task changes if the change in the arc length is not compensated using the method according to the invention.
  • the compensation can be done by changing the bending angle and / or the bending radius with respect to the original bending task in the case of further bends in the rod so that in any case, the ends of the finished bent rod receive the prescribed in the original bending task position and orientation relative to each other.
  • a changed shape of the rod or changed parameters of the bending task can be calculated in a control unit of the bending device by a mathematical algorithm.
  • the calculation is carried out according to the invention under the boundary condition that the position of the ends of the bent rod relative to one another and the orientation of the ends relative to one another remain unchanged relative to the original bending task.
  • the shape of the bent rod may deviate from the original desired shape, but preferably only within tolerable limits, which can be kept smaller, the more sheets and in particular the more floors are provided in the bent rod.
  • FIG. 4 shows by way of example a characteristic curve 10 which represents the dependence of the radius widening on the bending angle for a selected tube.
  • ⁇ On the horizontal axis of the bending angle ⁇ is specified.
  • the radius expansion r a On the vertical axis, the radius expansion r a is given in relative units.
  • the curve is intended to represent only schematically a typical course of the characteristic. It is a falling characteristic, which has similarity to a hyperbola.
  • the dependence of the radius widening r a on the bending angle ⁇ can be simplified by linearizing the characteristic curve 10 in three sections 11, 12 and 13 by dividing the characteristic curve 10 in the range from 0 ° to 60 ° by a steeper straight line 11 is approximated, is approximated in the range of 60 ° to 120 ° by a less steep line 12 and is approximated in the range of 120 ° to 180 ° by a very flat straight line 13.
  • the linearized characteristic may be stored in the control of a tube bending machine, so that the controller can access it during bending. For different tubes or rods, individual characteristic curves are expediently stored in a linearized form.
  • FIG. 5 schematically shows the shape of the shape of a bent bar 14, which has two floors 17 and 18 between its two ends 15 and 16. It is assumed that when calculating the length of the rod one too low As a result, the rod, when bent according to the original bending task, has a distance ⁇ L too short between its two ends 15 and 16. To compensate for this error .DELTA.L, the two floors 17 and 18 are made somewhat flatter by changing the bending angle, as in FIG. 5 - Exaggerated for the sake of clarity - shown in phantom. The deviations between the two courses of the bar should be within tolerable limits.
  • FIGS. 6 and 7 show in a side view and in plan view the shape of a rod to be bent at right angles.
  • the right angles should be bent with a radius of 100 mm.
  • the radius is in the FIGS. 6 and 7 not shown. Rather, the rod is shown simplified only by its straight line and its intersections (in the case of a pipe through its pipe line and their intersections).
  • the bar start point 20, the straight line intersection points 21, 22 and 23 and the bar end point 24 are indicated in their coordinates X, Y and Z of a rectangular coordinate system in the following Table 1 in mm.
  • a rod length of 1,831.24 mm was calculated with an assumed yield factor of 0.920 and an assumed radius expansion of 1.0 mm. At this length, the rod was cut off before bending. For the subsequent bending, therefore, the actual length is 1,831.24 mm.
  • the front end 21 of the rod was positioned 199 mm in front of the center of the mandrel in the bending tool 3.
  • the further coordinates would have the coordinates given in Table 2 due to the elongation and radius expansion measured in the first arc, if the bending task were carried out as originally planned, ie without application of the method according to the invention.
  • the result would be that the end point 24 of the bent bar would deviate by 10 mm in the direction of the X coordinate and by 1 mm in the direction of the Z coordinate from the planned position:
  • FIGS. 8 and 9 show in a schematic representation according to the FIGS. 6 and 7 the actual bending achieved with the application of the invention.
  • the given from the original bending task on the basis of the originally assumed bending behavior given shape (as in the FIGS. 6 and 7 ) is in the FIGS. 8 and 9 shown in dashed lines.
  • the slightly different shape of the bent using the invention bar is shown in solid lines. After carrying out the method according to the invention, the bar has the following bending angles:

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Bending Of Plates, Rods, And Pipes (AREA)
EP20090013213 2008-10-20 2009-10-20 Procédé de cintrage mécanique de barres, notamment de tuyaux Withdrawn EP2177288A2 (fr)

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DE102008052474A DE102008052474A1 (de) 2008-10-20 2008-10-20 Verfahren zum maschinellen Biegen von Stäben, insbesondere von Rohren

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EP2177288A2 true EP2177288A2 (fr) 2010-04-21

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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106391784A (zh) * 2016-09-29 2017-02-15 哈尔滨建成集团有限公司 一种手动细圆钢两端弯半圆装置
CN114713677A (zh) * 2022-03-04 2022-07-08 中国船舶重工集团公司第七二五研究所 一种大直径钛合金弯头的成形方法
DE102021206031A1 (de) 2021-06-14 2022-12-15 Porta Gestelltechnik Koppe GmbH & Co. KG Lackiergestell und Verfahren zu dessen Herstellung

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0384477B1 (fr) 1989-02-23 1994-08-10 Rasi Maschinenbau Und -Handels Gmbh Procédé et machine de pliage de tubes
EP1342514A2 (fr) 2002-03-06 2003-09-10 Rasi Maschinenbau Und -Handels Gmbh Dispositif pour detecter un angle de cintrage d'un anneau, et procédé de régulation d'une cintreuse
WO2007121985A1 (fr) 2006-04-24 2007-11-01 Rasi Maschinenbau Gmbh Procédé de cintrage sous traction mécanique de barres, en particulier de tubes

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