EP0555528A1 - A pipe straightening machine - Google Patents

A pipe straightening machine Download PDF

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Publication number
EP0555528A1
EP0555528A1 EP92118388A EP92118388A EP0555528A1 EP 0555528 A1 EP0555528 A1 EP 0555528A1 EP 92118388 A EP92118388 A EP 92118388A EP 92118388 A EP92118388 A EP 92118388A EP 0555528 A1 EP0555528 A1 EP 0555528A1
Authority
EP
European Patent Office
Prior art keywords
pipe
machine
distance
axes
machine according
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Withdrawn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
EP92118388A
Other languages
German (de)
English (en)
French (fr)
Inventor
Giorgio Quecchia
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.)
SMS Group SpA
Original Assignee
Innse Innocenti Engineering 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 Innse Innocenti Engineering SpA filed Critical Innse Innocenti Engineering SpA
Publication of EP0555528A1 publication Critical patent/EP0555528A1/en
Withdrawn legal-status Critical Current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
    • B21D3/00—Straightening or restoring form of metal rods, metal tubes, metal profiles, or specific articles made therefrom, whether or not in combination with sheet metal parts
    • B21D3/02—Straightening or restoring form of metal rods, metal tubes, metal profiles, or specific articles made therefrom, whether or not in combination with sheet metal parts by rollers
    • B21D3/04—Straightening or restoring form of metal rods, metal tubes, metal profiles, or specific articles made therefrom, whether or not in combination with sheet metal parts by rollers arranged on axes skew to the path of the work

Definitions

  • This invention relates to a pipe straightening machine of a type which includes at least one lower roll and an upper roll, both journalled on respective supports and spaced one from the other to a set distance between their axes.
  • Pipe straightening machines apply substantially corrective deformations to pipes passed longitudinally therethrough, modifying shape imperfections like bends in their middle body or distortions originated by torsional stresses along the pipe axis.
  • straightener will be used hereinafter as an abbreviation to indicate a pipe straightening machine of the kind outlined above.
  • a pipe straightener basically comprises a set of rolls arranged to lie in an upper plane and a set of rolls lying in a lower plane, with the rolls being disposed in juxtaposed pairs; said juxtaposed rolls have mutually skewed axes whose inclination angle in the respective planes can be adjusted using conventional means.
  • the rolls are journalled on a frame structure constituting the load-bearing portion of the machine; all the rolls are provided with drives for their rotary movement which causes a pipe, to move forward along the longitudinal axis of the machine.
  • Such machines are equipped with conventional mechanical means for setting the position of each roll along a perpendicular direction to the longitudinal machine axis.
  • This setting practically enables the distance which separates the axes of the juxtaposed upper and lower rolls, to be changed and it is performed by a workman before each pipe is processed.
  • the distances between the axes of the various rolls are set in order to achieve an ultimate deformation to be applied to the pipe; these distances are set according to previously computed theoretical values of the deformations that the pipe is to undergo in passing through the straightener.
  • the mechanical means for setting the roll distance between axes do not allow the adjustment of this distance as a pipe is being processed.
  • the underlying technical problem of this invention is to provide a pipe straightener with such construction and performance features as to overcome the aforementioned drawbacks with which the prior art is beset.
  • a pipe straightener as indicated being characterized in that it is provided, at the location of at least one of the rolls, with a hydraulic cylinder-piston unit acting on respective supports thereof to change said distance between the axes.
  • a pipe straightener according to the invention; this machine includes a plurality of rolls 2 which are respectively grouped into a set of lower rolls 2a and a set of upper rolls 2b, advantageously opposed one to the other.
  • the upper and lower rolls are respectively laid side-by-side along a longitudinal axis L of the machine 1, which axis would coincide with the axis of a pipe being processed.
  • each upper roll 2b and corresponding lower roll 2a coincide with respective skewed axes A of rotation set at a predetermined controllable distance D one to the other for each pair of juxtaposed rolls, as explained hereinafter.
  • the machine 1 comprises a plurality of pairs of pillars 3 extending symmetrically about the axis L from a load-bearing structure 4 provided for supporting the machine as a whole.
  • the upper rolls 2b are mounted on a pair of supports 5 for supporting their bearings, which are rigidly connected to a hydraulic cylinder-piston unit 6 for adjusting the distance between the axes; the unit 6 is attached to top ends 3a of a pillar pair.
  • the lower rolls are journalled on the load-bearing structure 4 between bottom ends 3b of the pillars 3.
  • Each roll 2 of the machine is connected to respective rotary drives 7 and 8 through a drive adapter 9; particularly in a preferred embodiment, the drive adapters 9 for the lower rolls 2a are connected to the drives 7, and the drive adapters 9 for the upper rolls 2b are connected to the drives 8.
  • This unit comprises a stationary part 10 attached rigidly to the pillars 3 and a moving part 11.
  • the moving part 11 is slidable, relative by to the stationary part 10, parallel to the distance D between axes working as a piston movable inside the cylinder-piston unit 6.
  • the moving part 11 comprises a circular base plate 12 whence there extend three concentrical cylinder walls, respectively inner 13, intermediate 14 and outer 15 walls.
  • the intermediate cylinder wall 14 has a flange 16 which extends radially toward the inner wall 13 to meet a cylindrical lug 10a on the stationary part 10 of the device; the walls 13 and 14, flange 16, and plate 12 delimit a cylindrical chamber C.
  • first and second conduits 17 and 18 are provided in the lug 10a for feeding pressurized oil into the cylindrical chamber C at corresponding sockets 17a and 18a respectively formed in the flange 16 and the plate 12 on their cylindrical chamber C side.
  • the cylinder-piston unit 6 for adjusting the distance between axes also comprises a servo-control 19 having a pressurized oil pumping assembly 20 connected to said first and second conduits 17 and 18, a pressure transducer 21, a pressure relief valve 22, a valve 23, a positional transducer 24, and an adjustment block 25.
  • the positional transducer 24 locates inside the cylindrical lug 10a, and the pressure transducer 21 gauges the pressure of oil being pumped through the conduits 17 and 18.
  • FIG. 3 Shown in Figure 3 in block diagram form is the servo-control 19, which comprises first and second loops A1 and A2 for so-called force and position setting of the cylinder-piston unit 6, respectively.
  • the pipe straightener of this invention also includes means 26, e.g. photocells in this embodiment, for surveying the position of a pipe within the machine, and electronic means 27 of controlling and monitoring the operations of the machine and its parts.
  • the electronic means 27 are entered a reference value of the force to be exerted on the pipe workpiece by each upper roll 2b.
  • the force setting loop A1 is activated by the electronic means 27 in the servo-control 19 of each upper roll 2b.
  • the pipe to be processed is driven along the longitudinal axis L of the machine by rotating the rolls 2 through the drives 7 and 8.
  • the force exerted by the rolls 2 on the pipe is adjusted in real time and maintained at the entered value by means of the servo-control 19.
  • the upward or downward displacement of the moving part 11 results, therefore, in a change in the pressure of the oil within the cylindrical chamber C, which change will be sensed by the transducer 21.
  • the servo-control 19 arranged to act in the force loop A1 mode will control the valve 23 via the adjustment block 25 to vary the delivery of oil through either conduit 17 or 18, depending on whether the moving part 11 is to be raised or lowered, while maintaining constant the force exerted by the upper roll 2b, rigid therewith, on the pipe.
  • the surveying means 26 locate the end positions along the machine and supply the information to the electronic means; the latter then control the upper rolls 2b affected by the passage of said ends to move and be promptly set by the respective cylinder-piston units to a distance between axes A equal to that stored in the electronic means.
  • the pipe straightener according to the present invention may be also operated in the position setting loop A2 mode; in this case, the servo-control 19 would keep the distance between the roll axes A in each pair equal to that entered on the electronic means 27 which corresponds to the nominal diameter of the pipe workpiece.
  • the position setting loop A2 is activated by said electronic means 27.
  • the dimensional variations of the pipe tend to induce displacement of the upper roll 2b, and hence of the moving part 11 of the servo-control attached thereto; the position transducer 25 senses such displacement and reports it to the adjustment block 25, which will control the valve 23 to adjust the oil flow through either conduit 17 or 18 so as to keep the upper roll in its set position.
  • the upset ends can be processed substantially in the same way as previously described in connection with operation in the force setting loop A1 mode.
  • the electronic means 27 should control those rolls which are not affected by the pipe being processed, to keep operating in the force setting loop A1 mode according to program.
  • the surveying means 26 locate the positions of the upset ends through the machine and report them to the electronic means 27; those rolls which are progressively contacted by the ends while operating in the setting loop A1 mode, will position themselves at the set distance corresponding thereto in quite the same way as previously described.
  • the electronic means will switch the operation of the respective servo-control 19 from loop A1 to the position setting loop A2.
  • a pipe straightener according to the invention affords high flexibility of operation, since it allows processing of the pipes throughout their total length; in addition, it is indifferent whether the pipes have lenghtwise sections with uneven outside diameters or upset ends.
  • the pressure relief valve 22 provided will ensure safe operation of the machine as a whole: in fact, where a pipe is started therethrough by mistake whose dimensions are much greater than the set dimensions according to the machine program, there would occur an abnormal rise in the servo-control oil pressure likely to result in failure of the same and a damaged machine.
  • this pipe straightener as described above may be improved or modified to improve its performance, e.g. by using special working programs to be stored in the electronic control means.
  • the machine according to this invention can be modified, in order to meet different requirements such as economical or throughput demands, by equipping it with hydraulic cylinder-piston units not only at the upper rolls but also at the lower ones or, alternatively, just at some of the upper and/or lower rolls, in a broad range of possible combinations.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
EP92118388A 1992-02-12 1992-10-28 A pipe straightening machine Withdrawn EP0555528A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
ITMI920289 1992-02-12
ITMI920289A IT1254783B (it) 1992-02-12 1992-02-12 Macchina per il raddrizzamento di tubi

Publications (1)

Publication Number Publication Date
EP0555528A1 true EP0555528A1 (en) 1993-08-18

Family

ID=11361921

Family Applications (1)

Application Number Title Priority Date Filing Date
EP92118388A Withdrawn EP0555528A1 (en) 1992-02-12 1992-10-28 A pipe straightening machine

Country Status (2)

Country Link
EP (1) EP0555528A1 (it)
IT (1) IT1254783B (it)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1998032552A1 (en) * 1997-01-23 1998-07-30 Demag Italimpianti S.P.A. A machine for straightening tubes and rod-shaped bodies in general
DE19724300A1 (de) * 1997-06-09 1998-12-10 Wrt Metallbearbeitungsmaschine Rohr- oder Stangenrichtvorrichtung
CN101791640A (zh) * 2010-03-22 2010-08-04 中信重工机械股份有限公司 一种大型多斜辊矫直机平衡、锁紧缸的分配方法

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1106054A (en) * 1964-03-24 1968-03-13 Dalmine Spa Apparatus for straightening by rolling bars or tubes of circular cross section whose diameters vary along their length
DE1752511A1 (de) * 1967-06-09 1971-06-03 Redman Tools Holding Ltd Richtmaschine fuer Rohre oder Stangen
US3911708A (en) * 1973-06-08 1975-10-14 Kieserling & Albrecht Apparatus for straightening long metal workpieces
GB1478151A (en) * 1973-10-03 1977-06-29 Kieserling Albrecht T Method and apparatus for straightening lengths of material particularly rods and tubes
US4471639A (en) * 1982-11-01 1984-09-18 E. W. Bliss Company, Inc. Roll orientation control system for straightening machines

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1106054A (en) * 1964-03-24 1968-03-13 Dalmine Spa Apparatus for straightening by rolling bars or tubes of circular cross section whose diameters vary along their length
DE1752511A1 (de) * 1967-06-09 1971-06-03 Redman Tools Holding Ltd Richtmaschine fuer Rohre oder Stangen
US3911708A (en) * 1973-06-08 1975-10-14 Kieserling & Albrecht Apparatus for straightening long metal workpieces
GB1478151A (en) * 1973-10-03 1977-06-29 Kieserling Albrecht T Method and apparatus for straightening lengths of material particularly rods and tubes
US4471639A (en) * 1982-11-01 1984-09-18 E. W. Bliss Company, Inc. Roll orientation control system for straightening machines

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1998032552A1 (en) * 1997-01-23 1998-07-30 Demag Italimpianti S.P.A. A machine for straightening tubes and rod-shaped bodies in general
DE19724300A1 (de) * 1997-06-09 1998-12-10 Wrt Metallbearbeitungsmaschine Rohr- oder Stangenrichtvorrichtung
CN101791640A (zh) * 2010-03-22 2010-08-04 中信重工机械股份有限公司 一种大型多斜辊矫直机平衡、锁紧缸的分配方法
CN101791640B (zh) * 2010-03-22 2012-05-30 中信重工机械股份有限公司 一种大型多斜辊矫直机平衡、锁紧缸的分配方法

Also Published As

Publication number Publication date
ITMI920289A0 (it) 1992-02-12
IT1254783B (it) 1995-10-11
ITMI920289A1 (it) 1993-08-12

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