EP0268891A1 - Metallrohrbiegemaschine - Google Patents

Metallrohrbiegemaschine Download PDF

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Publication number
EP0268891A1
EP0268891A1 EP87116269A EP87116269A EP0268891A1 EP 0268891 A1 EP0268891 A1 EP 0268891A1 EP 87116269 A EP87116269 A EP 87116269A EP 87116269 A EP87116269 A EP 87116269A EP 0268891 A1 EP0268891 A1 EP 0268891A1
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EP
European Patent Office
Prior art keywords
pipe
bending
saddle member
cradle
depressions
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Withdrawn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
EP87116269A
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English (en)
French (fr)
Inventor
Germano Fiorito
Marco Fiorito
Vilma Tabaton
Marina Fiorito
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.)
Individual
Original Assignee
Individual
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 Individual filed Critical Individual
Publication of EP0268891A1 publication Critical patent/EP0268891A1/de
Withdrawn legal-status Critical Current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
    • B21D7/00—Bending rods, profiles, or tubes
    • B21D7/06—Bending rods, profiles, or tubes in press brakes or between rams and anvils or abutments; Pliers with forming dies
    • B21D7/066—Bending rods, profiles, or tubes in press brakes or between rams and anvils or abutments; Pliers with forming dies combined with oscillating members

Definitions

  • the object of the invention is an apparatus for bending metal pipes, comprising two lower pipe-bearing cradle members with their internal surface being semi-circular in cross section, which are set in an axially aligned spaced apart relation, and are each pivotably mounted around a transversal axis, while an upper pipe-bending saddle member with an internal surface corresponding to an intrados part of a tore, is provided intermediately between the two pipe-bearing cradle members intended for receiving and supporting from below the pipe to be bent, and is designed for causing the bending of the pipe by straddling it and by being forced downward by a vertical press having the said pipe-bending saddle member secured to the movable plate thereof.
  • the pipe-bending saddle member has a simple toric profile, while the two pipe-bearing cradle members have a simple semi-cylindrical profile.
  • the toric surface of the pipe-bending saddle member and the cylindrical surface of the pipe to be bent are caused to contact each other in correspondence of a point or of an extremely small area.
  • the result is that an excessive specific pressure will be generated, which determines the sinking of the pipe-bending saddle member into the pipe to be bent and, as a consequence, a corresponding narrowing of the pipe and a reduction of its diameter which becomes still more noticeable in the sequence of the various beinding steps.
  • the said inconvenience particularly occurs in bends with a rather reduced radius, as well as in connection with pipes of a mean and a great diameter, having then a wall of a very limited thickness in relation to the pipe diameter.
  • the same inconvenience occurs in correspondence of the pipe-bearing cradles when an already partly bent pipe is supported on a cradle member.
  • the contact surface between the bent pipe and the cylindrical pipe-bearing cradle member is limited to a very narrow area, with the result of an excessive specific pressure being generated on starting the bending, and of a consequent narrowing of the pipe.
  • the main object of the invention is to eliminate or at least to sensibly reduce the above disclosed inconvenience, as well as any defect in the bends made by using the known apparatus of the aforementioned type.
  • At least the pipe-bending saddle member and preferably also the pipe-bearing cradle members have each in the central area of their pipe-contacting surface, at least one lateral depression preferably provided in a zone at about 45° of the saddle member or the cradle member cross-section, and which is smoothly connected to the remaining toric surface of the pipe-bending saddle member or to the remaining semi-cylindrical surface of the pipe-bearing cradle member.
  • two opposite lateral depression of the above stated type are provided, which are symmetric with respect to the longitudinal median vertical plane of the pipe-bending saddle member or of the pipe-bending saddle member or of the pipe-bearing cradle member.
  • a slight pressure applied by means of the pipe-bending saddle member on the pipe to be bent on starting the bending thereof produces a yielding and an expanding of said pipe into the lateral depression or depressions in the saddle member and may be also in the pipe-bearing cradle member, so that in correspondence of the zone of the said depression or depressions a contact surface between the pipe and the pipe-bending saddle member and may be also between the pipe and the pipe-bearing cradle member is thus determined, the said surface being of such a width that on subsequently increasing the pressure up to obtain the moment of flexure as required for bending the pipe, any such specific pressure is prevented from being reached, that would cause the narrowing of said pipe.
  • the previously bent section of the pipe is actually subjected to the action of a portion of the pipe-bending saddle member or of the pipe-bearing cradle member having no depressions, so that it is a fully toric or semi-cylindrical portion, whereby the said pipe section will have its originally circular profile restored.
  • the wide contact surface thus obtained by means of the lateral depression or depressions, between a pipe and the pipe-bending saddle member in the central area of the section affected by the bending, facilitates the bending and reduces the risk of wrinkles, laps, and any other undesired distortion being formed in a bend. Therefore, by using the apparatus according to the invention, highly accurate bends can be obtained in the pipes, with a distortion of their diameter (reduction and ovalization) being, for example, contained within a limit of 0,5-1,5%.
  • the apparatus according to the invention is generally used for cold bending, although it may be also used for hot bending. Moreover, the apparatus according to the invention can be used for bending pipes only in one step of in two or more steps, depending on the bending radius, the thickness of the pipe wall, the pipe diameter, the pipe material, and the like.
  • the apparatus according to the invention can be used for bending pipes of any diameter, although it is particularly adapted for bending pipes of a mean and a great diameter, especially pipes for oil and methane pipelines and generally, for liquid and gas ducts, for example pipes of 54 ⁇ and even of 60 ⁇ and more.
  • pipes of a means and a great diameter have a very low thickness/diameter ratio, so that they are particularly exposed to the risk of being narrowed as a result of any excessive specific pressure at the starting of each bending step.
  • the distance between the swing centers of the two pipe-bearing cradle members needs to be a relatively small one, and to be, for example, maintained within a value of about 3.3 times the diameter of the pipe. Consequently, the force needed for reaching the moment of flexure as required for bending is quite important in relation to the pipe diameter, and just as much important therefore is the extent of the surfaces affected by any excessive specific pressure that produces the narrowing of the pipe cross-­sectional opening.
  • the illustrated pipe bending apparatus comprises a vertical press of which the base 1 and the movable plate 2 are shown.
  • a support comprising two spaced apart side members 3 between which two pipe-bearing cradle members 4 are mounted, the upwardly turned surface 104 thereof being substantially of a semi-cylindrical configuration, so that this surface has over almost the whole of its extent a semi-­circular profile.
  • the two pipe-bearing cradle members 4 are axially and horizontally in line with each other, and are made so as to contain the lower half of a pipe T supported thereon.
  • Each pipe-bearing cradle member 4 is mounted in the support 3-3 so as to be swingable around a transverse horizontal axis.
  • each pipe-bearing cradle member 4 has two co-axial side pins 5 by means of which it is pivotably supported in respective upper seats provided in the side members 3 of the support.
  • the axis of pins 5 forming the swing axis of each pipe-bearing cradle member 4 is located below the axis of the semi-circular profile of the said pipe-bearing cradle member 4.
  • the upper longitudinal edges 204 of the pipe-bearing cradle members 4 are rectilinearly extended in the upward direction beyond the horizontal plane passing through the axis of the semi-­circular profile of said cradle members 4.
  • each pipe-bearing cradle member 4 is approximately 1.2 times the diameter of the pipe T.
  • the distance between the swing axes of the two pipe-bearing cradle members 4, i.e., between the pins 5 for the support and the pivoting of said cradle members 4 is approximately 3.3 times the diameter of the pipe.
  • the upward extension of the upper longitudinal edges 204 of each pipe-bearing cradle member 4 beyond the horizontal axial plane of said cradle member 4 is approximately 1/10 of the diameter of the pipe T.
  • the distance of the axis of pins 5 for each pipe-bearing cradle member 4 from the overlying horizontal axial plane of said cradle member 4 corresponds approximately to 1/10 of the diameter of the pipe T.
  • the pipe-bending saddle member 6 Arranged intermediately between the two pipe-bearing cradle members 4 is the pipe-bending saddle member 6 which is secured to the movable plate 2 of the press.
  • the pipe-bending saddle member 6 is connected to the movable plate 2 of the press through an articulated joint or a knuckle having a transverse horizontal axis of articulation.
  • the said articulated joint consists of a plate 7 which is secured to the plate 2 of the press, such as by means of bolts, and has two downwardly extending side ears 8.
  • a articulation member 9 having a concave lower surface that corresponds to a cylindrical surface segment with a transverse horizontal axis.
  • the mating convex upper surface of an articulation member 10 bears against the said concave lower surface of the articulation member 9, and the said member 10 has its lower planar horizontal surface bearing against the upper planar horizontal surface of the pipe-­bending saddle member 6.
  • bores 11 are made which are co-axial to each other and to the centre of curvature of the mating, concave and convex surfaces of the two superposed articulation members 9,10.
  • the pipe-bending saddle member 6 is secured to the side ears 8 by means of two pins 12 having a diameter which is sensibly smaller than the bores 11, so that the said pins are passed with a correspondingly great play through the said bores 11, to be driven in the pipe-bending saddle member 6.
  • the sensible play between the pins 12 and the bores 11 in the ears 8 guarantees that the pressure of the press will be applied on the pipe-­bending saddle member 6 solely through the two mating articulation members 9,10, and not through the pins 12 that mainly perform the task of holding together the assembly formed by the pipe-bending saddle member 6 and the two articulation members 9,10, when this assembly is suspended from the uplifted movable plate 2 of the press.
  • the lower surface 106 of the pipe-bending saddle member 6, which is turned toward the pipe T, is substantially formed by a tore segment intrados part of 180, with a cross-section like that of the pipe T to be bent, and with a radius being slightly shorter than that of the bend to be made in said pipe.
  • the longitudinal edges 206 of the pipe-bending saddle member 6 are rectilinearly extended downwards, tangentially to the cross-section of the tore, for example over a length of about 1/10 of the diameter of the pipe.
  • two lateral depressions 306 are provided in the lower tore intrados part surface 106 of the pipe-­bending saddle member 6, at the central region of said member 6, and are situated on opposite sides of the longitudinal median vertical plane of the pipe-bending saddle member 6, in correspondence of areas at about 45 from the said plane, and are symmetrical with respect to the said plane. More particularly, each one of these depressions 306 has a maximum depth at its central area, i.e., in correspondence of the median transversal plane of the saddle member 6, at about 45 of the cross-section of the said member 6. Such a depth gradually decreases from the central area of the depression in all direction, so that a smooth connection is obtained of the depression 306 to the remaining toric surface 106 of the saddle member 6.
  • each depression 306 in the longitudinal direction of the pipe-bending saddle member 6 preferably corresponds to the arc chord of the impression produced in pipe T by a pipe-bending saddle member 6 having no depressions 306, as a result of the excessive specific pressure at the beginning of the bending.
  • the extent of each depression 306 in the longitudinal direction of the pipe-bending saddle member 6 is of about 0.6 times the diameter of pipe T.
  • the maximum depth of each depression 306 preferably corresponds substantially to the maximum camber of the said impression arc.
  • each pipe-bearing cradle member 4 two lateral depressions 304 are provided, which are situated on opposite sides of the longitudinal median vertical plane of the pipe-­bearing cradle member 4 in correspondence of areas at about 45° from the said plane, and which are symmetrical with respect to the said plane.
  • Each one of these depressions 304 has a maximum depth in its central region, i.e., in correspondence of the median trans­ versal plane of the pipe-bearing cradle member 4, at about 45° of the semi-circular cross-section of said member 4.
  • Such a maximum depth of the depression 304 preferably corresponds to about one quarter of the maximum depth of the depressions 306 in the pipe-­bending saddle member 6, and gradually decreases in all directions, so that a smooth connection is effected of the depression 304 to the remaining semi-cylindrical surface 104 of the cradle member 4.
  • the extent of each depression 304 in the longitudinal direction of the pipe-bearing cradle member 4 may be defined as previously disclosed in connection with the depression 306 in the pipe-bending saddle member 6 and, for example, it may corresponds to about 0.3 times the diameter of pipe T.
  • the pipe T to be bent is fitted between the raised pipe-bending saddle member 6 and the pipe-bearing cradle members 4 and is accomodated in the two cradle members 4.
  • This contact surface is of such a width that when the pressure as applied on the pipe T by means of the pipe-bending saddle member 6 will be subsequently increased up to attain the moment of flexure as required for the bending of said pipe, no excessive specific pressure will occur, which would be apt to cause a sinking of the pipe-bending saddle member 6 into the pipe T, and so a consequent narrowing of said pipe.
  • the pipe T is therefore bent without substantially reducing its diameter and its cross-sectional opening.
  • the two pipe-bearing cradle members 4 are pivoting in opposite directions about the pins 5, as shown by dash lines in figure 1. Since the pins 5 for the pivoting of the pipe-bearing cradle members 4 are situated below the longitudinal axis of pipe T, the pipe-bearing cradle members 4 are drawn near to each other and bring about a strong compressive stress on the axis of pipe T. This limits the tendency to being stretched of the pipe extrados and the consequent reducing of the thickness of the extrados wall of the pipe.
  • the articulation 9,10 interposed between the movable plate 2 of the press and the pipe-bending saddle member 6 permits the said member to be inclined when the underlying pipe T is already partly curved and then it is not tangent to the central point of the saddle member 6 between the lateral depressions 306 thereof.
  • the swing center is preferably situated substantially at the top side of pipe T, in order to avoid any sideward displacement.
  • the pipe-bending saddle member 6 is lifted up and the partly bent pipe T is advanced rightward or leftward as seen in figure 1, by one step of a length not much shorter that the length of the already bent section.
  • the above-described bending step is then repeated, and on carrying out this step, the previously bent pipe section provided with lateral protuberances T1 conforming to the depressions 306 in the pipe-bending saddle member 6, comes to be located in correspondence of a portion thereof, in which the cross-section of the toric surface 106 of the saddle member 6 is semi-circular in shape, with no lateral depressions. Therefore, this semi-circular portion in cross-section of the pipe-bending saddle member 6 promotes the re-sizing of the already bent section of the pipe, by eliminating its protuberances T1 due to the depressions 306.
  • the contact area between the previously bent pipe T and the pipe-bearing cradle member 4 is widened to such an extent as to prevent any excessive specific pressure from being generated, which would cause the narrowing of the pipe when the pressure of the pipebending saddle member 6 on the previously bent pipe T is increased to cause a further or the final bending thereof.
  • the pipe bending apparatus comprises also two sizing dies 14,16 shown in figures 14 to 16, which are meant for eliminating any ovality of the pipe T in correspondence of the bend TC. It is ascertained that the said ovality always appears in such a manner that the major axis of the ovalized cross-section of the pipe bend TC is perpendicular to the plane of said bend TC.
  • Each one of the two sizing dies 14,16 has a concave surface 114,116 corresponding to a part slightly smaller than 180 of a toric surface segment. The load of this toric surface substantially corresponds to the load of the pipe bend TC.
  • the cross-section of the said toric surface part is slightly lesser than a semicircle and has a radius that is slightly longer than the radius of the cross-section of the pipe bend TC.
  • the said two sizing dies 14,16 are arranged the one over the other with their concave toric surfaces 114,116 facing each other, and one of them is secured to the press base 1 and the other to the movable plate 2 of the press.
  • the said sizing dies 14,16 delimit in cross-section a substantially oval opening having its major axis horizontal and slightly longer than the diameter of the cross-section of the pipe bend TC, and its minor axis vertical and slightly shorter than the diameter of the cross-­section of the bend TC.
  • Each one of the said sizing dies 14,16 is prolonged at least one and preferably at both ends thereof tangentially to the pipe bend TC, and so to the toric surface, by a substantially rectilinear section 214,216 having its maximum extent in correspondence of the extrados of the pipe bend TC, and being reduced to nothing in correspondence of the intrados of said bend.
  • an ovalized pipe bend TC the said bend is inserted between the two sizing dies 14,16 so as to have the plane of the bend arranged horizontally.
  • the major axis of the oval cross-sectional shape of the pipe bend TC is arranged vertically, i.e., in correspondence of the minor axis of the oval opening between the two sizing dies 14,16, as shown by a dash-and-dot line in figure 14.
  • the rectlinear end prolongations 214,216 of the two sizing dies 14,16 can effect the sizing even of any rectilinear extremity or extremities TC ⁇ of the pipe bend TC. Therefore, the rectlinear extremity TC ⁇ of the pipe bend TC is inserted into, and compressed within one of the two end sections of the opening between the two dies 14,16, in correspondence of the rectilinear respective tangential prolongations 214,216 of said dies (figure 16).
  • the invention may be applied also to the bending of pipes having been preliminarily filled with water, after the tight sealing of their ends by means of welded plugs.
  • the water contained in the pipe before bending under pressure preferably under a pressure of about 1/4 of the pressure that the pipe can withstand.
  • Such an initial pressure of the water in the pipe is controlled, for example, by means of a pressure gauge connected to the water inflow union, and is restored in the course of the first bending steps, during which it tends to change owing to the alteration in the extrados portion of the bend. This control is effected until the water pressure in the pipe will be maintained in a practically constant condition.
  • bends can be obtained with a radius starting from about two or three times the diameter of the pipe, and the bends thus obtained present a very slight reduction of the pipe diameter, and a very slight ovality and distortion, so that they meet the strictest technological requirements.
EP87116269A 1986-11-21 1987-11-05 Metallrohrbiegemaschine Withdrawn EP0268891A1 (de)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
IT1258486 1986-11-21
IT12584/86A IT1201677B (it) 1986-11-21 1986-11-21 Apparecchiatura per la curvatura di tubi metallici

Publications (1)

Publication Number Publication Date
EP0268891A1 true EP0268891A1 (de) 1988-06-01

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ID=11141890

Family Applications (1)

Application Number Title Priority Date Filing Date
EP87116269A Withdrawn EP0268891A1 (de) 1986-11-21 1987-11-05 Metallrohrbiegemaschine

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EP (1) EP0268891A1 (de)
IT (1) IT1201677B (de)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN100518984C (zh) * 2007-10-31 2009-07-29 江苏沪宁钢机股份有限公司 圆管钢构件弧形冷弯成型模具
EP2090382A2 (de) * 2008-02-11 2009-08-19 Officine Metallurgiche Piemontesi S.p.A. Verfahren zum Kaltbiegen von Rohren und dergleichen
CN104438957A (zh) * 2014-11-29 2015-03-25 汝州郑铁三佳水泥制品有限公司 一种双钩箍筋机用压料装置
ITUB20159272A1 (it) * 2015-12-22 2017-06-22 MANZON Anna Metodo di lavorazione per tubi e tubi ottenuti con detto metodo.
CN113560386A (zh) * 2021-07-08 2021-10-29 嘉兴赛德家具股份有限公司 一种铝质杆件成型加工装置
CN117161761A (zh) * 2023-10-16 2023-12-05 广东弘锦科技有限公司 一种座椅弯管制作系统
US11911819B2 (en) 2022-02-24 2024-02-27 Futaba Industrial Co., Ltd. Shaping method and shaping device for double pipe

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR716470A (fr) * 1931-05-04 1931-12-21 Perfectionnements aux appareils à cintrer les tuyaux
US1948474A (en) * 1931-02-05 1934-02-20 American Welding Mfg Co Bending machine
FR889424A (fr) * 1942-05-20 1944-01-10 Weser Flugzeugbau Ges M B H Matrice pour le cintrage de tuyaux dans des presses
GB690007A (en) * 1951-03-08 1953-04-08 Wellington Tube Works Ltd Method and means for manufacturing pipe elbows or bending metal tubes
FR1034267A (fr) * 1951-03-21 1953-07-21 Cintrage de tubes de fort diamètre par poinçonnage et matriçage successifs
DE3218662A1 (de) * 1982-05-18 1983-11-24 Leybold-Heraeus GmbH, 5000 Köln Verfahren und vorrichtung zum biegen von rohren

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1948474A (en) * 1931-02-05 1934-02-20 American Welding Mfg Co Bending machine
FR716470A (fr) * 1931-05-04 1931-12-21 Perfectionnements aux appareils à cintrer les tuyaux
FR889424A (fr) * 1942-05-20 1944-01-10 Weser Flugzeugbau Ges M B H Matrice pour le cintrage de tuyaux dans des presses
GB690007A (en) * 1951-03-08 1953-04-08 Wellington Tube Works Ltd Method and means for manufacturing pipe elbows or bending metal tubes
FR1034267A (fr) * 1951-03-21 1953-07-21 Cintrage de tubes de fort diamètre par poinçonnage et matriçage successifs
DE3218662A1 (de) * 1982-05-18 1983-11-24 Leybold-Heraeus GmbH, 5000 Köln Verfahren und vorrichtung zum biegen von rohren

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN100518984C (zh) * 2007-10-31 2009-07-29 江苏沪宁钢机股份有限公司 圆管钢构件弧形冷弯成型模具
EP2090382A2 (de) * 2008-02-11 2009-08-19 Officine Metallurgiche Piemontesi S.p.A. Verfahren zum Kaltbiegen von Rohren und dergleichen
EP2090382A3 (de) * 2008-02-11 2010-06-23 Officine Metallurgiche Piemontesi S.p.A. Verfahren zum Kaltbiegen von Rohren und dergleichen
CN104438957A (zh) * 2014-11-29 2015-03-25 汝州郑铁三佳水泥制品有限公司 一种双钩箍筋机用压料装置
ITUB20159272A1 (it) * 2015-12-22 2017-06-22 MANZON Anna Metodo di lavorazione per tubi e tubi ottenuti con detto metodo.
CN113560386A (zh) * 2021-07-08 2021-10-29 嘉兴赛德家具股份有限公司 一种铝质杆件成型加工装置
CN113560386B (zh) * 2021-07-08 2023-02-17 嘉兴赛德家具股份有限公司 一种铝质杆件成型加工装置
US11911819B2 (en) 2022-02-24 2024-02-27 Futaba Industrial Co., Ltd. Shaping method and shaping device for double pipe
CN117161761A (zh) * 2023-10-16 2023-12-05 广东弘锦科技有限公司 一种座椅弯管制作系统
CN117161761B (zh) * 2023-10-16 2024-02-27 广东弘锦科技有限公司 一种座椅弯管制作系统

Also Published As

Publication number Publication date
IT1201677B (it) 1989-02-02
IT8612584A0 (it) 1986-11-21

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