Classifications

• • 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
  • B21D7/08—Bending rods, profiles, or tubes by passing between rollers or through a curved die

Definitions

• the invention relates to a bending device with pendulum rolling rollers according to the preamble of claim 1.
• the invention discloses a new bending method, which is also referred to below as cold flow form bending.
• a four-roll bending machine is equipped with a mandrel shaft which is positioned in the interior of the profile in the bending zone.
• the bending machine consists of a center roller bearing on the inside of the curved profile, a rolling roller resting on the outside of the arch and a bending roller arranged on the outlet side of the profile, which acts on the outside of the arch, against the supporting action of one on the inlet side on the outside of the arch support roller.
• Stretching and upsetting are events that result from the application of force to overcome the section modulus of a section to be bent; these forces cause a material flow in the section to be bent.
• the stretching and upsetting flow is caused by large tensile and compressive forces in the outside and inside of a profile sheet production when the elastic limit is exceeded.
• micro or macro crack formation could occur in the side wall of the curved profile, or shear forces at the transitions between rolled and unground walls, which could result in separation of the material.
• the homogeneity of the structure was disturbed or even interrupted.
• the invention is therefore based on the object of developing a bending device of the type mentioned in such a way that an optimal shaping of a profile is achieved without disturbing the homogeneity of the structure while avoiding micro or macro crack formation in the side walls of the profile.
• the invention is characterized by the technical teaching of the claim.
• pendulum rolling rolls are arranged, which act on the upper and lower side walls of the profile.
• the homogeneity of the material during the bending process is largely maintained or is even improved by the compression according to the invention of all walls (outside of the arch, inside of the arch, top side wall and bottom side wall).
• the invention accordingly proposes further rollers which bear against the upper and lower side walls, which are referred to below as oscillating roller rollers.
• the invention is not restricted to the term "pendulum roller".
• these rolling rolls (with or without a contour) are arranged in a non-oscillating manner, but rather rigidly.
• the invention is primarily concerned with the induced structure flow that runs from the outside of the profile to the inside of the profile and controls this flow by attaching upper and lower roller rollers to the upper and lower side walls so as to redirect the flow from the outside of the arch to the inside of the arch and initiate there.
• volume shift causes a longitudinal flow with the consequence of an elongation above the bending line.
• an arch-shaped profile that lies in the XY plane results after the bending process. It is defined by an outer side of the sheet and an inner side of the sheet, the so-called rolling roller being in contact with the outside of the sheet, while the so-called center roller is in contact with the inside of the sheet.
• the profile on the outside of the curve is lengthened by the dimension l + ⁇ I, while the length I remains on the inside of the curve. This applies in the event that the bending line is on the inside of the sheet. This means that the entire profile cross-section is rolled out from the inside of the bend.
• the material is elongated, along with a controlled flow of material in length, so as to produce the outside of the sheet.
• end walls The walls extending perpendicularly thereto are referred to as "side walls”.
• the invention is now concerned with the material flows which arise in the end wall on the outside of the bow and which, according to the invention, are deflected via the novel pendulum rolling rollers, which act on the side walls, over the associated side walls up to the end wall on the inside of the bow.
• the cross-section can be laid so that the compression area on the inside of the profile arch is largely eliminated due to the corresponding cross-sectional changes based on the previously described and calculated material shifts on the profile wall. There are therefore no longer any compressive forces that can cause deformation. Such laying of the bending line is achieved by rolling out on the side walls. For this reason, this process is also known as roll bending.
• the upper and lower oscillating roller rolls are tapered in their axial position against the plane parallelism of the profile to be bent. A greater rolling depth is therefore achieved on the two upper and lower side walls on the outside of the sheet than is comparatively on the inside of the sheet.
• the adjustment of the axial position of the two upper and lower spherical rollers is therefore such that the spherical rollers on the upper and lower side wall on the outside of the arch have a relative depth of penetration into the material, whereas this depth of penetration towards the inside of the arch can be set to 0.
• the invention is not limited to the elimination of the bending roller. It can also be provided that the bending roller is still present and that the pendulum rolling rollers according to the invention which are provided here and which act on the upper and lower side walls of the profile are additionally present.
• the bending line is laid on the inside of the arch and this induces a structure flow from the outside of the arch towards the inside of the arch. This is achieved by means of differently adjustable axial longitudinal angles of the pendulum roller and their depth of penetration into the material to be formed.
• the depth of penetration of the roll (roller roll) lying on the outside of the sheet is taken up by the pendulum rolling rolls lying perpendicularly to it and acting on the side walls and diverted into the side walls and passed over the side walls to the inside of the sheet.
• rollers should therefore, if possible, enclose the profile to be formed in a form-fitting manner in order to avoid evasion, bulging and the like in this gap area.
• the pendulum roller In order to achieve this effect, it is necessary from a mechanical engineering point of view to design the pendulum roller to be displaceable in its longitudinal axis, so that it follows the profile to be formed during the bending process.
• the invention is not limited to the fact that in the case of so-called roll bending, only the pendulum rollers resting on the side walls are conically set against one another.
• the rolling and center rollers which bear against the inside and outside of the arch are designed to be commuting accordingly and can accordingly also be used against one another.
• the bending line With this gravity bending, the bending line remains in the gravity line, i.e. H. approximately in the middle of the profile to be bent if it is a symmetrical profile.
• the upper and lower pendulum rolling rollers which are in contact with the upper and lower side walls, can either be placed at an angle to one another, or that they have a double conical running surface.
• Gravity bending describes a state of bending in which the profile is thinned and elongated beyond the neutral line, i.e. the line of gravity, by stretching and elongating the wall thickness beyond the line of gravity.
• the wall thickness begins to increase with volume, which has been displaced from the gravity line to the outside of the arch.
• the line of gravity i. H. the center of gravity shifts by the dimension X towards the inside of the arch; caused by the material volume shift.
• the internal profile cross section is largely preserved by the mandrel shank tool.
• This knowledge forms the basis for the volume calculation to determine the various roll penetration depths on the profile walls and the radii of a profile to be bent that can be adjusted in a controlled manner.
• the pendulum rolling rollers are now adjusted in accordance with the physical displacement phenomena mentioned above and the volume changes in the end and side wall area calculated from this.
• a highly ductile structure i.e. no distortions, micro or macro cracks in the structure.
• Clean outer and inner contour of the profile cross-section i.e. no warping, bulges, corrugations in the profile wall.
• upsetting roll bending is described in more detail as a third embodiment of the invention.
• upper and lower pendulum rolling rollers are present, in connection with a bending roller arranged axially offset from the aforementioned rollers.
• the bending line is moved to the outside of the arch and the conical material thickening of the side walls is deflected into the inner wall of the arch.
• the main upsetting forces arise on the inner wall of the arch by shortening the sheet processing.
• the upsetting roll bending uses opposed, braked center and roll rolls, i. that is, the speed of the respective roll on the inside and outside of the profile is lower than the speed of the profile through the bending gap.
• brake shoes are arranged on the inside and outside of the bend, which increase the resistance to the profile to be bent and thus create a strong compression effect in the bending axis.
• the internal geometry (this is the internal cross-sectional shape) of a profile remains unchanged in terms of dimensions. It is important that the internal dimensions of the profile are maintained and only the external dimensions of the profile are changed in the sense of a volume shift. The inside dimension of the profile remains constant.
• the bending line is the line on which the forces for stretching and upsetting build up and deform the corresponding profile.
• the present invention is not only directed to a two-dimensional shaping of a profile, but that it can additionally be achieved with the arrangement of either contoured or oscillating rolling rollers that a helix (in three-dimensional shape) can be bent.
• a helix in three-dimensional shape
• the present invention is not only directed to a two-dimensional shaping of a profile, but that it can additionally be achieved with the arrangement of either contoured or oscillating rolling rollers that a helix (in three-dimensional shape) can be bent.
• a helix in three-dimensional shape
• the upper and lower pendulum roller rolls are still used for this purpose for the desired structural flow and for the radius of the bend.
• FIG. 2 the deformation of a profile during the bending according to FIG. 1 if there is no mandrel shaft carried in the bending zone;
• Fig. 4 Section along the line A-A in Figure 3;
• Fig. 6 the enlarged view of the profile to be bent under the influence of the various rollers during roll bending
• Fig. 8 section along the line A-A in Figure 7;
• Fig. 11 Section through the bending roll zone of the profile with the four adjacent rolls
• Fig. 12 Schematic representation of the forming processes in section
• a symmetrical hollow profile (referred to as profile 1) is formed into a bent profile by symmetrical bending.
• roller roll 4 rests on the outside of the sheet (outer end wall), while a middle roll 3 rests on the inside of the sheet (inner end wall).
• the two rollers are either both or only one of the two is driven in rotation.
• a mandrel rod 7 In the interior of the hollow profile runs a mandrel rod 7, at the front end of which a mandrel shaft 8 is arranged, which has corresponding support elements 9, 10.
• These support elements 9, 10 are highly wear-resistant support bodies which rest on the inside of the profile 1 in the region of the bending zone.
• the bending zone is formed by the juxtaposition of the central rollers 3 and 4.
• FIG. 1 shows that the roller 4 rests on the outside of the sheet 53, while the middle roll 3 rests on the inside 52 of the sheet. It is thereby achieved that, for example, the inside of the arc is bent with a bending radius 15, while the outside of the arc 53 is bent with a bending radius 14.
• a bending roller 11 is arranged on the outside of the arch 53 at an axial distance from the bending zone, which can be moved into the position 11 'as shown so as to act with an adjustable force on the outside of the arch 53 of the profile to be bent ,
• the bending roller 11 acts in principle against the resistance of the support rollers 5, 6, in particular the support roller 6, while the support roller 5 has only management tasks.
• an upper pendulum roller 12 bears in a shaping manner on the upper side wall 50, while a lower pendulum roller 13 bears in a shaping manner on the lower side wall 51.
• these two oscillating rolling rollers 12, 13 are designed to oscillate in their axial position (with respect to the horizontal axis 21), i. H. the upper pendulum roller 12 can be pivoted in the arrow direction 18 on the pivot axis 22a and the lower pendulum roller 13 can be pivoted in the arrow direction 19 on the lower pivot axis 22b.
• the depth of penetration on the outside of the sheet 53 is at a maximum, while it runs towards 0 on the inside of the sheet 52.
• the upper pendulum roller 12 is pivoted clockwise in the direction of arrow 18 against the upper side wall d 50, while the lower pendulum roller 13 is pivoted counterclockwise (arrow direction 19) against the corresponding side wall 51.
• FIG. 2 now shows that if the profile is reshaped when the corresponding guide means are removed, the profile 1 ′, which is undesirably deformed, results from a profile 1, which undergoes a corresponding indentation on the outside 53 of the arch with a corresponding reduction in the width dimension, whereby a simultaneous thinning of the material takes place.
• FIG. 5 shows the profile deformation on an enlarged scale during gravity bending.
• the respective rollers 3, 4, 12, 13 are only shown in a hint, and only in the area of their running surfaces when they act on the respective outer sides of the profile 1 to be formed.
• the transfer of the drawing figure 5 to the drawing figure 1 means that practically from the drawing plane of FIG. 5 the profile is bent upwards in the direction of arrow 26.
• roller 4 is fed into the outer sheet 29 in the direction of arrow 46 (feed direction).
• the bending axis 54 runs through the zero line 30.
• the previous, undeformed outer arch 29 transforms into the deformed outer arch 29 '. This is connected to a material thinning 43.
• Material thinning 43 results from the difference between the undeformed outer arch 29 and that which results after the bending Outer arch 29 '.
• the stretching forces that arise during the forming process result in said material thinning 43.
• This wedge-shaped material thinning 31 disappears on the bending axis 54 in the region of the zero line 30.
• the tread 25 of the respective pendulum roller 12, 13 is chamfered in such a way that the tread part 25a rises conically from the bending line 30 to the outer curve 29.
• a maximum penetration depth of the pendulum rolling rollers 12, 13 acting in the outer curve is thus achieved. This depth of penetration supports arch elongation, i.e. H. the increase in length on the outside 53.
• the center roll 3 has only a shaping character in such a way that the profile of the inside 52 of the arch is only supported accordingly.
• the resulting increase in material 44 results from the volume shift from the two wedges of the increase in material 32 occurring in the side wall.
• Decreasing means that they are indicated with a plus on the inner arch 28 and are therefore maximum.
• a stretching force therefore arises on the outside of the arch, while a compression force arises on the inside of the arch.
• the thinning 27a that arises on the outer arch 29 is consequently converted into the same size in the compression thickness 27 on the inner arch 28.
• the pendulum rolling rollers 12, 13 do not have a specially contoured running surface 25, but that the pendulum rolling rollers 12, 13 are chamfered by an angle 45 (angle ⁇ ) overall, namely from the outer curve 29 in the direction of the inner arch 28.
• the bending line now shifts from the center of gravity in the central axis 23 in the direction of the bending line 30 to the inner arch 28.
• the center roll 4 is advanced in the direction of the arrow 46 (infeed direction) against the outer sheet 29, which results in a thinning of the material 43 and this thinning 43 is converted into an increase in length on the outer sheet 29.
• the material thinning 43 in the area of the side walls is converted into a wedge-shaped material thinning 31, which runs out towards the inside of the arch 28 on the inner arch 28.
• the bending line 30 is located on the inner side of the inner bend 28.
• the surface pressure of the roller 4 on the outer sheet 29 is approximately three times higher than the surface pressure of the center roll 3 resting on the inner sheet 28. This results in a penetration depth of z. B. 4 mm in the area of the outer sheet 29 and to a penetration depth of 1, 3 mm in the area of the inner sheet 28 for the corresponding rollers 4th, 3rd
• the embodiment according to FIG. 6 is thus characterized in that the upper pendulum roller 12 is tapered relative to the lower pendulum roller 13, so that a greater depth of penetration of these two pendulum rollers 12, 13 takes place on the outer bow 29 than on the inner bow 28.
• the penetration depth is 0 on the inner bend 28, where the bend line 30 runs.
• the entire bending process takes place in the bending axis 54.
• the action force of the roller 4 is consequently transmitted to the central roller via the profile and the mandrel shaft 8 held in the interior of the profile.
• the pendulum rolling rollers 12, 13 are fed against the corresponding side walls 50, 51 of the profile with an adjustable feed force, this feed force being in the range of 100 kN.
• the feed force of the roller 4 on the outer sheet 29 could be in the range of 400 kN, while the center roller 3 only experiences a reaction force.
• the center roll 3 takes up a total of 800 kN.
• FIG. 7 shows a second exemplary embodiment of a pendulum roller roll bending machine, which describes the upsetting roll bending.
• FIG. 7 additionally shows that a link chain 39 is arranged at the front free end of the mandrel shaft 8, which links individual roller elements 40 to one another in an articulated manner.
• roller elements 40 are arranged in the region of the bending axis 54 and in the outlet direction behind the bending axis 54 in order to additionally support the inner cross section of the profile V.
• a strong compressive force arises from the fact that the profile is pushed into the bending zone in the direction of arrow 2 and the speed at which the central roller 3 and the roller roller 4 drive the profile 1 is lower than the pushing speed in the direction of the arrow 2 one Squeezing effect on profile 1, which is additionally supported by two opposing brake shoes 37, 38.
• the brake shoe 37 bears against the outside of the bow 53, while the brake shoe 38 bears against the inside of the bow 52.
• FIG. 8 further shows that not only are the pendulum rolling rollers 12, 13 designed to be pivotable, but that it is also possible to also design the center roller 3 and the roller 4 to be pivotable.
• the latter rollers 3, 4 are then designed to be pivotable when not only a two-dimensional bending of the profile 1 is required, but when this profile is to be bent in a helical shape. This is symbolized by the arrow directions in FIG. 8.
• FIG. 9 shows a section in the direction of line B-B in FIG. 7, where it can be seen that the brake shoe 38 is applied to the inside of the bow 52 to increase friction and thereby achieve a strong compression effect.
• the bending line 30 is now laid on the outer curve 29.
• the bending line 30 is understood such that no force acts on the profile 1 in this area. Accordingly, it is a neutral line.
• the previously undeformed inner arch 28 is positioned radially outward in the direction of the inner arch 28 ', as shown in FIG. 10.
• this volume corresponds exactly to the volume of the material increase 32 'in the region of the inner curve 28'.
• the tread 57 of the center roller has only a shaping character in order to form the enlarged inner arch 28 ".
• the increase in material 48, 32 'on the inner arch 28 does not interfere with the use of such a profile.
• Such upsetting roll bending is used when the statics of the bent profile make it necessary to keep the wall thickness of the outer curve 29 and the wall thickness of the side walls 50, 51 the same even after the forming.
• the increase in the wall thickness in the area of the inner arch 28 is harmless and increases the section modulus of the curved profile.
• FIGS. 11 and 12 show an exemplary embodiment of roll bending with volume shift using the example of a square tube 200 x 200 x 20 mm:
• the bending line lies on the inner curve, i.e. the development length does not change.
• the side walls are rolled symmetrically from the outside 4 mm inwards to 0.
• This elongation on the inside is canceled out by the bending roller via upsetting.
• the penetration depth is denoted by 60 and the rolling depth by 61 in FIG.
• the amount of penetration depth on the inlet side is designated by 60, while the amount on the outlet side (opposite in sign) is designated by 60 '.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Bending Of Plates, Rods, And Pipes (AREA)
• Metal Rolling (AREA)
• Rolls And Other Rotary Bodies (AREA)

Applications Claiming Priority (2)

Publications (1)

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• 2004
  • 2004-01-24 DE DE102004003681A patent/DE102004003681A1/de not_active Ceased
• 2005
  • 2005-01-11 CA CA002553737A patent/CA2553737A1/en not_active Abandoned
  • 2005-01-11 CN CNA2005800030839A patent/CN1909990A/zh active Pending
  • 2005-01-11 KR KR1020067017095A patent/KR20060126791A/ko not_active Application Discontinuation
  • 2005-01-11 JP JP2006549959A patent/JP2007518570A/ja not_active Withdrawn
  • 2005-01-11 WO PCT/EP2005/000161 patent/WO2005070580A1/de active Application Filing
  • 2005-01-11 MX MXPA06008167A patent/MXPA06008167A/es not_active Application Discontinuation
  • 2005-01-11 RU RU2006130468/02A patent/RU2349405C2/ru not_active IP Right Cessation
  • 2005-01-11 EP EP05700799A patent/EP1706227A1/de not_active Withdrawn
  • 2005-01-11 US US10/587,031 patent/US20080257004A1/en not_active Abandoned

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