EP0679456A1 - Device for measuring a bending angle in a programmable sheet bending brake - Google Patents

Device for measuring a bending angle in a programmable sheet bending brake Download PDF

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Publication number
EP0679456A1
EP0679456A1 EP95200994A EP95200994A EP0679456A1 EP 0679456 A1 EP0679456 A1 EP 0679456A1 EP 95200994 A EP95200994 A EP 95200994A EP 95200994 A EP95200994 A EP 95200994A EP 0679456 A1 EP0679456 A1 EP 0679456A1
Authority
EP
European Patent Office
Prior art keywords
blade
bending
angle
edge
sheet
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.)
Ceased
Application number
EP95200994A
Other languages
German (de)
English (en)
French (fr)
Inventor
Renato Montecchio
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.)
Salvagnini Italia SpA
Original Assignee
Salvagnini Italia SpA
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Salvagnini Italia SpA filed Critical Salvagnini Italia SpA
Publication of EP0679456A1 publication Critical patent/EP0679456A1/en
Ceased legal-status Critical Current

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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
    • B21D5/00—Bending sheet metal along straight lines, e.g. to form simple curves
    • B21D5/04—Bending sheet metal along straight lines, e.g. to form simple curves on brakes making use of clamping means on one side of the work
    • B21D5/045—With a wiping movement of the bending blade

Definitions

  • the present invention relates to a device for the measurement of an angle of bending of an edge of a polygonal sheet of metal and for the automatic correction of errors of bending, particularly for a machine for programmable bending on all the sides of the sheet.
  • the sheet of metal is originally available in strips wound in coils. According to the quantity of like pieces that it is required to manufacture with the sheet metal, the transformation process is different. If the quantity of like pieces to be produced one after the other is relatively small, and this is the case to which the present invention refers, the first operation of the transformation process is the transversal division of the strip into sheets of the maximum length compatible with the method of transport and with the dimensions of the machines that continue the transformation process.
  • the length of the sheets that are obtained from the strip with the first shear is selected as long as possible so as to constrain the subsequent shears as little as possible and to allow each sheet to be subdivided with a minimum of scrap.
  • the bent edge of the sheet metal does not maintain exactly the inclination that has been given to it by the bending machine, but it springs back to a smaller inclination; this final inclination of the bent edge, for an equal inclination caused by the machine, can be different from sheet to sheet due to the small differences in thickness and crystalline structure; the final inclination of the bent edge can also be different from one side to the other of the same sheet due to the different crystalline structure on sides that are parallel or orthogonal to the direction of lamination.
  • the object of the present invention is that of taking away from the operator of the machine the task of measuring the angles of bending at the start of the production of a lot and of introducing into the programme being executed the appropriate corrections, suitable for containing within the ranges of tolerance the errors of bending of all the pieces of the lot subsequent the first.
  • a device for the measurement of an angle of bending of an edge of a polygonal sheet of metal particularly for a machine for programmable bending on all the sides of the sheet, said machine comprising a supporting structure having a substantially C-shaped transversal cross-section, a fixed lower counterblade and an upper blank holder vertically movable, both supported by said supporting structure, a blade holder having a substantially C-shaped transversal cross-section, in turn movably supported by said supporting structure, and at least one bending blade rotatably supported by said blade holder and cooperating with said counterblade and said blank holder for bending one edge of said sheets of metal in a programmable manner, characterized in that said bending blade is operationally connected to actuating means apt to bring it, without thrust, against said bent edge and to detecting means apt to measure the angle of rotation of the blade.
  • said detecting means are operationally connected to means for adjusting the angle of bending of said edge to automatically correct errors of the angle of bending, so that they remain within predetermined ranges of tolerance.
  • the device according to the invention allows an improvement to be made in the quality of the pieces produced and reduces machining times, because it is sufficient to measure the angle of bending of the first machined sheet and, in case of error, to introduce the necessary correction into the bending machine, so that the following sheets of a lot are machined with the prescribed angle of bending.
  • a programmable bending machine that comprises a base 1 having a substantially C-shaped transversal cross-section, provided with guides (not shown), wherein a piston stem 50 causes a blank holder 5 to slide vertically, that, by pressing up against a fixed counterblade 6, clamps a sheet of metal 7 having a polygonal shape. An edge 8 of the sheet 7 has been bent along a "line of bending" defined by active edges of the counterblade 6 and of the blank holder 5.
  • the base 1 is also provided with guides 60 on which further piston stems 51 cause to slide vertically a blade holder 2, also having a substantially C-shaped transversal cross-section.
  • the blade holder 2 there are rotatably supported, by means of a hinge 12, a lower blade 3 and, by means of a hinge 52, an upper blade 4, that are used for the automatic, programmable bending on all the sides of the sheets 7.
  • the blade 4, above the sheet 7, generates downward bends, and the blade 3, below the sheet, generates upward bends.
  • the two blades 3 and 4 are hinged on the blade holder 2 with an axis parallel to the line of bending of the sheet 7 and, together with the blade holder, they perform a movement of translation in a direction orthogonal to the plane in which the undeformed sheet metal lies. With this first movement, one or the other blade, 3 or 4, engages with the edge 8 and carries out a bending of a pre-set angle along the entire length of one side of the sheet.
  • FIG. 2 There is shown in Fig. 2 one of a series of simple-acting hydraulic cylinders 13 that, operating on a protrusion 14 of the lower blade 3, keep the latter, at rest, against a wedge-shaped spacer 15, as shown in Figs. 2 and 4.
  • An active edge 16 of the lower blade 3 is thus at a predetermined distance from the active edges of the counterblade 6 and of the blank holder 5 depending on whether the wedge-shaped spacer 15 is inserted to a greater or lesser extent, by means of a double-acting longitudinal positioning hydraulic cylinder 53 (Fig. 4).
  • the initial angular position of the lower blade 3 is adjusted, in relation to the thickness of the sheet metal and of the radius of curvature that is desired along the bend, by means of the longitudinal displacement of the wedge-shaped spacer 15.
  • a succession of simple-acting hydraulic cylinders 19 operate, during the bending step, on the lower blade 3 through a planar-spherical pad 20 and a wedge-shaped spacer 18.
  • the final angular position of the blade 3 and thus the angle of bending of the edge 8 depend on the longitudinal position of the wedge-shaped spacer 18.
  • the cylinders 19 push the blade 3 against the edge 8 of the sheet 7, causing the edge of the blade to perform a motion that is almost parallel to the plane of the sheet.
  • To this second movement of the blade 3 there corresponds a motion of rotation of the edge 8 around the line of bending and a further bending of the edge 8 along the entire length of one side of the sheet 7.
  • the action of bending of the edge 8 ends when expansions 21 of pistons 22 of the cylinders 19 come against abutments 23.
  • the longitudinal position of the wedge-shaped spacer 18 is determined by a double-acting longitudinal positioning hydraulic cylinder 54.
  • a pair of simple-acting hydraulic cylinders 17 cause the cylinders 13 to move back, after having been discharged, and separate the blade 3 from the wedge-shaped spacers 15 and 18, to allow the longitudinal displacement of the spacers themselves, without the resistance due to the friction with the blade.
  • the wedge-shaped spacers 15 and 18, after the blade 3 has been pushed away by the cylinders 17, are brought to the positions corresponding to the start and to the end, respectively, of the operating stroke of the blade 3.
  • the blade holder 2 moves upwards causing the active edge 16 of the blade 3 to interfere with the edge 8, that thus starts to be bent; the cylinders 19 push the blade 3 to the end of the bending stroke, while at the same time causing the cylinders 13 to move back and lastly the cylinders 13 cause the blade 3 to return to the initial position, while at the same time causing the cylinders 19 to move back.
  • the blade 3 performs two distinct motions, that take place simultaneously or in succession, one of translation in a direction orthogonal to the plane in which the undeformed sheet metal 7 lies, thus vertical, and one of rotation around the hinge 12 parallel to the line of bending, to which there corresponds a motion of the edge of the blade that is almost parallel to said plane.
  • the upper bending blade 4 is, except for the edge that is in contact with the sheet 7, symmetrical with respect to a median plane parallel to the plane of the undeformed sheet metal 7 and executes symmetrical movements under the control of means similar to those just described for the lower blade 3.
  • the machine bends the edge 8 of the sheet 7 by an angle and radius that are programmable (programmable by means of the displacements of the two wedge-shaped spacers 15 and 18).
  • the angle of bending of the edge 8 is determined by the longitudinal position of the wedge-shaped spacer 18.
  • an arm 35 is fastened to one end of the lower blade 5.
  • a double-acting hydraulic cylinder 39 is hinged at 46 to the arm 35 and at 47 to the blade holder 2.
  • the arm 35 ends with a sector gear 36, which, through a pinion 37, drives an encoder 38.
  • the cylinders 13 do not operate and the hydraulic cylinder 39 operates the arm 35 first to discharge the oil from the cylinders 19 and to separate the blade 3 from the edge 8. Then the cylinder 39, inverting its motion, operates the arm 35 to move the active edge 16 of the blade 3 delicately towards the bent edge 8.
  • the number of impulses issued by the encoder 38 indicates the angular position of the blade 3, from which the angle of bending of the edge 8 is deduced with an experimentally determined algorithm that takes into account the thickness of the sheet metal and the position of the blade during the motion of the blade holder. From the information provided by the encoder 38 the error of bending due to the spring-back of the sheet metal is deduced.
  • the value detected of the angle of bending is compared with a design value and, in case of deviations, the hydraulic cylinder 53 intervenes to displace the wedge-shaped spacer 18 and to adjust the final angular position of the blade 3, so that the angle of bending of sheets 7 following the first remains within the prescribed ranges of tolerance and the errors of bending detected on the first sheet are corrected.
  • the same can take place for the upper blade 4, if it is provided in a similar manner with an angle measuring device like the one just described.
  • the angle measuring device can be limited to the lower blade.
  • the blade rest then delicately on the edge 8 of the sheet that has just been bent and still held by the blank holder 5 and by the counterblade 6. With this delicate contact, that does not move the bent edge 8 from its natural position, the blade assumes an angular position that is univocally linked with the angle of bending through an algebraic relation that, as already said, is determined experimentally.
  • a sufficiently accurate reading of the angle of inclination of the blade induces a sufficiently accurate knowledge of the angle of bending, of its difference with respect to the desired angle and, lastly, of the correction to make to the bending programme.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Bending Of Plates, Rods, And Pipes (AREA)
EP95200994A 1994-04-22 1995-04-19 Device for measuring a bending angle in a programmable sheet bending brake Ceased EP0679456A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
ITMI940780A IT1269571B (it) 1994-04-22 1994-04-22 Dispositivo per la misura di un angolo di piegatura di un lembo di un foglio di lamiera poligonale e per la correzione automatica di errori di piegatura, particolarmente per una macchina per la piegatura programmabile su tutti i lati del foglio
ITMI940780 1994-04-22

Publications (1)

Publication Number Publication Date
EP0679456A1 true EP0679456A1 (en) 1995-11-02

Family

ID=11368705

Family Applications (1)

Application Number Title Priority Date Filing Date
EP95200994A Ceased EP0679456A1 (en) 1994-04-22 1995-04-19 Device for measuring a bending angle in a programmable sheet bending brake

Country Status (2)

Country Link
EP (1) EP0679456A1 (it)
IT (1) IT1269571B (it)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1057548A2 (en) * 1999-05-14 2000-12-06 SALVAGNINI ITALIA S.p.A. Double function bending blade for sheet metal bending machine
WO2004108318A1 (en) * 2003-06-04 2004-12-16 Finn-Power Oy System for metering the bending angle in a machine for bending metallic sheets and/or sections, as well as method and machine for bending metallic sheets and/or sections using such system
WO2006043292A1 (en) * 2004-10-22 2006-04-27 Finn-Power Oy Kinematic system for the displacement of working units of machines for bending and forming metallic sheets
EP1777017A1 (fr) * 2005-10-21 2007-04-25 Arcelor Steel Service Centres Dispositif de pliage à bras de pliage positif et négatif indépendants
WO2015188208A1 (de) 2014-06-10 2015-12-17 Trumpf Maschinen Austria Gmbh & Co. Kg. Biegepresse mit biegeeinheit sowie verfahren zur umformung

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113523055A (zh) * 2021-06-25 2021-10-22 镇江市丹徒区粮机厂有限公司 一种风机外壳的边缘处翻边装置

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0023894A1 (en) * 1979-08-02 1981-02-11 SALVAGNINI TRANSFERICA S.p.A. Forming press for making perimetral bends on metal sheets
DE3441113A1 (de) * 1984-11-10 1986-05-15 Klöckner-Moeller Elektrizitäts GmbH, 5300 Bonn Biegemaschine mit nummerischer steuerung
DE3643190C1 (en) * 1986-12-18 1988-06-09 Fastenrath Fasti Werk Folding machine
JPH05261444A (ja) * 1991-08-28 1993-10-12 Matsushita Electric Works Ltd 曲げ加工方法
JPH06163317A (ja) * 1992-11-18 1994-06-10 Nichicon Corp 金属化フィルムコンデンサ

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0023894A1 (en) * 1979-08-02 1981-02-11 SALVAGNINI TRANSFERICA S.p.A. Forming press for making perimetral bends on metal sheets
DE3441113A1 (de) * 1984-11-10 1986-05-15 Klöckner-Moeller Elektrizitäts GmbH, 5300 Bonn Biegemaschine mit nummerischer steuerung
DE3643190C1 (en) * 1986-12-18 1988-06-09 Fastenrath Fasti Werk Folding machine
JPH05261444A (ja) * 1991-08-28 1993-10-12 Matsushita Electric Works Ltd 曲げ加工方法
JPH06163317A (ja) * 1992-11-18 1994-06-10 Nichicon Corp 金属化フィルムコンデンサ

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
PATENT ABSTRACTS OF JAPAN vol. 10, no. 227 (M - 505)<2283> 7 August 1986 (1986-08-07) *
PATENT ABSTRACTS OF JAPAN vol. 18, no. 23 (M - 1541) 14 January 1994 (1994-01-14) *

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1057548A2 (en) * 1999-05-14 2000-12-06 SALVAGNINI ITALIA S.p.A. Double function bending blade for sheet metal bending machine
EP1057548A3 (en) * 1999-05-14 2001-05-16 SALVAGNINI ITALIA S.p.A. Double function bending blade for sheet metal bending machine
US6363766B1 (en) 1999-05-14 2002-04-02 Salvagnini Italia S.P.A. Double function bending blade for sheet metal bending machine
WO2004108318A1 (en) * 2003-06-04 2004-12-16 Finn-Power Oy System for metering the bending angle in a machine for bending metallic sheets and/or sections, as well as method and machine for bending metallic sheets and/or sections using such system
WO2006043292A1 (en) * 2004-10-22 2006-04-27 Finn-Power Oy Kinematic system for the displacement of working units of machines for bending and forming metallic sheets
EP1777017A1 (fr) * 2005-10-21 2007-04-25 Arcelor Steel Service Centres Dispositif de pliage à bras de pliage positif et négatif indépendants
WO2007045770A1 (fr) * 2005-10-21 2007-04-26 Arcelor Steel Service Centres Dispositif de pliage a bras de pliage positif et negatif independants
WO2015188208A1 (de) 2014-06-10 2015-12-17 Trumpf Maschinen Austria Gmbh & Co. Kg. Biegepresse mit biegeeinheit sowie verfahren zur umformung
CN106660095A (zh) * 2014-06-10 2017-05-10 特鲁普机械奥地利有限公司及两合公司 具有弯曲单元的压弯机以及用于成形的方法
CN106660095B (zh) * 2014-06-10 2019-04-23 特鲁普机械奥地利有限公司及两合公司 具有弯曲单元的压弯机以及用于成形的方法
US10464115B2 (en) 2014-06-10 2019-11-05 Trumpf Maschinen Austria Gmbh & Co. Kg. Bending press having bending unit, and reshaping method

Also Published As

Publication number Publication date
IT1269571B (it) 1997-04-08
ITMI940780A0 (it) 1994-04-22
ITMI940780A1 (it) 1995-10-22

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