US3835682A - Hydraulic presses - Google Patents

Hydraulic presses Download PDF

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Publication number
US3835682A
US3835682A US00291087A US29108772A US3835682A US 3835682 A US3835682 A US 3835682A US 00291087 A US00291087 A US 00291087A US 29108772 A US29108772 A US 29108772A US 3835682 A US3835682 A US 3835682A
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US
United States
Prior art keywords
cylinder
pressure
workpiece
length
ram assembly
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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.)
Expired - Lifetime
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US00291087A
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English (en)
Inventor
R Elger
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.)
Mannesmann Meer AG
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Mannesmann Meer AG
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Publication date
Application filed by Mannesmann Meer AG filed Critical Mannesmann Meer AG
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    • 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
    • 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
    • B21D5/01—Bending sheet metal along straight lines, e.g. to form simple curves between rams and anvils or abutments

Definitions

  • Cl 72/14, 72/20, 72/404 form The pressure of one cylinder/ram assembly j 72/553 cent one end of the workpiece is controlled in depen- [51] Int. Cl B2lj 9/20 dehee p the ratio of the length of the end portion [58] Field of Sear h 72/453, 404, 405, 14 20 of that workpiece over the length of the zone covered by that one cylinder/ram assembly. [56] References Cited UNITED STATES PATENTS 8 Claims, 4 Drawing Figures 999,661 8/1911 Kunkle .1 72/453 1.1?
  • This invention relates to hydraulic presses and has particular, although not exclusive, reference to pipeforming presses.
  • a workpiece in the form of a fiat plate is deformed into a U-shape by a first press and is then transferred to a second and separate press where the U-shaped plate is further deformed into an O-shape.
  • Known O-form press designs are of the laminated frame type in which a row of cylinder assemblies are mounted within individual sub-frames comprising the press structure.
  • the cylinder assemblies are adapted to provide movement of an upper tool assembly relative to a lower stationary tool assembly which is mounted below the upper assembly and passes axially through the sub-frames.
  • the lower tool assembly is adapted, in use, to receive the U-shaped plate from equipment outside the press, whereupon the press cylinder assemblies are actuated to advance the upper tool assembly to further deform the U-shaped plate into an O-shape.
  • the upper tool assembly is then withdrawn and the section tube is conveyed out of the press for subsequent welding, testing, etc.
  • Pipes made in this way can vary in length up to a maximum determined by the length of the press tool assemblies.
  • the ends of the tools and tool supports will overhang the ends of the workpiece and consequently will not be reacted on by the workpiece during the deforming operation. This can create a potentially excessive bending moment in the tool support structure, and in known presses this has been overcome by unloading those cylinders which act beyond the plate extremities.
  • a method controlling a hydraulic press having a row of hydraulic cylinder/ram assemblies for applying pressure to a workpiece of generally elongate form includes the step of controlling the pressure exerted by one, or two or more adjacent cylinder/ram assemblies, under which a portion of one end of the workpiece extends, in dependence upon the ratio of the length of the said end portion of the workpiece which extends into a zone over which the force exerted by the said one, or two or more cylinder is effective, to the length of the zone measured in a direction along the longitudinal axis of the press.
  • the method includes the further step of ensuring that the ratio of the pressure exerted by the said one, or two or more adjacent cylinder/ram assemblies to the pressure exerted by any other cylinder/ram assembly under which the workpiece extends fully. is equal to the aforesaid length ratio.
  • a first signal representative of the pressure exerted by the said any other cylinder/arm assembly and a second signal representative of said length ratio can be fed to comparator means the output from which is used to control the pressure exerted by the said one or two or more cylinder/ram assemblies.
  • the second signal can be produced by sensing means used to detect a reference point on the workpiece such as the leading or trailing edge thereof.
  • the pressure exerted by one, or two or more adjacent cylinder/ram assemblies under which a portion of the other end of the workpiece extends may also be controlled in dependence upon a similar length ratio.
  • Apparatus for carrying out the aforesaid method may include a row of hydraulic cylinder/ram assemblies for applying pressure to the workpiece, and means for enabling the pressure of one or, two or more adajcent cylinder/ram assemblies associated with one or each end of the workpiece to be controlled in the aforesaid length ratio.
  • the said means can comprise sensing means for providing a first signal representative of said length ratio, means for providing a signal representative of the pressure in said any other cylinder/ram as sembly and comparator means for receiving said signals and producing an output for controlling the pressure in said one or two or more cylinder/ram assemblies.
  • the sensing means can be adapted to detect a reference point on the workpiece such as the leading or trailing edge thereof.
  • FIG. 1 is a sectional elevation of the press along line II of FIG. 2;
  • FIG. 2 is a part section along line II-II of FIG. 1;
  • FIG. 3 is a part section along line IIIIII of FIG. 1;
  • FIG. 4 is a diagrammatic representation of a control system for the press shown in FIGS. 1 to 3.
  • the press frame 1 shown in FIGS. 1 to 3 incorporates a series of subframes comprised of plates 2 held in fixed spacial relationship by bolts 3 and diaphragms 4.
  • cylinder/ram assemblies each incorporating a moving cylinder block 5 and a fixed ram 6 to which assemblies hydraulic medium is fed through connections 7 and passageways 8.
  • the cylinder blocks are returned by the rams 9 of fixed cylinders 10.
  • the movable upper tools 11 of the press are mounted in the cylinder blocks 5 and the fixed lower tools 12 are mounted in supports 13.
  • cylinders A, B, C and D are connected to a source of hydraulic power schematically indicated as pump 14 and a related control means including a by-pass valve 15 and a pressure relief valve 16.
  • Control valves 17A, 17B, 17C, 17D are provided to isolate their respective from the hydraulic power sup ply.
  • Cylinder E is connected to a separate source of hydraulic power indicated as pump 18 and a related control means including a by-pass valve 19, a pressure relief valve 20 and control valve 22.
  • the space between the upper and lower tool sets has been divided into zones A to E these zones represent the area of the tool set over which the force from each respective cylinder may be said to be operative.
  • the zone A represents the area of the tool set over which the force from cylinder A may be said to be operative.
  • Sensing means 23a to 23d are provided to detect the trailing edge of the plate and sensing means 24 are provided to detect the position of the leading edge of the plate.
  • These means may be of any known form, i.e., electrical, mechanical or hydraulic and may be limit switches, photo cells, digitisers, etc.
  • the signal from sensing means 24 which represents the position of the leading edge of the plate in relation to the right-hand end (as seen in FIG. 4) of zone E is transmitted to a comparator means 25.
  • a signal representing the pressure in cylinders A, B, C and D, i.e., the line pressure from pump 14, is also fed into the comparator means 25.
  • the outgoing signal from the comparator means 25 is the product of the value of pressure in cylinders A, B, C and D multiplied by the ratio of the plate length in zone E to the axial length of zone E and is transmitted to the control means of pressure regulating valve 21, thus controlling, as explained in more detail below, the pressure in cylinder E in the desired ratio to the pressure in cylinders A, B, C and D.
  • a pressure feed back signal 26 is taken from the pressure line to cylinder E and transmitted to the comparator means 25 where the signal representing the actual pressure obtained may be compared with the aforesaid control signal to pressure regulating valve 21. If there is a discrepancy in the two values, the control signal is adjusted accordingly whereby the desired pressure is obtained.
  • the press operates as follows:
  • Conveying means transport a partially deformed U-shaped plate (not shown) axially, in the direction of arrow 27, into the press between the top and bottom tools until the sensing means 230 detects the trailing edge of the plate.
  • the conveying means is then stopped and the plate lowered on to the bottom tool with its trailing edge coterminus with the righthand extremity (as seen in FIG. 4) of zone Al. Assuming that a portion of the leading end of the plate extends into zone E then the length of that portion is determined by sensing means 24 and an appropriate signal is transmitted to the comparator means 25.
  • a signal proportional to the pressure in line 14 is received by comparator means 25 and a signal representing the desired value of pressure for cylinder E is transmitted in the manner described above thus controlling the pressure to cylinder E from pump 18.
  • the U-shaped plate is thus formed into an O-shape between the press tools with the pressure in the cylinders A, B, C and D determined by the resistance to deformation of the main body of the product and the pressure in cylinder E controlled in relation to the pressure in cylinders A, B, C and D in the ratio of the plate length in zone E to the length of zone E That is, if the plate length in pressure zone E is three-quarters of the length of zone E the pressure in cylinder E is maintained at three-quarters the pressure in cylinders A, B, C and D.
  • the pipe is kept sensibly central between the axial ends of the press and therefore it would be expedient for the hydraulic power, control and sensing means described above for cylinder E to be duplicated for cylinder D, thus providing separate and variable pressure control for cylinders D and E.
  • the sensing means 24 could be used to detect the length of plate extending into either zone D or E.
  • the press described above could also be modified to incorporate power supply and control means providing a proportional reduction of pressure over two or more adjacent cylinders at one end of the press, thus permitting the use of reduced press power over a longer end portion of plate where the pressure in these cylinders in relation to the pressure in the principal cylinders is in the ratio of the length of plate within the combined pressure zones to the length of the pressure zones.
  • trailing edge of the plate is used as a reference point in the press described, this point may be selected anywhere along the length of the plate.
  • comparator means may be of any suitable type, i.e., mechanical, hydraulic or electrical.
  • a method of controlling a hydraulic press having a row of hydraulic cylinder/ram assemblies for applying pressure to a workpiece of generally elongate form including the step of controlling the pressure exerted by at least one adjacent cylinder/ram assembly, under which a portion of one end of the workpiece extends, in dependence upon the ratio of the length of the said end portion of the workpiece which extends into a zone over which the force exerted by the said cylinder is effective, to the length of the zone measured in a direction along the longitudinal axis of the press.
  • said means comprises sensing means for providing a first signal representative of said length ratio, means for providing a second signal representative of the pressure in said any other cylinder/ram assembly and comparator means for receiving said first and second signals and producing an output for controlling the pressure in said one cylinder/ram assembly.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Control Of Presses (AREA)
  • Bending Of Plates, Rods, And Pipes (AREA)
  • Shaping Metal By Deep-Drawing, Or The Like (AREA)
  • Press Drives And Press Lines (AREA)
US00291087A 1971-09-24 1972-09-21 Hydraulic presses Expired - Lifetime US3835682A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB4471371A GB1415835A (en) 1971-09-24 1971-09-24 Hydraulic presses

Publications (1)

Publication Number Publication Date
US3835682A true US3835682A (en) 1974-09-17

Family

ID=10434436

Family Applications (1)

Application Number Title Priority Date Filing Date
US00291087A Expired - Lifetime US3835682A (en) 1971-09-24 1972-09-21 Hydraulic presses

Country Status (7)

Country Link
US (1) US3835682A (de)
JP (1) JPS4872771A (de)
DE (1) DE2247201C3 (de)
FR (1) FR2155322A5 (de)
GB (1) GB1415835A (de)
IT (1) IT967682B (de)
SU (1) SU465775A3 (de)

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4682401A (en) * 1983-05-19 1987-07-28 Amada Company, Limited Multiple processing machine
US5447050A (en) * 1992-09-30 1995-09-05 Pahnke Engineering Gmbh & Co., Kg Forming machine
US5473926A (en) * 1991-10-18 1995-12-12 Institute Of Technology Precision Electrical Discharge Work's Index-feed machining system
US5526668A (en) * 1991-10-18 1996-06-18 Institute Of Technology Precision Electrical Discharge Work's Index-feed machining system
US5678446A (en) * 1991-10-18 1997-10-21 Institute Of Technology Precision Electrical Discharge Work's Index-feed machining system
US6634205B2 (en) * 2000-11-30 2003-10-21 Kawasaki Hydromechanics Corporation Hydraulic control method for hydraulic press
US6715418B2 (en) * 2001-04-03 2004-04-06 Man Roland Druckmaschinen Ag Apparatus for producing a sleeve-like printing form
US20040155016A1 (en) * 2002-12-21 2004-08-12 Man Roland Druckmaschinen Ag Apparatus for producing a sleeve-shaped printing form
CN105751561A (zh) * 2016-05-05 2016-07-13 海安县巨力磁材有限责任公司 液压机

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2714958C2 (de) * 1977-04-02 1983-01-27 G. Siempelkamp Gmbh & Co, 4150 Krefeld Hydraulische Blechbiegepresse
US4445357A (en) * 1980-11-03 1984-05-01 Kaiser Steel Corporation Pipe press
US4945742A (en) * 1987-08-27 1990-08-07 The Minster Machine Company Monitorable and compensatable feedback tool and control system for a press
US4939918A (en) * 1987-08-27 1990-07-10 The Minster Machine Company Monitorable and compensatable feedback tool and control system for a press
DE102010010990C5 (de) * 2010-03-10 2021-01-28 Siempelkamp Maschinen- Und Anlagenbau Gmbh Rohrbiegepresse

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US999661A (en) * 1910-11-21 1911-08-01 Lorenza H Kunkle Automatic tool-forging machine.
US1975249A (en) * 1930-11-20 1934-10-02 Duff Patents Company Inc Press

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US999661A (en) * 1910-11-21 1911-08-01 Lorenza H Kunkle Automatic tool-forging machine.
US1975249A (en) * 1930-11-20 1934-10-02 Duff Patents Company Inc Press

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4682401A (en) * 1983-05-19 1987-07-28 Amada Company, Limited Multiple processing machine
US5473926A (en) * 1991-10-18 1995-12-12 Institute Of Technology Precision Electrical Discharge Work's Index-feed machining system
EP0538724B1 (de) * 1991-10-18 1996-01-10 Institute Of Technology Precision Electrical Discharge Work's Index-Vorschubsystem
US5526668A (en) * 1991-10-18 1996-06-18 Institute Of Technology Precision Electrical Discharge Work's Index-feed machining system
EP0538725B1 (de) * 1991-10-18 1996-08-28 Institute Of Technology Precision Electrical Discharge Work's Index-Vorschubsystem
US5678446A (en) * 1991-10-18 1997-10-21 Institute Of Technology Precision Electrical Discharge Work's Index-feed machining system
US5447050A (en) * 1992-09-30 1995-09-05 Pahnke Engineering Gmbh & Co., Kg Forming machine
US6634205B2 (en) * 2000-11-30 2003-10-21 Kawasaki Hydromechanics Corporation Hydraulic control method for hydraulic press
US6715418B2 (en) * 2001-04-03 2004-04-06 Man Roland Druckmaschinen Ag Apparatus for producing a sleeve-like printing form
US20040155016A1 (en) * 2002-12-21 2004-08-12 Man Roland Druckmaschinen Ag Apparatus for producing a sleeve-shaped printing form
US6899264B2 (en) * 2002-12-21 2005-05-31 Man Roland Druckmaschinen Ag Apparatus for producing a sleeve-shaped printing form
CN105751561A (zh) * 2016-05-05 2016-07-13 海安县巨力磁材有限责任公司 液压机

Also Published As

Publication number Publication date
IT967682B (it) 1974-03-11
GB1415835A (en) 1975-11-26
DE2247201C3 (de) 1979-02-01
JPS4872771A (de) 1973-10-01
DE2247201B2 (de) 1978-06-08
FR2155322A5 (de) 1973-05-18
DE2247201A1 (de) 1973-03-29
SU465775A3 (ru) 1975-03-30

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