US3852987A - Forming transverse corrugations in a tubular blank - Google Patents

Forming transverse corrugations in a tubular blank Download PDF

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Publication number
US3852987A
US3852987A US00339198A US33919873A US3852987A US 3852987 A US3852987 A US 3852987A US 00339198 A US00339198 A US 00339198A US 33919873 A US33919873 A US 33919873A US 3852987 A US3852987 A US 3852987A
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United States
Prior art keywords
mandrel
centre
centre mandrel
corrugations
toothed wheels
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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
Application number
US00339198A
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English (en)
Inventor
S Price
T Plummer
R Fowler
E Harrington
E Hill
C Woodwards
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Motors Liquidation Co
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General Motors Corp
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Filing date
Publication date
Application filed by General Motors Corp filed Critical General Motors Corp
Priority to IT4909574A priority Critical patent/IT1011039B/it
Priority to IT4909374A priority patent/IT1011038B/it
Application granted granted Critical
Publication of US3852987A publication Critical patent/US3852987A/en
Anticipated expiration legal-status Critical
Expired - Lifetime 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
    • B21D15/00—Corrugating tubes
    • B21D15/04—Corrugating tubes transversely, e.g. helically
    • B21D15/06—Corrugating tubes transversely, e.g. helically annularly

Definitions

  • the mandrel is made up of a series of like elongate segments which are arranged around an expander plug and are selectively held in an expanded operative condition, or allowed to collapse radially inwardly for removal of the corrugated tubular member, by axial movement of the expander plug.
  • Spring-loaded detent balls co-operate with the teeth of the individual toothed wheels to ensure correct initial positioning.
  • corrugations which vary along the length of the tubular member can be produced by mounting the toothed wheels of the die assembly in slide members,
  • the invention envisages the use of an elongate segmental collapsible centre mandrel formed externally with transverse corrugations substantially corresponding to those to be formed in a tubular blank, and a die assembly comprising a ring of toothed wheels which extend radially of the longitudinal axis of the centre mandrel and are rotatably mounted in a common holder with the axes of rotation of the rollers disposed in a common radial plane of the longitudinal axis of the centre mandrel, the circular pitch of the teeth of each wheel being equal to the linear pitch of the transverse corrugations of the centre mandrel, whereby, on relative axial displacement of the centre mandrel and the die assembly, with a tubular blank in position on the transverse corrugations of the centre mandrel, successive teeth of the ring of wheels index with successive corrugations of the centre mandrel with a rack and pinion action, to thereby cause progressive formation of transverse corrugations in the interposed tubular blank
  • a method in accordance with the invention for forming transverse corrugations in a tubular blank comprises: positioning the blank on an externally transversely corrugated portion of an elongate segmental centre mandrel, the transverse corrugations on which substantially correspond to those to be formed in the tubular blank; effecting relative axial displacement of the centre mandrel and blank and a die assembly comprising a ring of toothed wheels which extend radially around the longitudinal axis of the centre mandrel and are rotatably mounted in a common holder with the axes of rotation of the rollers disposed in a common radial plane of the longitudinal axis of the centre mandrel, the circular pitch of the teeth of each wheel being equal to the linear pitch of the corrugations of the centre mandrel, such that the relative axial displacement ofthe centre mandrel and the die assembly causes progressive formation of transverse corrugations in the interposed tubular blank as successive teeth of each of the wheels index with successive corrugations of the centre mandrel with
  • Apparatus in accordance with the invention for forming transverse corrugations in a tubular blank comprises an elongate segmental centre mandrel formed externally with transverse corrugations substantially corresponding to those to be formed in the tubular blank, and a die assembly comprising a ring of toothed wheels which extend radially of the longitudinal axis of the centre mandrel and are rotatably mounted in a common holder with the axes of rotation of the rollers disposed in a common radial plane of the longitudinal axis of the centre mandrel, the circular pitch of the teeth of each wheel being equal to the linear pitch of the transverse corrugations of the centre mandrel, the
  • the apparatus also comprising means actuable to effect collapse of the segmental centre mandrel for removal of the resulting transversely corrugated tubular member.
  • toothed wheels will be identical in size and configuration.
  • spring-loadedballs or other detent arrangements are conveniently mounted on the die assembly and arranged to co-operate with adjacent teeth of the respective toothed wheels.
  • An abutment specifically the leading external transverse corrugation on the centre. mandrel, is conveniently used for the initial feeding-in of the tubular blank to the circular throat (nip" region) between the centre mandrel and the toothed wheels.
  • the extra material required for forming the corrugations can be allowed to flow over the centre mandrel from the free end, namely the opposite end to the abutment.
  • either one of these may be moved, and the other will generally be maintained stationary.
  • the centre mandrel may be moved and the die assembly may be maintained stationary, or the die assembly may be moved and the centre mandrel maintained stationary.
  • the tubular blank will generally be made of metal, which may be ferrous metal, for example steel, or nonferrous metal, for example aluminum or copper or a copper alloy.
  • the metal of the blank may be annealed or subjected to other heat treatment before or after formation of the corrugations, depending on the properties required, and correspondingly'the wall thickness,
  • the corrugated length, and the composition of the blank may be varied, depending on the properties required in the resulting corrugated tubular member.
  • the tubular blank (and correspondingly the centre mandrel) will generally have a circular cross-section, although a polygonal cross-section would alternatively be feasible.
  • the crests of the teeth of the toothed wheels are preferably concave between the tooth flanks, with the same curvature as the circular crests of the transverse corrugations of the centre mandrel.
  • the number of toothed wheels is preferably the same as the number of segments of the centre mandrel, with the gaps between the inner peripheries of the toothed wheels (at the throat of the die assembly) being radially aligned with the gaps between the individual segments of the centre mandrel, whereby good resistance of the resulting corrugated tubular member to bending forces can be achieved.
  • tubular blank is not to be corrugated throughout its length, it may have one or both of its end portions of reduced diameter, formed for example by the use of swaging dies. This is normally required for instance in the case of tubes to be used for energyabsorbing steering columns, to allow bearings or tube extensions (for example) to be fitted.
  • the centre mandrel may be disposed in a vertical position or in a horizontal (or other) position.
  • hydraulic or mechanical means may be used.
  • the centre mandrel may have a circular external cross-section and be made up of a plurality of like segments which surround an expander plug that is slidably mounted in a mandrel support housing, with the expander plug including a full-diameter generally cylindrical portion which in a first position of the expander plug holds the segments of the centre mandrel in an expanded, operative position, means being provided to limit radially outward movement of the seg ments of the centre mandrel, and the expander plug may also include a smaller-diameter portion which, on actuation of the expander plug into a second position, permits collapse of the centre mandrel by generally radially inward movement of the mandrel segments towards a position of engagement with the smallerdiameter portion of the expander plug, for removal of the transversely corrugated tubular member
  • the invention also comprehends an energyabsorbing steering column for a motor vehicle, comprising a steering shaft which is collapsible axially in response to impact forces, and a transversely corrugated tubular member as aforesaid connected as ajacket tube for the collapsible steering shaft, such that energy of an impact is in effect absorbed by conversion into the deformation force required for axial collapse of the corrugations.
  • FIG. 1 is a fragmentary longitudinal section showing one embodiment of apparatus in accordance with the present invention for forming transverse corrugations in a tubular blank;
  • FIG. 2 is a plan view, with parts broken away, of a die assembly forming part of the apparatus shown in FIG.
  • FIG. 3 is a local cross-section of a segmental centre mandrel forming part of the apparatus shown in FIG. I;
  • FIGS. 4a, 4b and 4c illustrate schematically three stages in the production of a corrugated tube using the apparatus of FIG. 1.
  • FIG. I of the drawings com prises an elongate segmental centre mandrel l0, and a die assembly 12 comprising a ring of eight toothed wheels 14 which are rotatably mounted in a common holder 16 (seen best in FIG. 2).
  • the centre mandrel is formed externally with transverse corrugations l8 (circumferential corrugations) substantially corresponding to those to be formed in the tubular blank.
  • the centre mandrel 10 has a circular cross-section, and is made up of eight like segments 20 (shown in FIG. 3) surrounding an expander plug 22 which is slidably mounted in a mandrel support housing 24 by way of a guide bush 26.
  • a relatively large-diameter portion 28 of the expander plug holds the segments 20 of the centre mandrel 10 in their expanded, operative position (as is also illustrated in FIG.
  • the die assembly 12 including the ring of eight toothed wheels 14 rotatably mounted in the common holder 16 is disposed coaxially with respect to the longitudinal axis of the centre mandrel 10, with the toothed wheels 14 being arranged around the longitudinal axis of the centre mandrel in a symmetrical fashion, as is shown most clearly in FIG. 2, the arrangement being such that the toothed wheels are disposed in respective longitudinally extending radial planes of the longitudinal axis of the centre mandrel.
  • the eight toothed wheels 14 are mounted on individual shafts 38 so as to be rotatable independently of one another, and correspondingly eight resilient detents in the form of springloaded ball plungers 40 are mounted in respective bores of the holder 16 and co-operate with adjacent teeth of the respective toothed wheels 14 to ensure correct initial positioning of all the toothed wheels, such as to maintain the teeth of each wheel initially in register with the teeth of all the other wheels.
  • the crests of the teeth of the toothed wheels 14 are concave between the tooth flanks, with the same curvature as the circular crests of the transverse corrugations of the centre mandrel, there being a slight chamfer at the tooth flanks to give a good fit at the circular throat formed by the ring of toothed wheels, with only a small gap between the teeth of adjacent wheels.
  • the gaps between the teeth of the adjacent wheels 14 are radially aligned with the gaps between the segments 20 of the centre mandrel 10.
  • the circular pitch of the teeth of the toothed wheels 14 is equal to the linear pitch of the transverse corrugations of the centre mandrel.
  • FIG. 4 To produce a corrugated tubular blank for use as an energy-absorbing member in an energy-absorbing steering column for a motor vehicle, the procedure is as is illustrated in FIG. 4. Initially, a tubular blank 42 of appropriate length is parted off from steel tube stock, and the ends of the blank are de-burred. By the use of swaging dies, the end portions of the tubular blank are reduced in diameter to provide cylindrical portions to which bearings or tube extensions can subsequently be fitted, thereby also forming annular shoulders between the respective reduced-diameter end portions and the full-diameter portion of the tubular blank.-
  • the resulting pre-formed tubular blank (component tube) 44 is then formed with transverse corrugations on its full-diameter portion in the apparatus which has been described, to provide the required corrugated tubular member 46.
  • the pre-formed tubular blank 44 is positioned around the external transversely corrugated portion 18 of the collapsed centre mandrel 10, with one of its shoulders abutted to the leading external transverse corrugation on the centre mandrel, and the centre mandrel is expanded, whereupon, by means of a press arrangement (not shown), relative axial displacement of the expanded centre mandrel and tubular blank, and the die assembly 12, is effected towards one another, specifically by displacing the die assembly upwardly along the centre mandrel.
  • the die assembly When the required number of corrugations has been formed along the full-diameter portion of the tubular blank, the die assembly is withdrawn to its original position, and the expander plug is withdrawn to allow the centre mandrel to collapse, whereupon the corrugated tube member can be removed from the centre mandrel.
  • gitudinal ribs increase the bending strength of the corrugated tube member, so increasing the likelihood of the corrugated tube membercollapsing in straight-line I fashion under impact conditions.
  • the transverse corrugations in the corrugated tube members may be desirable to vary the physical characteristics (primarily the strength) of the transverse corrugations in the corrugated tube members, either progressively or intermittently throughout the length of the corrugated portion of the tube member.
  • This can be done by having the individual toothed wheels and their supporting shafts held in respective slide members which are mounted separately in a common holder, with actuation of the slide members in a generally radially inward direction (that is, towards the longitudinal axis of the centre mandrel) by means of an annular cam ring.
  • the cam ring could for instance be actuated by a barrel-type cam, for variation in the form of the successive corrugations to a predetermined pattern.
  • a method of forming transverse corrugations in a tubular blank comprising positioning the blank on an externally transversely corrugated portion of an elongate segmental centre mandrel, the transverse corrugations on which substantially correspond to those to be formed in the tubular blank; effecting relative axial displacement of the centre mandrel and blank and a die assembly comprising a-ring of toothed wheels which extend radially of the longitudinal axis of the centre mandrel and are rotatablymounted in a'common holder with the axes of rotation of the toothed wheels disposed in a common radial plane of the longitudinal axis of the centre mandrel, the circular pitch of the teeth of'each Wheel being equal to the linear pitch of the corrugations of the centre mandrel, such that the relative axial displacement of the centre mandrel and the die assembly causes progressive formation of transverse corrugations in the interposed tubular blank as successive teeth of each of the wheels index with successive corrugations of the centre mandrel
  • a method of forming transverse corrugations in. a tubular metal blank that includes a full-diameter generally cylindrical portion separated, towards at least one end of the blank, by an annular shoulder from a lesserdiameter generally cylindrical end portion comprising positioning the blank coaxially on an externally transversely corrugated portion of an elongate centre mandrel, with the said annular shoulder in register with a leading external transverse corrugation on the centre mandrel, effecting relative axial displacement of the centre mandrel and blank and a dieasser'nbly comprising a ring of toothed wheels which extend radially of the longitudinal axis of the centre mandrel and are rotatably mounted in a common holder with their axes of rotation disposed in a common radial plane of said axis, the circular pitch of the teeth of each wheel being equal to the linear pitch of the corrugations of the centre mandrel, such that said relative axial diplacement causes progressive formation of transverse corrug
  • Apparatus for forming transversecorrugations in a tubular blank comprising an elongate segmental cen tre mandrel formed externally with transversecorrugations substantially corresponding to those to be formed in the tubular blank, a die assembly comprising a ring of toothed wheels which extend radially of the longitudinal axis of the centre mandrel and are rotatably mounted in a common holder with the axes of rotation of the toothed wheels disposed in a common radial plane of said axis, the circular pitch of the teeth of each wheel being equal to the linear pitch of the transverse corrugations of the centre mandrel, means for positioning all the toothed wheels in an initial position, means for effecting relative axial displacement of the centre mandrel and the die assembly whereby, with a tubular blank as aforesaid held in register with the centre mandrel around the transverse corrugations thereof, progressive formation of transverse corrugations in the interposed tubular blank is effected as successive teeth
  • Apparatus for forming transverse corrugations in a tubular blank having a circular cross-section comprising an elongate segmental centre mandrel which correspondingly has a circular crosssection and is formed externally with transverse corrugations substantially corresponding to those to be formed in the tubular blank, a die assembly comprising a ring of toothed wheels which extend radially of the longitudinal axis of the centre mandrel and are rotatably mounted in a common holder with the axes of rotation of the toothed wheels disposed in a common radial plane of said axis, the teeth of the toothed wheels having crests which are concave between the tooth flanks with a curvature which is the same as the curvature of the transverse corrugations of the centre mandrel, and the circular pitch ofthe teeth of each wheel being equal to the linear pitch of the transverse corrugations of the centre mandrel, spring-loaded ball detent arrangements mounted on the die assembly for co-operation with adjacent teeth of the die
  • Apparatus for forming transverse corrugations in a tubular blank having a circular cross-section comprising an elongate segmental centre mandrel which has a circular cross-section and is formed externally with transverse corrugations, a die assembly comprising a number of toothed wheels which is the same as the number of the segments of the centre mandrel, the toothed wheels extending radially of the longitudinal axis ofthe centre mandrel and being rotatably mounted in a common holder portion of the die assembly with the axes of rotation of the toothed wheels disposed in a common radial plane of said axis and with gaps between the inner peripheries of the toothed wheels being radially aligned with respective gaps between the individual segments of the centre mandrel, the teeth of the toothed wheels having crests which are concave between the tooth flanks'with a curvature which is the same as the curvature of the transverse corrugations of the centre mandrel, the circular
  • Apparatus for forming transverse corrugations in a tubular blank having a circular cross-section comprising an elongate centre mandrel which has a circular external cross-section and is made up of a plurality of circumferentially spaced elongate like segments, a mandrel support housing, an expander plug that is slidably mounted in a generally vertical position in the mandrel support housing and is surrounded by said mandrel segments, said expander plug including a fulldiameter generally cylindrical portion which in a first position of the expander plug holds the segments of the centre mandrel in an expanded, operative position,
  • the apparatus also comprising a die assembly having a ring of toothed wheels which extend radially of the longitudinal axis of the centre mandrel and are individually rotatably mounted in a common holder forming part of the die assembly with the axes of rotation of the toothed wheels disposed in a common radial plane of said axis, the circular pitch of the teeth of each wheel being equal to the linear pitch of the transverse corrugations of the centre mandrel, detent means for positioning all the toothed Wheels in corresponding initial positions, means'for effecting upward displacement of the die assembly with the centre man

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Bending Of Plates, Rods, And Pipes (AREA)
  • Shaping Metal By Deep-Drawing, Or The Like (AREA)
US00339198A 1972-03-18 1973-03-08 Forming transverse corrugations in a tubular blank Expired - Lifetime US3852987A (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
IT4909574A IT1011039B (it) 1973-03-08 1974-03-07 Dispositivo di fissaggio per fregi applicabili alla carrozzeria di au tovetture
IT4909374A IT1011038B (it) 1973-03-07 1974-03-07 Cassa d afflusso perfezionata per macchina per la fabbricadispositivo di fissaggio per fregi applicabili alla carrozzeria di au tovetture zione di carta

Applications Claiming Priority (1)

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GB1277872A GB1370700A (en) 1972-03-18 1972-03-18 Forming transverse corrugations in a tubular blank

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US (1) US3852987A (enrdf_load_stackoverflow)
AU (1) AU462884B2 (enrdf_load_stackoverflow)
DE (1) DE2309215C3 (enrdf_load_stackoverflow)
FR (1) FR2176707B1 (enrdf_load_stackoverflow)
GB (1) GB1370700A (enrdf_load_stackoverflow)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20040231395A1 (en) * 2001-07-05 2004-11-25 Barber Mark W. Method for expanding a tubular blank
US6826943B2 (en) * 2000-08-29 2004-12-07 Hydro Alumunium Deutschland Gmbh Process for forming tube-shaped hollow bodies made of metal
CN102900201A (zh) * 2012-10-22 2013-01-30 沈阳建筑大学 浆锚式钢筋连接套筒及其制造模具和制造方法
CN102000734B (zh) * 2009-08-31 2014-04-02 扬州恒德模具有限公司 一种点冲成型模具

Families Citing this family (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2617415B1 (fr) * 1987-07-02 1991-08-09 Nacam Procede et dispositif pour le faconnage par martelage d'un tube a ondes et son application a des tubes pour l'industrie automobile
DE19636424A1 (de) * 1996-09-07 1998-03-12 Audi Ag Vorrichtung zur Herstellung von Konturen in der Wandung eines Hohlprofiles
DE19710071A1 (de) * 1997-03-12 1998-09-24 Alsthom Cge Alcatel Vorrichtung zum Ringwellen von Rohren
RU2176168C2 (ru) * 1998-06-01 2001-11-27 Открытое акционерное общество "Белгородский завод энергетического машиностроения" Устройство для гофрирования обечаек
RU2205715C2 (ru) * 2001-06-15 2003-06-10 Лыткин Игорь Никитич Устройство для гофрирования труб
RU2225766C1 (ru) * 2003-04-30 2004-03-20 Мишулин Аристоник Александрович Способ изготовления труб с винтовыми гофрами
RU2382974C1 (ru) * 2009-02-24 2010-02-27 Общество с ограниченной ответственностью "Завод теплогидроизолированных труб" Способ изготовления теплообменной трубы
CN109058347B (zh) * 2018-02-05 2020-09-04 杭州富阳新远新能源有限公司 一种可变摩擦力阻尼器的汽车减震器

Citations (5)

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Publication number Priority date Publication date Assignee Title
US12346A (en) * 1855-02-06 Current water-wheel
DE851791C (de) * 1950-10-14 1952-10-09 Schumag Schumacher Metallwerke Vorrichtung zum Rillen von Rohrdraehten u. dgl.
US2614607A (en) * 1948-10-01 1952-10-21 Klein Otto Apparatus for corrugating tubes
US2714919A (en) * 1951-03-20 1955-08-09 John M Johnston Apparatus and method for forming seamless flexible tubing
US2736284A (en) * 1950-09-02 1956-02-28 Walker Mfg Company Of Wisconsi Muffler shell forming machine

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1272865B (de) * 1964-01-31 1968-07-18 Siemens Ag Vorrichtung zur fortlaufenden Herstellung in sich geschlossener Rillen an Rohren

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US12346A (en) * 1855-02-06 Current water-wheel
US2614607A (en) * 1948-10-01 1952-10-21 Klein Otto Apparatus for corrugating tubes
US2736284A (en) * 1950-09-02 1956-02-28 Walker Mfg Company Of Wisconsi Muffler shell forming machine
DE851791C (de) * 1950-10-14 1952-10-09 Schumag Schumacher Metallwerke Vorrichtung zum Rillen von Rohrdraehten u. dgl.
US2714919A (en) * 1951-03-20 1955-08-09 John M Johnston Apparatus and method for forming seamless flexible tubing

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6826943B2 (en) * 2000-08-29 2004-12-07 Hydro Alumunium Deutschland Gmbh Process for forming tube-shaped hollow bodies made of metal
US20040231395A1 (en) * 2001-07-05 2004-11-25 Barber Mark W. Method for expanding a tubular blank
US7013697B2 (en) * 2001-07-05 2006-03-21 Magna Structural Systems, Inc. Method for expanding a tubular blank
CN102000734B (zh) * 2009-08-31 2014-04-02 扬州恒德模具有限公司 一种点冲成型模具
CN102900201A (zh) * 2012-10-22 2013-01-30 沈阳建筑大学 浆锚式钢筋连接套筒及其制造模具和制造方法
CN102900201B (zh) * 2012-10-22 2015-07-08 沈阳建筑大学 浆锚式钢筋连接套筒的制造模具和制造方法

Also Published As

Publication number Publication date
DE2309215B2 (de) 1974-01-03
DE2309215A1 (de) 1973-10-04
FR2176707B1 (enrdf_load_stackoverflow) 1975-10-31
AU5254473A (en) 1974-08-29
DE2309215C3 (de) 1978-06-29
GB1370700A (en) 1974-10-16
FR2176707A1 (enrdf_load_stackoverflow) 1973-11-02
AU462884B2 (en) 1975-07-10

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