EP0430362A1 - Pistons - Google Patents

Pistons Download PDF

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Publication number
EP0430362A1
EP0430362A1 EP90203101A EP90203101A EP0430362A1 EP 0430362 A1 EP0430362 A1 EP 0430362A1 EP 90203101 A EP90203101 A EP 90203101A EP 90203101 A EP90203101 A EP 90203101A EP 0430362 A1 EP0430362 A1 EP 0430362A1
Authority
EP
European Patent Office
Prior art keywords
skirt
piston
gudgeon pin
wall members
pin bosses
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Withdrawn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
EP90203101A
Other languages
German (de)
English (en)
Inventor
David Riding
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.)
Federal Mogul Bradford Ltd
Original Assignee
AE Piston Products Ltd
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 AE Piston Products Ltd filed Critical AE Piston Products Ltd
Publication of EP0430362A1 publication Critical patent/EP0430362A1/fr
Withdrawn legal-status Critical Current

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02F—CYLINDERS, PISTONS OR CASINGS, FOR COMBUSTION ENGINES; ARRANGEMENTS OF SEALINGS IN COMBUSTION ENGINES
    • F02F3/00—Pistons 
    • F02F3/02—Pistons  having means for accommodating or controlling heat expansion
    • F02F3/022—Pistons  having means for accommodating or controlling heat expansion the pistons having an oval circumference or non-cylindrical shaped skirts, e.g. oval
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02F—CYLINDERS, PISTONS OR CASINGS, FOR COMBUSTION ENGINES; ARRANGEMENTS OF SEALINGS IN COMBUSTION ENGINES
    • F02F2200/00—Manufacturing
    • F02F2200/06—Casting

Definitions

  • the present invention relates to pistons for internal combustion engines and compressors.
  • the skirts of pistons for internal combustion engines and compressors have generally been of either a substantially cylindrical form when viewed from the open end or have appeared to comprise two circular arcs, constituting the piston thrust faces, joined at their circumferential ends by generally planar panels extending normally to the wrist pin axis. This statement ignores the fact that the piston thrust faces are machined to a slightly oval curvature, the degree of which is not normally visible to the naked eye.
  • the fully cylindrical skirt suffers from the disadvantage of being relatively heavy; it being highly desirable to reduce reciprocating mass in an engine.
  • the second type of conventional piston having generally planar panels between the thrust faces and known in the art as a "slipper" piston, whilst being lighter than the cylindrical piston, has other disadvantages. These disadvantages lie in the fact that there is a high stress concentration at the junction between the thrust face arcs and the planar panels and there is a steep, skirt stiffness gradient from the centre of the thrust faces to the thrust face/panel junction.
  • a further disadvantage in some engine designs which may be prone to detonation or have bores prone to distortion from true cylindrical form due to siamesing, for example, is that a high ovality piston is intolerant; the higher loads due to detonation or distortion cause even more skirt deformation which again leads to scuffing, notwithstanding the high ovality, and consequently greater noise due to piston slap.
  • a piston including a crown portion, gudgeon pin bosses and a skirt portion, the skirt portion comprising thrust faces which are joined at their outer extremities by curved skirt wall members which include the gudgeon pin bosses characterised in that when viewed along the piston axis towards the open, lower-end of the skirt portion, the skirt wall members present an oval form, at least from the lower external surface of the gudgeon pin bosses to the open lower extremity of the skirt.
  • the oval form of the skirt wall members may extend over substantially all of the axial length of the skirt below the crown, the crown being considered to also include all of the piston ring grooves, or over any intermediate length of skirt.
  • stiffening belt In gravity cast pistons there is generally a feature known as a "stiffening belt" which is a radially thickened portion of the skirt occuring at an axial level around the lower region of the gudgeon pin bosses and generally extending around a major proportion of the skirt periphery.
  • Some pistons have a gap in the stiffening belt, generally coinciding with the circumferential centres of the thrust faces.
  • the oval open end shape lies at or about the axial level of the stiffening belt and axially below.
  • the oval appearance of the skirt open end may be formed by the skirt wall members comprising arcs of circles having centres of curvature offset from the piston axis.
  • Figure 1 shows a composite view of open ends of prior art pistons; the left-hand side being of a conventional, substantially cylindrical piston and the right-hand side of a conventional "slipper" type piston;
  • Figure 2 shows the open end of a piston according to the present invention
  • Figure 3 shows a section through the plane including the piston axis and the normal to the gudgeon pin axis of the piston of Figure 2;
  • Figure 4 shows a section taken at the level of the gudgeon pin axis of a second embodiment of a piston according to the present invention.
  • Figure 5 which shows the piston of Figure 4 when viewed along the piston axis towards the open end.
  • the piston skirt 10 is of substantially circular construction and has a stiffening belt 12 disposed around the inner peripheral wall 14 of the skirt 12.
  • the stiffening belt 12 is thickest at a plane containing both the piston axis 16 and gudgeon pin axis 18.
  • the stiffening belt is present to control the stiffness gradient at the lower skirt end and lies adjacent the lower extremity of the gudgeon pin bosses 20.
  • the slipper type piston shown on the right-hand side of Figure 1 is lighter in weight than a cylindrical piston due to the reduced quantity of metal needed in construction.
  • the piston has thrust faces 30, 32 linked at their outer extremities 34, 36 by generally planar skirt wall panels 38.
  • the stiffness gradient from the centre 40 of the thrust faces to the outer extremities 34, 36 is very high, leading to scuffing in these outer regions.
  • the piston shown in Figures 2 and 3 has an oval shaped open end as defined by the skirt wall members 50, 52.
  • a stiffening belt 54 of thicker material is included at a level adjacent the lower extremity 56 of the gudgeon pin boss 58.
  • the oval shape comprises the arcs of circles having centres 60, 62 displaced from the piston axis 64.
  • the walls 50, 52 join the outer extremities 66, 68 of the thrust faces 70, 72.
  • the oval shape extends from the stiffening belt 54 to the lowest extremities of the piston; above the belt 54 , in the region of the gudgeon pin bosses the walls 50 become waisted as indicated by the dashed lines 74.
  • Figures 4 and 5 show a piston having an oval open end, which oval section is continued along substantially the whole of the axial length of the skirt.
  • Figure 4 is a section taken through the gudgeon pin axis 80.
  • the thrust faces 82 are joined by curved walls 84 which also include gudgeon pin bosses 86.
  • a stiffening belt 88 is also included, but which has a gap 90 at the centre of the skirt about the plane including both the piston axis 92 and the normal to the gudgeon pin axis 80.
  • the walls joining the thrust face extremities have been formed from arcs of circles having their centres offset from the piston axis, the walls may be of non circular form.

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Pistons, Piston Rings, And Cylinders (AREA)
EP90203101A 1989-11-30 1990-11-22 Pistons Withdrawn EP0430362A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB898927125A GB8927125D0 (en) 1989-11-30 1989-11-30 Pistons
GB8927125 1989-11-30

Publications (1)

Publication Number Publication Date
EP0430362A1 true EP0430362A1 (fr) 1991-06-05

Family

ID=10667229

Family Applications (1)

Application Number Title Priority Date Filing Date
EP90203101A Withdrawn EP0430362A1 (fr) 1989-11-30 1990-11-22 Pistons

Country Status (2)

Country Link
EP (1) EP0430362A1 (fr)
GB (2) GB8927125D0 (fr)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE4109160A1 (de) * 1991-03-20 1992-09-24 Alcan Gmbh Kolben fuer brennkraftmaschinen
WO2009006978A1 (fr) * 2007-07-06 2009-01-15 Ks Kolbenschmidt Gmbh Piston pour moteur à combustion interne, présentant des parois à obliquité accrue
CN103233828A (zh) * 2013-04-28 2013-08-07 石家庄金刚凯源动力科技有限公司 用于潍柴wp10系列柴油机的活塞
EP2663760A1 (fr) * 2011-01-13 2013-11-20 Federal-Mogul Nürnberg GmbH Piston à utiliser dans des moteurs à combustion interne
US20180372020A1 (en) * 2013-10-14 2018-12-27 Ks Kolbenschmidt Gmbh Piston For An Internal Combustion Engine and Production Method Therefore

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE4414678A1 (de) * 1994-04-27 1995-11-02 Mahle Gmbh Leichtmetallkolben für Verbrennungsmotoren
US5476076A (en) * 1994-12-06 1995-12-19 Zhou; Zhishan Internal combustion piston engine utilizing interference movable fit technology
DE19643778C2 (de) * 1996-10-23 2000-04-13 Alcan Gmbh Leichtbaukolben
EP1348859B2 (fr) 2002-03-25 2010-04-07 BRP-Powertrain GmbH & Co. KG Piston

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CH225228A (de) * 1939-04-20 1943-01-15 Schmidt Gmbh Karl Kolben für Brennkraftmaschinen.
GB1002060A (en) * 1963-08-03 1965-08-25 Schmidt Gmbh Karl A piston for internal combustion engines and the like
DE1475846A1 (de) * 1965-01-12 1969-06-12 Schmidt Gmbh Karl Kolben,insbesondere fuer Verbrennungskraftmaschinen
WO1988007132A1 (fr) * 1982-11-15 1988-09-22 Kievsky Avtomobilno-Dorozhny Institut Imeni 60-Let Piston de moteur a combustion interne

Family Cites Families (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR481347A (fr) * 1915-04-12 1916-11-22 William Yeates Perfectionnements apportés aux serrures de portes
GB245063A (en) * 1924-12-26 1926-05-06 Marc Birkigt Improvements in or relating to pistons for internal combustion engines
GB404273A (en) * 1932-06-09 1934-01-09 William Arthur Oubridge Improvements in pistons
GB414390A (en) * 1933-01-28 1934-07-30 Aluminium Ltd Improvements in or relating to pistons
GB456792A (en) * 1935-01-21 1936-11-16 Aluminium Ltd Improvements in or relating to pistons
GB549159A (en) * 1941-07-14 1942-11-09 Thompson Prod Inc Improvements in or relating to pistons
GB1261020A (en) * 1968-03-29 1972-01-19 Ass Eng Ltd Pistons
JPS6181558A (ja) * 1984-09-27 1986-04-25 Honda Motor Co Ltd 内燃機関用ピストン

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CH225228A (de) * 1939-04-20 1943-01-15 Schmidt Gmbh Karl Kolben für Brennkraftmaschinen.
GB1002060A (en) * 1963-08-03 1965-08-25 Schmidt Gmbh Karl A piston for internal combustion engines and the like
DE1475846A1 (de) * 1965-01-12 1969-06-12 Schmidt Gmbh Karl Kolben,insbesondere fuer Verbrennungskraftmaschinen
WO1988007132A1 (fr) * 1982-11-15 1988-09-22 Kievsky Avtomobilno-Dorozhny Institut Imeni 60-Let Piston de moteur a combustion interne

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE4109160A1 (de) * 1991-03-20 1992-09-24 Alcan Gmbh Kolben fuer brennkraftmaschinen
DE4109160C2 (fr) * 1991-03-20 1993-06-17 Alcan Deutschland Gmbh, 3400 Goettingen, De
EP0563408A1 (fr) * 1991-03-20 1993-10-06 Alcan Deutschland Gmbh Piston pour un moteur à combustion interne
US5299490A (en) * 1991-03-20 1994-04-05 Alcan Deutschland Gmbh Piston with flush connecting wall sections at pin boss surface
DE4109160C3 (de) * 1991-03-20 2000-11-30 Federal Mogul Nuernberg Gmbh Kolben für Brennkraftmaschinen
US8387585B2 (en) 2007-07-06 2013-03-05 Ks Kolbenschmidt Gmbh Piston of an internal combustion engine with an increased inclination of the box walls of the piston
WO2009006978A1 (fr) * 2007-07-06 2009-01-15 Ks Kolbenschmidt Gmbh Piston pour moteur à combustion interne, présentant des parois à obliquité accrue
EP2663760A1 (fr) * 2011-01-13 2013-11-20 Federal-Mogul Nürnberg GmbH Piston à utiliser dans des moteurs à combustion interne
CN103443432A (zh) * 2011-01-13 2013-12-11 菲特尔莫古纽伦堡有限公司 用于内燃机的活塞
US8955488B2 (en) 2011-01-13 2015-02-17 Federal-Mogul Nurnberg Gmbh Piston for use in internal combustion engines
CN103233828A (zh) * 2013-04-28 2013-08-07 石家庄金刚凯源动力科技有限公司 用于潍柴wp10系列柴油机的活塞
CN103233828B (zh) * 2013-04-28 2015-06-03 石家庄金刚凯源动力科技有限公司 用于潍柴wp10系列柴油机的活塞
US20180372020A1 (en) * 2013-10-14 2018-12-27 Ks Kolbenschmidt Gmbh Piston For An Internal Combustion Engine and Production Method Therefore

Also Published As

Publication number Publication date
GB9025495D0 (en) 1991-01-09
GB8927125D0 (en) 1990-01-31
GB2238596A (en) 1991-06-05

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