EP0025469A1 - Verfahren und hydraulische Einrichtung zum Verstellen der Eindringtiefe des Stempels einer hydraulischen Abkantpresse - Google Patents

Verfahren und hydraulische Einrichtung zum Verstellen der Eindringtiefe des Stempels einer hydraulischen Abkantpresse Download PDF

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Publication number
EP0025469A1
EP0025469A1 EP79810097A EP79810097A EP0025469A1 EP 0025469 A1 EP0025469 A1 EP 0025469A1 EP 79810097 A EP79810097 A EP 79810097A EP 79810097 A EP79810097 A EP 79810097A EP 0025469 A1 EP0025469 A1 EP 0025469A1
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EP
European Patent Office
Prior art keywords
cylinders
opposite
thrust
chambers
pressure
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Withdrawn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
EP79810097A
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English (en)
French (fr)
Inventor
Arthur Huber
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.)
Beyeler Machines SA
Original Assignee
Beyeler Machines SA
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 Beyeler Machines SA filed Critical Beyeler Machines SA
Priority to EP79810097A priority Critical patent/EP0025469A1/de
Publication of EP0025469A1 publication Critical patent/EP0025469A1/de
Withdrawn legal-status Critical Current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
    • B21D5/00—Bending sheet metal along straight lines, e.g. to form simple curves
    • B21D5/02—Bending sheet metal along straight lines, e.g. to form simple curves on press brakes without making use of clamping means
    • B21D5/0272—Deflection compensating means
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B30—PRESSES
    • B30B—PRESSES IN GENERAL
    • B30B15/00—Details of, or accessories for, presses; Auxiliary measures in connection with pressing
    • B30B15/16—Control arrangements for fluid-driven presses
    • B30B15/18—Control arrangements for fluid-driven presses controlling the reciprocating motion of the ram

Definitions

  • the present invention relates to a method for correcting the penetration depth of the punch of a hydraulic press brake comprising means for limiting stroke as well as at least one double-acting hydraulic cylinder or pair of opposite single-acting hydraulic cylinders. . It also relates to a hydraulic circuit installation for the execution of the process.
  • Swiss patent 411755 to Willy BEYELER describes a hydraulic press in which the deflection of the slider and the wear of the tool are compensated by means of two stops serving as rigid support at the ends of the slider while the middle part thereof continues its course under the effect of median cylinders, thereby undergoing a bending of its median portion. Variations in angle observed during folding can thus be corrected during this same single folding operation, without returning the slide to the rest position. The folding angle obtained will be the same over the entire length of the workpiece.
  • the machined sheet reacts . to a certain extent elastically at the pressure of the punch, so that its folding angle reopens somewhat when the pressure ceases; this reaction too can be seen during machining, but can hardly be calculated in advance.
  • the forces acting on the stops are such, during the folding operation, that it is generally excluded to then move the stops.
  • the precise adjustment of the penetration depth of the punch is generally carried out in two or more stages, the position of the stops being modified between each folding operation until the desired folding angle is obtained.
  • press brakes comprising hydraulic means for limiting the stroke of the jacks
  • movement of the stops remains possible during the folding operation, as long as the latter only uses small and medium pressures; it then suffices to partially reduce the pressure in the chambers containing the stroke limitation means, in order to increase the extensior maximum that the cylinders can reach.
  • the fluids used for the stroke limitation are to some extent compressible, so that the adjustment of the penetration depth of the punch is less precise than for mechanical stops.
  • the present invention aims to allow the correction, during the folding operation, of the dead center of maximum penetration of the punch for press brakes having means of limitation of stroke.
  • the correction method is characterized in that a thrust is maintained on the part of at least one cylinder, that a pressure is created in the opposite chamber of at least one cylinder which causes a opposite thrust of the starts from at least one double-acting cylinder, or pair of single-acting cylinders, and compensates for all or part of the forces opposed thereto, and then the stroke limitation means are displaced by suitable means which are known per se , despite persistent pressure of the punch on the sheet metal to be machined.
  • the method can be applied equally to press brakes comprising mechanical stroke limitation means and to those comprising hydraulic stroke limitation means.
  • the advantages of the process according to the invention are in particular the following:
  • the limited opposite thrust is sufficient to allow the fold of the sheet to reopen; the operator can therefore observe a possible difference in angle with respect to that desired.
  • This opposite thrust is also sufficient to unload the stops and allow them to be adjusted without returning the slide to the rest position, that is to say without wasting time.
  • As for the maintenance of a thrust on the part of certain jacks it prevents an untimely movement of the sheet during the correction of the penetration depth of the punch, regardless of the weight of the slide and the trigger force respectively (elasticity and thickness , weight acting as a lever) of the sheet.
  • the installation of a hydraulic circuit enabling the process to be carried out is characterized in that the pressure P contained in the chambers of cylinder of double-acting cylinders can be reduced in favor of a back pressure P 'in chambers opposite of such cylinders.
  • FIGS 3 and 4 show a press brake conforming to that shown in the description of the aforementioned Swiss patent 411755.
  • This press comprises two lateral cylinders 1 with single effect and two median cylinders 2 with double effect; the diameter of the cylinders (D) and the pistons (d) is assumed to be the same in the four cylinders.
  • a socket actuated by an endless screw is housed in each of the cylinders of the two lateral jacks and forms a mechanical stop there.
  • the opposite thrust exerted by the two lateral jacks is thus balanced by a thrust opposite of the central cylinders, so that the stops only have to support the weight of the slide 4.
  • the opposite thrust exerted by the middle cylinders 2 is increased relative to the thrust P of veri side 1, in order to decrease, or even completely remove the weight of the slide 4 and thus further facilitate the movement of the stops.
  • a further increase in the back pressure P ′ would cause the punch 6 to be raised, which would then detach from the sheet 5 and the fixed apron 7 situated below; such an increase in the back pressure P ′ is possible, but does not contribute to facilitating the movement of the stops 3 and on the contrary has the drawback that the sheet 5 risks tilting, or even falling from the matrix 8 during lifting of the punch 6, unless the sheet is fixed, for example to punch 6.
  • the actual movement of the stops it is carried out in this case by means of the endless screws (cf. in particular fig. 4) above .
  • the method according to the invention can be used, with the installation of an adequate circuit, in all hydraulic press brakes which include a mechanical stop and at least one double-acting cylinder or torque opposed to single acting.
  • all hydraulic press brakes which include a mechanical stop and at least one double-acting cylinder or torque opposed to single acting.
  • the surface area of the pistons is not the same from one cylinder to another, the pressure required in the double-acting cylinder chambers will be different from that remaining in the single-acting cylinders; for technical reasons different from the problem dealt with here, the rods of the pistons of double-acting cylinders are often of different diameter than those of single-acting cylinders.
  • each of the cylinders will also be different from the opposite thrust required of each of the double-acting cylinders when their respective number does not correspond.
  • the median cylinder 2 in an embodiment comprising two lateral cylinders 1 with single effect and a single median cylinder with double effect, the median cylinder 2 must exert the double thrust of a cylinder with single effect 1, in order to compensate for the presson P, and it must exert a greater thrust to also compensate for the weight of the slide 4.
  • press brakes comprising at least three double-acting central cylinders 2
  • the opposite thrust P 'of the middle cylinders 2 can be proportionally less to compensate for the pressure of the cylinders single acting; the distribution of the hydraulic fluid between the chambers of the different cylinders 2 is modified accordingly.
  • the press brake comprises a total of five cylinders whose cylinder chambers and pistons are assumed to be all of the same diameter; only two of the cylinders of the middle cylinders 2 there receive a back pressure P 'equal to the pressure P remaining in the side cylinders 1, while the pressure has simply been reduced in the cylinder of the third double-acting cylinder and that no back pressure is created there .
  • P 'equal to the pressure P remaining in the side cylinders 1 the pressure has simply been reduced in the cylinder of the third double-acting cylinder and that no back pressure is created there .
  • the method applied to press brakes comprising at least three jacks and mechanical stops arranged inside two lateral jacks 1 with single effect.
  • the invention is not limited thereto. It is applicable in particular when the press brake comprises only double-acting cylinders and the stops are arranged inside such cylinders.
  • press brakes the stops of which are arranged outside the jacks (possibly in the axis of the lateral jacks) and thus constitute a stop for the punch itself; in this case also, double-acting cylinders 2 (or opposite single-acting cylinders) have the task of creating an opposite thrust making it possible to partially compensate for the thrust P exerted by jacks remaining under pressure, the weight of the slide and, optionally, that of the machined sheet (in the case where the stop is arranged under the die 8 carrying the sheet 5).
  • the invention can also find an application for press brakes in which the slide 4 is pushed from the bottom against an apron.
  • it is not only the expansion force of the workpiece 5 which opposes the thrust of the jacks, but also the weight of the slide, so that the displacement of the stops can be carried out by means of a somewhat reduced reverse thrust P ′ on the part of the middle jacks 2, compared with those necessary in the abovementioned embodiments.
  • the invention also finds application in press brakes which do not have systems for compensating for the deflections of the slide 4 and the deck 7.
  • the method can also be applied to press brakes comprising hydraulic means (stops) of stroke limitation.
  • the opposite thrust exerted by double-acting cylinders 2 (or opposite single-acting cylinders) compensates for the thrust of the cylinders pressing against the hydraulic stop 3, which allows easy adjustment of the hydraulic stroke limitation means and therefore precise movement of the neutral point for maximum cylinder extension.
  • a press brake comprising five jacks, as shown diagrammatically in FIGS. 5 and 6, is equipped with an installation comprising a single pump (not shown), capable of distributing the hydraulic fluid, in during work, between the different cylinder chambers and divert the excess fluid from the middle cylinder chamber to an expansion tank until the stops are set differently.
  • the distribution of the fluid can be carried out by means of valves (not shown) of constant value distribution (Konstantstromteiler).
  • hydraulic fluid is derived from the thrust chambers to the opposite chambers of the two cylinders of the middle cylinders 2 to create the back pressure P '.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Bending Of Plates, Rods, And Pipes (AREA)
EP79810097A 1979-09-17 1979-09-17 Verfahren und hydraulische Einrichtung zum Verstellen der Eindringtiefe des Stempels einer hydraulischen Abkantpresse Withdrawn EP0025469A1 (de)

Priority Applications (1)

Application Number Priority Date Filing Date Title
EP79810097A EP0025469A1 (de) 1979-09-17 1979-09-17 Verfahren und hydraulische Einrichtung zum Verstellen der Eindringtiefe des Stempels einer hydraulischen Abkantpresse

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
EP79810097A EP0025469A1 (de) 1979-09-17 1979-09-17 Verfahren und hydraulische Einrichtung zum Verstellen der Eindringtiefe des Stempels einer hydraulischen Abkantpresse

Publications (1)

Publication Number Publication Date
EP0025469A1 true EP0025469A1 (de) 1981-03-25

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Family Applications (1)

Application Number Title Priority Date Filing Date
EP79810097A Withdrawn EP0025469A1 (de) 1979-09-17 1979-09-17 Verfahren und hydraulische Einrichtung zum Verstellen der Eindringtiefe des Stempels einer hydraulischen Abkantpresse

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EP (1) EP0025469A1 (de)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0155228A1 (de) * 1984-02-03 1985-09-18 Beyeler Machines S.A. Plattenbiegemaschine, deren Biegemechanismus eine Überwachung des Biegewinkels gestattet
CN106391776A (zh) * 2015-09-17 2017-02-15 佛山高富中石油燃料沥青有限责任公司 一种改进的可调节的金属板材弯折装置
CN108655225A (zh) * 2018-04-26 2018-10-16 中铁武汉电气化局集团科工装备有限公司 钢管硬横梁主弦杆自动折弯机及其控制方法
CN113770213A (zh) * 2021-09-02 2021-12-10 中船澄西船舶修造有限公司 一种脚手架卡板批量加工工装

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB667323A (en) * 1950-02-17 1952-02-27 John Pidcock Improvements relating to bending machines
FR1128138A (fr) * 1955-06-27 1957-01-02 Perfectionnements apportés aux vérins hydrauliques et leurs applications, plus spécialement aux presses-plieuses
US3062132A (en) * 1960-03-21 1962-11-06 Cleveland Crane Eng Hydraulic press brake
CH411755A (fr) * 1964-04-24 1966-04-30 Beyeler Willy Presse pour le pliage de tôle
FR1517000A (fr) * 1967-01-31 1968-02-05 Perfectionnements aux vérins hydrauliques en vue, notamment, de leur application àdes presses ou machines analogues
DE1817102A1 (de) * 1968-12-27 1970-07-16 Scharringhausen Maschb Gmbh Vorrichtung zur Hubeinstellung und -begrenzung an einer Abkantpresse
DE1920969A1 (de) * 1969-04-24 1970-11-05 Bussmann Kg Wilhelm Hydraulische Metallpulverpresse
US3874205A (en) * 1974-02-19 1975-04-01 Hurco Mfg Co Inc Digitally controlled multiple depth stop and return stroke limit control for press brakes
DE2832981A1 (de) * 1977-07-30 1979-02-15 Amada Co Ltd Hubeinstelleinrichtung fuer hydraulische schubkolbengetriebe, insbesondere fuer hydraulische pressen oder sonstige maschinen

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB667323A (en) * 1950-02-17 1952-02-27 John Pidcock Improvements relating to bending machines
FR1128138A (fr) * 1955-06-27 1957-01-02 Perfectionnements apportés aux vérins hydrauliques et leurs applications, plus spécialement aux presses-plieuses
US3062132A (en) * 1960-03-21 1962-11-06 Cleveland Crane Eng Hydraulic press brake
CH411755A (fr) * 1964-04-24 1966-04-30 Beyeler Willy Presse pour le pliage de tôle
FR1517000A (fr) * 1967-01-31 1968-02-05 Perfectionnements aux vérins hydrauliques en vue, notamment, de leur application àdes presses ou machines analogues
DE1817102A1 (de) * 1968-12-27 1970-07-16 Scharringhausen Maschb Gmbh Vorrichtung zur Hubeinstellung und -begrenzung an einer Abkantpresse
DE1920969A1 (de) * 1969-04-24 1970-11-05 Bussmann Kg Wilhelm Hydraulische Metallpulverpresse
US3874205A (en) * 1974-02-19 1975-04-01 Hurco Mfg Co Inc Digitally controlled multiple depth stop and return stroke limit control for press brakes
DE2832981A1 (de) * 1977-07-30 1979-02-15 Amada Co Ltd Hubeinstelleinrichtung fuer hydraulische schubkolbengetriebe, insbesondere fuer hydraulische pressen oder sonstige maschinen

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0155228A1 (de) * 1984-02-03 1985-09-18 Beyeler Machines S.A. Plattenbiegemaschine, deren Biegemechanismus eine Überwachung des Biegewinkels gestattet
CN106391776A (zh) * 2015-09-17 2017-02-15 佛山高富中石油燃料沥青有限责任公司 一种改进的可调节的金属板材弯折装置
CN108655225A (zh) * 2018-04-26 2018-10-16 中铁武汉电气化局集团科工装备有限公司 钢管硬横梁主弦杆自动折弯机及其控制方法
CN113770213A (zh) * 2021-09-02 2021-12-10 中船澄西船舶修造有限公司 一种脚手架卡板批量加工工装

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Inventor name: HUBER ARTHUR