WO2007120564A2 - Améliorations apportées à des pièces de machine soumises à un fractionnement - Google Patents

Améliorations apportées à des pièces de machine soumises à un fractionnement Download PDF

Info

Publication number
WO2007120564A2
WO2007120564A2 PCT/US2007/008490 US2007008490W WO2007120564A2 WO 2007120564 A2 WO2007120564 A2 WO 2007120564A2 US 2007008490 W US2007008490 W US 2007008490W WO 2007120564 A2 WO2007120564 A2 WO 2007120564A2
Authority
WO
WIPO (PCT)
Prior art keywords
piece
crack
stress riser
machine component
improvement
Prior art date
Application number
PCT/US2007/008490
Other languages
English (en)
Other versions
WO2007120564A3 (fr
Inventor
Timothy E. Geiman
Original Assignee
Gkn Sinter Metals, Inc.
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 Gkn Sinter Metals, Inc. filed Critical Gkn Sinter Metals, Inc.
Publication of WO2007120564A2 publication Critical patent/WO2007120564A2/fr
Publication of WO2007120564A3 publication Critical patent/WO2007120564A3/fr

Links

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
    • F16C9/00—Bearings for crankshafts or connecting-rods; Attachment of connecting-rods
    • F16C9/04—Connecting-rod bearings; Attachments thereof
    • F16C9/045—Connecting-rod bearings; Attachments thereof the bearing cap of the connecting rod being split by fracturing
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F5/00—Manufacture of workpieces or articles from metallic powder characterised by the special shape of the product
    • B22F5/003—Articles made for being fractured or separated into parts
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
    • F16C7/00—Connecting-rods or like links pivoted at both ends; Construction of connecting-rod heads
    • F16C7/02—Constructions of connecting-rods with constant length
    • F16C7/023—Constructions of connecting-rods with constant length for piston engines, pumps or the like

Definitions

  • This invention relates to machine components that are made in one piece, separated and put back together in a precise position of the two separated pieces relative to one another, such as connecting rods.
  • connection rods Certain machine components, most notably connecting rods, are made in one piece and then split along a parting face so as to be put back together along that face for continued manufacturing operations such as machining.
  • the bearing cap portion of the connecting rod is split off from the main rod portion along a diametral line of the crank bore of the rod.
  • a notch is formed during the compacting process on each side of the crank bore, adjacent to the bolt holes that hold the bearing cap to the rod portion of the connecting rod. When forging, the notch closes to become a controlled ans stress concentrating crease or slit, but oxidation on the facing surfaces of the slit prevent it from being completely welded closed.
  • the slits initiate the splitting of the bearing cap from the rod portion of the connectine rod.
  • the cracking starts from the inside, which is where the initiating slit is, and moves outwardly.
  • the cracking reaches the bolt hole that is used to fasten the bearing cap to the rod portion post-fracture, it must proceed around both sides of the bolt hole, which can sometimes result in inconsistent crack propagation.
  • U. S. Patent No. 4,923,674 discloses forming two crack path notches in the inside of the bolt holes to try to achieve more consistent results, which requires a post compaction or forging machining operation.
  • U. S. Patent Nos. 5,594,187 and 5,613,182 provide a different proposal, which is to form a stress riser crease in a side surface of the connecting rod, rather than at the bore, and is not believed to have found wide acceptance.
  • the present invention provides other solutions for achieving more consistent results in the crack propagation from an initiating slit in a fracture split machine component.
  • the present invention provides control of the crack direction after initiation resulting in more predictable and consistent crack propagation.
  • a target notch directly opposite from the starter notch is formed in the component.
  • One option is to make the pre-forging by powder metal compaction, such that the starter and target notches close when the component is forged, but do not re-weld either due to oxidation of the surfaces of the notch.
  • Another tactic to prevent re-welding is coating the pre-forging with graphite or some other weld-inhibiting substance, either completely or locally, prior to forging to ensure that the surfaces of the notch do not join with one another.
  • the intent of the target notch is to help direct the propagating crack to consistently end at the target notch, making mismatch and/or breakout of the surface of the component where the crack ends less likely.
  • a target slot of various shapes can be formed in the forged part to reduce the wall thickness in the section where the crack is intended to propagate. This should serve to direct the propagation in a predictable and consistent manner.
  • the desired area of fracture splitting can be made with a more brittle material. This can be done in the compaction of a powder metal compact by simply using a more brittle powder metal material in the desired zone of crack propagation.
  • the material is chosen to be compatible with the other more ductile material of the connecting rod so a multiple material connecting rod is made.
  • the same material can be used but of a lower density, which makes that zone more brittle.
  • the notch formed in the compact is made deep enough to intersect the bolt hole.
  • crack propagation is directed toward target zones which are formed by selectively applying near surface residual stresses.
  • One method is forming areas of high residual stresses on either side of the target zone by needle peening. Needle peening has the effect of increasing the near surface residual stresses, which helps direct the propagating crack to the zone without the residual stresses.
  • a notch or slot is formed completely or nearly completely around the peripheral edge of the desired fraction separation plane. In the case of a connecting rod, that is around the legs of the connecting rod, between the cap and the remaining portion of the connecting rod, where the fracture is desired to occur.
  • brittle materials can be combined with inner and outer notches or slots, or with fracture separation plane edge notches, or with needle peening, or deep slots.
  • FIG. 1 is a perspective view of a connecting rod preform (prior to forging) of a first embodiment of the invention having target notches in the front and rear surfaces of the connecting rod opposite from the initiating notches provided in the crank bore;
  • Fig. 2 is a view similar to Fig. 1 , but with target slots rather than notches;
  • Fig. 3 is a view similar to Fig. 1, but with zones of more brittle or lower density material and no target notches or slots;
  • Fig. 4 is a view like Fig. 1, but with no target notches but a deep initiating notch that extends into the bolt holes;
  • Fig. 5 is a view like Fig. 1, but without target notches and with peened areas with a target area between them; and
  • Fig. 6 is a view like Fig. 1, but with a crack propagation directing notch formed all the way around the legs of the connecting rod at the desired fracture plane between the bearing cap and the rod portion of the connecting rod.
  • FIG. 1 illustrates a connecting rod preform 10 having a rod portion 12 and a bearing cap 14.
  • a crank bore 16 has its upper half defined in the rod portion 12 and its lower half defined in the cap 14.
  • Initiating stress risers 18 and 20 are formed on opposite sides of the bore 16 as V-shaped notches during the forming of the powder metal preform and closed to become slits when the preform is forged.
  • a crack propagates through the legs on each side of the bore 16, one crack starting at the stress riser 18 and working outwardly and the other crack starting at stress riser 20 and progressing outwardly.
  • target stress risers 22 and 24 are provided.
  • the stress risers 22 and 24 are V-shaped notches parallel to the corresponding notches 18 and 20 and opposite therefrom in the preform, and are compressed down to slits by forging.
  • the crack propagates outwardly from the stress riser 18 to the stress riser 22 and on the opposite side from the stress riser 20 to the stress riser 24 to create mating faces that are generally parallel to the initiating and target stress risers where those mating faces start and stop.
  • the provision of the target stress risers 22 and 24 also makes less likely breakout of any chips from the front and rear faces of the connecting rod where the cracks terminate.
  • the connecting rod preform 10 is essentially the same as in Fig. 1 except that the target stress risers 22' and 24' are formed as slots with a bottom radius in the preform, rather than as V-shaped notches.
  • the stress risers 22' and 24' can extend deeper into the front and rear sides of the connecting rod 10 in Fig. 2 and tend to close close less than the V-shaped notches during forging and so decrease the surface area of the mating faces that must be fractured.
  • Figs. 1 and 2 In both Figs. 1 and 2, and in all embodiments in which stress riser notches or slots are provided that are pressed closed to form a slit during forging, it is desirable to ensure that the faces of the slots or notches do not weld or join with each other during the forging operation. To this end, it is known to purposely oxidize these surfaces to hinder joinder of them during the forging operation. To further ensure against joinder during forging, the stress riser surfaces can be coated locally with graphite, or the whole connecting rod can be coated with graphite or some other weld inhibiting substance including the notch surfaces.
  • the preforms 10 can be made, for example, by powder metallurgy.
  • a connecting rod 10 has initiating stress risers 18 and 20 and in the zones 30 and 32 of desired crack propagation, the connecting rod 10 is more brittle than in the surrounding areas of the connecting rod 10 to either side of the zones 30 or 32.
  • the zones 30 and 32 can be made more brittle either by using a more brittle powder metal material in those zones when compacting the preform or by using the same material but compressing it to a lower density in the zones 30 and 32. Either way, the cracks that are initiated at the stress risers 18 and 20 are more likely to stay within the boundaries of the respective zones 30 and 32 than to wander outside those boundaries into the more ductile material that borders them.
  • the initiating stress risers 18' and 20' are significantly deeper than in the prior embodiments, and extend so deep as to intersect the bolt holes 36 and 38 that are for the bolts that fasten the bearing cap 14 to the rod portion 12 after the two parts are split. Thereby, the crack that is initiated at either of the stress risers 18' or 20' is initiated on opposite sides of the adjacent hole 36 or 38 and so is more likely to proceed around the holes in the desired fracture plane and less likely to deviate from the intended path of propagation.
  • the connecting rod 10 has initiating stress risers 18 and 20 as in the embodiments of Figs. 1-3, but on the front and rear faces of the connecting rod 10, has areas 40 and 42 of intended crack termination.
  • the area 42 is defined between two areas 44 and 46 of increased surface density, which would repel the crack from approaching them and therefore repel the crack toward the zone 42.
  • Corresponding areas 48 and 50 on the rear face of the connecting rod 10 of increased surface density border the zone 40.
  • the areas 44, 46, 48, and 50 of increased surface density may be made of higher surface density, for example, by needle peening.
  • stress risers are provided for 360° around the legs of the bearing cap 14 and rod portion 12, at the plane of intended fracture.
  • These 360° notches 54 and 56 may be smaller or more shallow than the notches 18 and 20, 22 and 24, or 22' and 24' as they go all the way around the legs.
  • they could be formed more like the slots 22' and 24', rather than V-shaped notches. They should not, however, be made so small that during forging the faces of the notches are joined to one another. Providing stress risers all the way around the legs makes it more likely that the mating faces once separated will be in or close to the same plane as the stress risers.

Landscapes

  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Manufacturing & Machinery (AREA)
  • Forging (AREA)
  • Shafts, Cranks, Connecting Bars, And Related Bearings (AREA)

Abstract

Une préforme de pièce de machine présente des caractéristiques qui permettent d'orienter la propagation d'une fissure selon une direction désirée lorsque la pièce est fractionnée après une opération de forgeage. Lesdites caractéristiques comprennent une colonne de contrainte cible qui peut se présenter sous la forme d'une entaille en V ou d'une fente, une zone de fragilité, une colonne de contrainte qui coupe un orifice de passage du boulon, des zones ayant une densité de surface plus importante et une entaille ou une fente les entourant.
PCT/US2007/008490 2006-04-13 2007-04-04 Améliorations apportées à des pièces de machine soumises à un fractionnement WO2007120564A2 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US74479706P 2006-04-13 2006-04-13
US60/744,797 2006-04-13

Publications (2)

Publication Number Publication Date
WO2007120564A2 true WO2007120564A2 (fr) 2007-10-25
WO2007120564A3 WO2007120564A3 (fr) 2008-09-25

Family

ID=38610096

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US2007/008490 WO2007120564A2 (fr) 2006-04-13 2007-04-04 Améliorations apportées à des pièces de machine soumises à un fractionnement

Country Status (1)

Country Link
WO (1) WO2007120564A2 (fr)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20150108195A1 (en) * 2012-03-12 2015-04-23 Mauser-Werke Oberndorf Maschinenbau Gmbh Method and Device for the Fracture Separation of a Workpiece
CN106736318A (zh) * 2016-11-30 2017-05-31 吉林省牧巍电子设备制造有限公司 一种发动机连杆涨断加工方法

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106826148B (zh) * 2017-01-10 2019-01-08 西安交通大学 剖分式连杆裂解的五星柱塞加载与低周疲劳裂解设备

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5105538A (en) * 1991-04-01 1992-04-21 Ford Motor Company Low-cost method of making cracked connecting rods comprised of forged wrought steel
US5551782A (en) * 1993-02-08 1996-09-03 Sintermetallwerk Krebsoge Gmbh Component having at least one split bearing seat and method of producing same
US5568891A (en) * 1988-05-17 1996-10-29 Hoag; Peter Y. Making a fractured powder metal connecting rod
US5594187A (en) * 1996-04-02 1997-01-14 Chrysler Corporation Forged powder metal connecting rod with stress riser crease formed in side thrust face
US5878491A (en) * 1996-03-29 1999-03-09 Ascoforge Safe Process for the manufacture of a forged connecting rod
US20020148325A1 (en) * 2001-04-13 2002-10-17 Bergsma S. Craig Semi-solid formed, low elongation aluminum alloy connecting rod
US20040250652A1 (en) * 2003-06-10 2004-12-16 Masaki Amano Fractured powder metal connecting rod and a method of manufacturing the same
US6961997B2 (en) * 2002-07-16 2005-11-08 Yamaha Hatsudoki Kabushiki Kaisha Fracture split method for connecting rod

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5568891A (en) * 1988-05-17 1996-10-29 Hoag; Peter Y. Making a fractured powder metal connecting rod
US5105538A (en) * 1991-04-01 1992-04-21 Ford Motor Company Low-cost method of making cracked connecting rods comprised of forged wrought steel
US5551782A (en) * 1993-02-08 1996-09-03 Sintermetallwerk Krebsoge Gmbh Component having at least one split bearing seat and method of producing same
US5878491A (en) * 1996-03-29 1999-03-09 Ascoforge Safe Process for the manufacture of a forged connecting rod
US5594187A (en) * 1996-04-02 1997-01-14 Chrysler Corporation Forged powder metal connecting rod with stress riser crease formed in side thrust face
US20020148325A1 (en) * 2001-04-13 2002-10-17 Bergsma S. Craig Semi-solid formed, low elongation aluminum alloy connecting rod
US6961997B2 (en) * 2002-07-16 2005-11-08 Yamaha Hatsudoki Kabushiki Kaisha Fracture split method for connecting rod
US20040250652A1 (en) * 2003-06-10 2004-12-16 Masaki Amano Fractured powder metal connecting rod and a method of manufacturing the same

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20150108195A1 (en) * 2012-03-12 2015-04-23 Mauser-Werke Oberndorf Maschinenbau Gmbh Method and Device for the Fracture Separation of a Workpiece
CN106736318A (zh) * 2016-11-30 2017-05-31 吉林省牧巍电子设备制造有限公司 一种发动机连杆涨断加工方法

Also Published As

Publication number Publication date
WO2007120564A3 (fr) 2008-09-25

Similar Documents

Publication Publication Date Title
US9248503B2 (en) Powder metal forging and method and apparatus of manufacture
EP2844424B1 (fr) Procédé de fabrication d'un piston pour un moteur à combustion interne
KR102057731B1 (ko) 셀프 피어싱 리벳을 이용한 접합부의 형성 방법
KR20160135713A (ko) 커넥터 및 이를 이용하는 방법
US5775817A (en) Fracture process with bore distortion controls
EP2524750A2 (fr) Procédé de fabrication de composants métalliques avec une aperture
EP2424709B1 (fr) Procédé de fabrication d'un piston pour un moteur à combustion interne
US5613182A (en) Method of manufacturing a powder metal connecting rod with stress riser crease formed in the side face
DE102012200420A1 (de) Verbindungsverfahren und verbindungswerkzeug
EP1790462A1 (fr) Procédé pour connecter un boulon à une pièce en matière plastique
WO2007120564A2 (fr) Améliorations apportées à des pièces de machine soumises à un fractionnement
EP1292423B1 (fr) Procede de production d'une came d'un arbre a cames
WO2013135652A1 (fr) Procédé et dispositif de division d'une pièce par rupture
CN100373061C (zh) 拼合式连杆
KR20140027046A (ko) 내연기관용 피스톤 및 이를 제조하기 위한 방법
EP2173515B1 (fr) Procede d'assemblage de deux composants en materiau metallique avec consolidation et traitement thermique d'au moins une partie d'au moins un composant avant l'assemblage
TW200424448A (en) Split type connecting rod
WO2018158092A1 (fr) Procédé de fabrication d'un piston
JPH10128481A (ja) コネクティングロッドの製造方法
DE102004028316A1 (de) Vorrichtung und Verfahren zum Bruchtrennen von Werkstücken
US5594187A (en) Forged powder metal connecting rod with stress riser crease formed in side thrust face
DE102006050292B4 (de) Verfahren zur Randschichtverfestigung einer Bohrung in einem metallischen Werkstück
WO2007110036A1 (fr) Procédé pour relier des éléments de construction métalliques et composant ainsi fabriqué
EP1589238B1 (fr) Méthode de production d'un composant avec un dispositif de palier séparable par fracture
DE102004046100A1 (de) Verfahren zum Fügen zweier Werkstücke und nach dem Verfahren hergestelltes gefügtes Bauteil

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 07754926

Country of ref document: EP

Kind code of ref document: A2

NENP Non-entry into the national phase in:

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 07754926

Country of ref document: EP

Kind code of ref document: A2