EP0856367A2 - Formage par étirage de corps métalliques avec des mandrins interne polymériques - Google Patents

Formage par étirage de corps métalliques avec des mandrins interne polymériques Download PDF

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Publication number
EP0856367A2
EP0856367A2 EP98300707A EP98300707A EP0856367A2 EP 0856367 A2 EP0856367 A2 EP 0856367A2 EP 98300707 A EP98300707 A EP 98300707A EP 98300707 A EP98300707 A EP 98300707A EP 0856367 A2 EP0856367 A2 EP 0856367A2
Authority
EP
European Patent Office
Prior art keywords
mandrel
extrusion
end portions
longitudinally
bending
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Withdrawn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
EP98300707A
Other languages
German (de)
English (en)
Other versions
EP0856367A3 (fr
Inventor
Thomas J. Vansumeren
Robert P. Even
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.)
Howmet Aerospace Inc
Original Assignee
Aluminum Company of America
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
Priority claimed from US08/839,616 external-priority patent/US5735160A/en
Application filed by Aluminum Company of America filed Critical Aluminum Company of America
Publication of EP0856367A2 publication Critical patent/EP0856367A2/fr
Publication of EP0856367A3 publication Critical patent/EP0856367A3/fr
Withdrawn legal-status Critical Current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
    • B21D11/00—Bending not restricted to forms of material mentioned in only one of groups B21D5/00, B21D7/00, B21D9/00; Bending not provided for in groups B21D5/00 - B21D9/00; Twisting
    • B21D11/02—Bending by stretching or pulling over a die
    • 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
    • B21D9/00—Bending tubes using mandrels or the like
    • 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
    • B21D9/00—Bending tubes using mandrels or the like
    • B21D9/08—Bending tubes using mandrels or the like in press brakes or between rams and anvils or abutments; Pliers with forming dies

Definitions

  • the invention pertains to a process for shaping an elongated hollow metal body that is preferably an aluminum alloy extrusion. Shaped extrusions made by the process of the invention are used as vehicle body components.
  • Aluminum alloy extrusions have long been used as components of vehicles, including automobiles, trucks, boats and aircraft. Such extrusions are typically made by a process wherein a heated ingot or billet is forced through a die opening under pressure to form an elongated body such as a channel, tube or angle.
  • the extruded product is generally forced through a die at forces in the 500 to 15,000 ton range.
  • the extrusion exits the die at elevated temperatures on the order of 300°-1200°F.
  • the extruded product is then commonly solution heat treated and quenched.
  • the product may be made to various lengths, including lengths in excess of 150 feet, and may have any of a diverse variety of cross-sectional configurations.
  • extrusions In order for the extrusions to be suitable as vehicle body components such as automobile roof rails, they must be shaped into more complex configurations.
  • Some processes employed in the prior art for shaping aluminum alloy extrusions include bending, stretch-forming and stretch-wrap forming. These prior art processes perform adequately in instances where the degree of deformation is small or where dimensional tolerances are large. However, there is still a need for an improved shaping process when large deformations are required and dimensional tolerances are small.
  • a principal objective of the present invention is to provide a process for stretch-forming hollow metal bodies wherein polymeric mandrels are placed inside the bodies in order to prevent collapse of the bodies when they are bent.
  • a related objective of the invention is to provide a process for stretch-forming hollow metal bodies wherein the bodies undergo smaller deviations from desired dimensions than in the prior art.
  • the hollow metal bodies are preferably aluminum alloy extrusions.
  • Some preferred aluminum alloys for the extrusions of the invention are aluminum-copper alloys of the AA 2000 series, aluminum-magnesium-silicon alloys of the AA 6000 series and aluminum-zinc alloys of the AA 7000 series.
  • Extrusions preferred for use in the automotive and aircraft industries that may be stretch formed by the present invention include, but are not limited to, the AA 2024, 6013, 6061, 6063, 6009 and 7075 aluminum alloys.
  • Extrusions that are shaped in accordance with the invention are elongated hollow bodies having opposed longitudinal by spaced end portions.
  • the extrusions generally start with a substantially uniform cross section from end to end. Total length is generally about 44 to 120 inches (112 to 305 cm).
  • a solid polymeric first mandrel is mechanically inserted into a first end portion of the body.
  • a solid polymeric second mandrel is mechanically inserted into a second end portion.
  • the two mandrels preferably each extend longitudinally about half of the length of the body.
  • the polymeric mandrels are preferably made from solid polyurethane. In a particularly preferred embodiment, they each have a durometer hardness of about 90A or 70D.
  • the polymeric mandrels are molded into a desired size and shape by using one of the hollow bodies as a mold.
  • a hot molten mass of polyurethane is placed inside the body.
  • the polyurethane shrinks as it cools and cures, forming a solid shape that is smaller than the body interior.
  • the solid shape is then removed and cut into first and second mandrels of equal length.
  • a steel shank is fastened to a lateral end of each mandrel.
  • End portions of an extrusion are gripped by the jaws of opposed grippers and the extrusion is stretched longitudinally by pulling the end portions in opposite directions. Sufficient force is exerted on the grippers to exceed an elastic limit so that elongation through plastic deformation is initiated.
  • the extrusion While the extrusion is being stretched longitudinally, it is bent transversely of the direction of pulling. Bending is preferably accomplished by moving the extrusion forcibly against a forming die or shaping die. Sufficient force is exerted to impart a contour to the extrusion similar to the forming die contour.
  • the polymeric mandrels each have an outer wall adjacent an interior wall of the hollow body.
  • the mandrels support the interior wall during bending so that it does not collapse.
  • a die adjacent the hollow body bends it transversely of the direction of stretching. Then, the body is stretched again to relieve residual stress introduced by bending. This second stretch minimizes any tendency of the metal to spring back to its original shape because of a memory effect. Finally, the bending is relaxed.
  • Figure 1 is a schematic illustration of an apparatus for forming hollow metal bodies in accordance with the present invention.
  • Figure 2 is a perspective view of an aluminum alloy extrusion that has been formed in accordance with the invention.
  • aluminum alloy extrusions are stretch-formed into shapes that are useful as vehicle body components such as automobile roof rails.
  • a stretch-forming apparatus 10 for carrying out the process of the invention is shown in Figure 1.
  • the apparatus 10 includes a pair of opposed grippers or upper assemblies 11, 12 having jaws 13, 14 for gripping portions of an aluminum alloy extrusion 20.
  • a first jaw 13 grasps a first end portion 21 and a second jaw 14 grasps a second end portion 22 of the extrusion 20.
  • the jaws 13, 14 selectively grip and release the end portions 21, 22 upon command from an operator (not shown) of the apparatus 10.
  • the gripper assemblies 11, 12 are carried by guides or jackets 25, 26 extending from hydraulic cylinder assemblies 27, 28.
  • the guides 25, 26 support the gripper assemblies 11, 12.
  • the cylinder assemblies 27, 28 are carried by adjustable mountings to permit rotation in the direction of arrows A, B with respect to a forming die or shaping die 30.
  • the guides 25, 26 contain piston rods 31, 32 extending from the hydraulic cylinder assemblies 27, 28. After an aluminum extrusion 20 is mounted between the gripper assemblies 11, 12, the piston rods 31, 32 push solid polyurethane mandrels 35, 36 through open ends 37, 38 of the extrusion 20.
  • the mandrels 35, 36 each extend about halfway through the extrusion 20.
  • a steel shank 45, 46 attached to each mandrel 35, 36 extends laterally outwardly of the open ends 37, 38.
  • Guides 25, 26 adjacent the shanks 45, 46 stabilize the mandrels 35, 36 inside the extrusion 20 when it is stretched and bent as described below.
  • the mandrels 35, 36 each have an outer wall 40 adjacent an interior wall 41 of the extrusion 20. Although the mandrels 35, 36 are smaller than the end openings 37, 38 when the mandrels 35, 36 are inserted, a lubricant is applied through a fibrous wick (not shown) adjacent the outer wall 40 through openings in the guides 25, 26. The lubricant facilitates removal of the mandrels 35, 36 after the extrusion 20 is shaped. The openings 37, 38 in the extrusion 20 become smaller after stretching.
  • the jaws 13, 14 are tightened firmly over the end portions 21, 22. Then, the hydraulic cylinder assemblies 27, 28 stretch the extrusion 20 longitudinally by pulling on the guides 25, 26. After stretching is initiated, the gripper assemblies 11, 12 swing as indicated by the arrows A, B to form the extrusion 20 over the forming die 30.
  • the extrusion 20 is bent transversely to a desired degree, the extrusion 20 is stretched again by the cylinder assemblies 27, 28 to relieve residual stresses introduced by bending. This second stretch minimizes any tendency of the metal extrusion 20 to spring back to its original shape.
  • a shaped extrusion 80 made in accordance with our invention is shown in Figure 2.
  • the extrusion 80 has a first end portion 81, a second end portion 82 and a center portion 83.
  • the first end portion 81 has a bend radius of about 7 times the part depth (7D bend).
  • the second end portion 82 has a bend radius of about 4 times the part depth (4D bend).
  • the center portion 83 has a bend radius of about 65 times the part depth (65D bend).
  • Our experience with prior art bending methods is that dimensional tolerance problems are to be expected in the end portions 81, 82 because of their tighter bend radii.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Bending Of Plates, Rods, And Pipes (AREA)
  • Shaping Of Tube Ends By Bending Or Straightening (AREA)
  • Shaping By String And By Release Of Stress In Plastics And The Like (AREA)
EP98300707A 1997-01-31 1998-01-30 Formage par étirage de corps métalliques avec des mandrins interne polymériques Withdrawn EP0856367A3 (fr)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
US3679897P 1997-01-31 1997-01-31
US36798P 1997-01-31
US839616 1997-04-15
US08/839,616 US5735160A (en) 1997-04-15 1997-04-15 Stretch forming metal bodies with polymeric internal mandrels

Publications (2)

Publication Number Publication Date
EP0856367A2 true EP0856367A2 (fr) 1998-08-05
EP0856367A3 EP0856367A3 (fr) 2001-01-31

Family

ID=26713514

Family Applications (1)

Application Number Title Priority Date Filing Date
EP98300707A Withdrawn EP0856367A3 (fr) 1997-01-31 1998-01-30 Formage par étirage de corps métalliques avec des mandrins interne polymériques

Country Status (2)

Country Link
EP (1) EP0856367A3 (fr)
JP (1) JPH10263712A (fr)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2000076683A1 (fr) * 1999-06-09 2000-12-21 Thyssen Krupp Stahl Ag Mandrin de cintrage pour un dispositif de cintrage, et procede de cintrage de tuyaux
GB2442793A (en) * 2006-10-10 2008-04-16 Apogee Antennas Ltd Forming curved panels
CN102228921A (zh) * 2011-04-21 2011-11-02 吉林大学 新一代高速动车铝合金端墙柱构件成形方法
DE102014107389A1 (de) * 2014-05-26 2015-11-26 Viega Gmbh & Co. Kg Innenbiegewerkzeug für Rohre
CN105195622A (zh) * 2015-10-26 2015-12-30 浙江志达管业有限公司 管制弯头冲压成型模具
WO2018006113A1 (fr) * 2016-07-07 2018-01-11 Fill Gesellschaft M.B.H. Machine de formage par étirage et procédé de mise en forme d'une pièce
CN109513793A (zh) * 2018-12-29 2019-03-26 西南铝业（集团）有限责任公司 一种槽型型材拉伸工艺及拉伸矫直设备和垫块

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP5541684B2 (ja) * 2010-01-29 2014-07-09 株式会社神戸製鋼所 アルミニウム合金の中空押出形材のプレス曲げ加工方法

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3580044A (en) * 1969-03-24 1971-05-25 Edwin A De Voss Tube bending mandrel
JPS60206535A (ja) * 1984-03-31 1985-10-18 Hashimoto Forming Co Ltd モ−ルデイング類の曲げ加工装置
US5327765A (en) * 1993-04-05 1994-07-12 Aluminum Company Of America Internal articulated mandrel for the stretch forming of elongated hollow metal sections
US5351517A (en) * 1991-12-10 1994-10-04 Spaeth Walter Method of, and a machine for, stretching and bending a profiled length of material
US5502997A (en) * 1994-12-19 1996-04-02 Carrier Corporation Gripper and mandrel assembly for tube bender
EP0826440A1 (fr) * 1996-08-30 1998-03-04 Gec Alsthom Acb Equipement pour le formage de profilés métalliques

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3580044A (en) * 1969-03-24 1971-05-25 Edwin A De Voss Tube bending mandrel
JPS60206535A (ja) * 1984-03-31 1985-10-18 Hashimoto Forming Co Ltd モ−ルデイング類の曲げ加工装置
US5351517A (en) * 1991-12-10 1994-10-04 Spaeth Walter Method of, and a machine for, stretching and bending a profiled length of material
US5327765A (en) * 1993-04-05 1994-07-12 Aluminum Company Of America Internal articulated mandrel for the stretch forming of elongated hollow metal sections
US5502997A (en) * 1994-12-19 1996-04-02 Carrier Corporation Gripper and mandrel assembly for tube bender
EP0826440A1 (fr) * 1996-08-30 1998-03-04 Gec Alsthom Acb Equipement pour le formage de profilés métalliques

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
PATENT ABSTRACTS OF JAPAN vol. 010, no. 059 (M-459), 8 March 1986 (1986-03-08) -& JP 60 206535 A (HASHIMOTO FORMING KOGYO KK), 18 October 1985 (1985-10-18) *

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2000076683A1 (fr) * 1999-06-09 2000-12-21 Thyssen Krupp Stahl Ag Mandrin de cintrage pour un dispositif de cintrage, et procede de cintrage de tuyaux
DE19926330A1 (de) * 1999-06-09 2000-12-21 Thyssenkrupp Stahl Ag Biegedorn für eine Biegevorrichtung und Biegeverfahren für Rohre
DE19926330C2 (de) * 1999-06-09 2001-08-09 Thyssenkrupp Stahl Ag Biegedorn für eine Biegevorrichtung und Biegeverfahren für Rohre
GB2442793A (en) * 2006-10-10 2008-04-16 Apogee Antennas Ltd Forming curved panels
CN102228921A (zh) * 2011-04-21 2011-11-02 吉林大学 新一代高速动车铝合金端墙柱构件成形方法
DE102014107389A1 (de) * 2014-05-26 2015-11-26 Viega Gmbh & Co. Kg Innenbiegewerkzeug für Rohre
CN105195622A (zh) * 2015-10-26 2015-12-30 浙江志达管业有限公司 管制弯头冲压成型模具
WO2018006113A1 (fr) * 2016-07-07 2018-01-11 Fill Gesellschaft M.B.H. Machine de formage par étirage et procédé de mise en forme d'une pièce
CN109513793A (zh) * 2018-12-29 2019-03-26 西南铝业（集团）有限责任公司 一种槽型型材拉伸工艺及拉伸矫直设备和垫块
CN109513793B (zh) * 2018-12-29 2023-05-23 西南铝业（集团）有限责任公司 一种槽型型材拉伸工艺及拉伸矫直设备

Also Published As

Publication number Publication date
JPH10263712A (ja) 1998-10-06
EP0856367A3 (fr) 2001-01-31

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