WO1995019493A1 - Mecanisme de distribution a programme variable - Google Patents

Mecanisme de distribution a programme variable Download PDF

Info

Publication number
WO1995019493A1
WO1995019493A1 PCT/GB1994/002797 GB9402797W WO9519493A1 WO 1995019493 A1 WO1995019493 A1 WO 1995019493A1 GB 9402797 W GB9402797 W GB 9402797W WO 9519493 A1 WO9519493 A1 WO 9519493A1
Authority
WO
WIPO (PCT)
Prior art keywords
drive
drive mechanism
camshaft
lever
contact
Prior art date
Application number
PCT/GB1994/002797
Other languages
English (en)
Inventor
Thomas Tsoi Hei Ma
Original Assignee
Ford Motor Company Limited
Ford Werke Ag
Ford France S.A.
Ford Motor Company
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 Ford Motor Company Limited, Ford Werke Ag, Ford France S.A., Ford Motor Company filed Critical Ford Motor Company Limited
Priority to DE69411193T priority Critical patent/DE69411193T2/de
Priority to EP95905179A priority patent/EP0739444B1/fr
Publication of WO1995019493A1 publication Critical patent/WO1995019493A1/fr

Links

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01L—CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
    • F01L13/00—Modifications of valve-gear to facilitate reversing, braking, starting, changing compression ratio, or other specific operations
    • F01L13/0015—Modifications of valve-gear to facilitate reversing, braking, starting, changing compression ratio, or other specific operations for optimising engine performances by modifying valve lift according to various working parameters, e.g. rotational speed, load, torque
    • F01L13/0057—Modifications of valve-gear to facilitate reversing, braking, starting, changing compression ratio, or other specific operations for optimising engine performances by modifying valve lift according to various working parameters, e.g. rotational speed, load, torque by splittable or deformable cams

Definitions

  • the present invention relates to a variable valve timing mechanism for an internal combustion engine.
  • the present invention seeks to provide a variable valve timing mechanism which introduces lost motion into the valve train but which mitigates noise nd wear problems.
  • a drive mechanism for transmitting driving torque from the crankshaft to a camshaft of an internal combustion engine and incorporating means for permitting a limited degree of rotation of one of the shafts relative to the other
  • the drive mechanism comprising concentric drive and driven members connectible respectively to the crankshaft and the camshaft, and a lever pivotably supported on one of the members and having a force transmitting surface that is biassed by a spring to remain in contact at all times with a reaction surface on the other member, the position of the point of contact between the two surfaces being dependent upon the relative angular position of the drive and driven members and being operative to move progressively to vary the mechanical advantage of the lever as the shafts rotate relative to one another under the action of the torque reversals on the camshaft.
  • the spring does not act directly between the drive and driven members but does so through a variable ratio lever.
  • direct drive conditions when all the lost motion is taken up
  • the point of contact between the drive surface of the lever and the reaction surface on the other member is nearly coincident with the pivot point of the lever, resulting in the effective lever arms having a very large ratio and increasing the drive torque transmitted.
  • the torque on the camshaft is reversed by a valve spring acting on a cam
  • the point of contact moves away from the pivot point of the lever, first reducing the transmitted torque and then allowing the reverse torque to accelerate the camshaft and make it lead the crankshaft within the permissible limited lost motion.
  • the surface of the lever and the reaction surface with which it makes contact are profiled in such a manner that the surface of the lever rolls without slipping on the reaction surface. This avoids wear due to friction and reduces the lubrication requirements of the mechanism.
  • the strength of the valve springs and the friction on the valve train determine the applied torque to effect the phase change and the rate of change of the phase during such torque reversal will also depend upon the moment of inertia of the drive mechanism.
  • the amplitude of the phase change i.e. the extent to which the duration of the valve event is reduced, further depends on the time that the torque acts, in other words upon the engine speed.
  • the valve springs and the moment of inertia are constant and the extent of variation will vary only and automatically with engine speed, assuming no change in friction. It is possible to apply a variable drag between the drive and driven members, for example by the use of a magnetic clutch, to reduce the phase change occurring at any given engine speed.
  • Figure 1 is a transverse section through a drive mechanism, taken along the section line I-I in Figure 2, and
  • Figure 2 is an axial section through the drive mechanism, taken along the section line II-II in Figure 1.
  • a drive mechanism comprises a driven member 10 connected to the camshaft 12 of an engine, and a drive member 14 driven through a belt 16 by the engine crankshaft.
  • the drive member 14 is journalled about the camshaft 12 and can rotate relative to it.
  • the coupling between the drive and driven members 14 and 10 is effected by means of pins 18 in the driven member 10 about which there are pivoted two levers 20 that are both biassed to rotate in a clockwise direction as viewed in Figure 1 by helical springs 22.
  • the pins 18 and levers 20 are located within a deep recess in the drive member 14 bounded by reaction surfaces 24 against which the levers 20 are urged by the springs 22.
  • An electromagnetic clutch 30 is included to apply a controllable drag between the drive and driven members 14 and 10.
  • a disk 32 is formed in close proximity to the drive member 14 and fixed for rotation with the camshaft 12 and an electromagnet 34 powered by a suitable control circuit 36 can apply a variable magnetic field to a thin film of magnetic fluid 38 disposed between the disk 32 and the drive member 14.
  • the purpose of the clutch 30 is to apply a variable drag between the drive and driven members 14 and 10 to moderate the extent of phase change at any given engine speed.
  • the illustrated embodiment incorporates a position sensor 40 that provides a position feedback signal to the control circuit 36 so that the phase change can be accurately closed loop controlled.
  • both surface may ⁇ be curved or the reaction surfaces alone may be curved.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Valve Device For Special Equipments (AREA)
  • Valve-Gear Or Valve Arrangements (AREA)

Abstract

L'invention se rapporte à un mécanisme d'entraînement destiné à transmettre le couple d'entraînement du vilebrequin à l'arbre à cames d'un moteur à combustion interne. Ce mécanisme comprend des moyens permettant un degré limité de rotation de l'un des arbres par rapport à l'autre, ainsi que des éléments d'entraînement et des éléments entraînés (14, 10) concentriques, reliés respectivement au vilebrequin et à l'arbre à cames. Au moins un levier (20) est supporté pivotant sur l'un des membres (10) et présente une surface de transmission de force qui est sollicitée par un ressort (22) afin de rester sans cesse en contact avec une surface de réaction (24) sur l'autre élément. La position du point de contact entre les deux surfaces dépend de la position relative angulaire des éléments d'entraînement et des éléments entraînés (14, 10) et elle se déplace progressivement afin de faire varier le rapport de multiplication du levier au moment où les arbres tournent l'un par rapport à l'autre sous l'action des renversements de couple sur l'arbre à cames (12).
PCT/GB1994/002797 1994-01-15 1994-12-15 Mecanisme de distribution a programme variable WO1995019493A1 (fr)

Priority Applications (2)

Application Number Priority Date Filing Date Title
DE69411193T DE69411193T2 (de) 1994-01-15 1994-12-15 Variable ventilsteuervorrichtung
EP95905179A EP0739444B1 (fr) 1994-01-15 1994-12-15 Mecanisme de distribution a programme variable

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB9400748.1 1994-01-15
GB9400748A GB2285671A (en) 1994-01-15 1994-01-15 Variable valve timing mechanism

Publications (1)

Publication Number Publication Date
WO1995019493A1 true WO1995019493A1 (fr) 1995-07-20

Family

ID=10748875

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/GB1994/002797 WO1995019493A1 (fr) 1994-01-15 1994-12-15 Mecanisme de distribution a programme variable

Country Status (4)

Country Link
EP (1) EP0739444B1 (fr)
DE (1) DE69411193T2 (fr)
GB (1) GB2285671A (fr)
WO (1) WO1995019493A1 (fr)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102005024485A1 (de) * 2005-05-27 2006-11-30 Daimlerchrysler Ag Nockenwelleneinheit

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3234640A1 (de) * 1982-09-18 1984-03-22 Volkswagenwerk Ag, 3180 Wolfsburg Ventiltrieb, insbesondere fuer eine brennkraftmaschine
DE4026480A1 (de) * 1989-08-31 1991-03-07 Volkswagen Ag Nockenwellenanordnung, insbesondere fuer ladungswechselventile einer brennkraftmaschine, mit zumindest einem schwenknocken

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB884434A (en) * 1958-11-29 1961-12-13 Bosch Gmbh Robert Improvements in or relating to hydraulically adjustable rotary couplings
GB2247935A (en) * 1990-09-12 1992-03-18 Ford Motor Co Camshaft drive mechanism

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3234640A1 (de) * 1982-09-18 1984-03-22 Volkswagenwerk Ag, 3180 Wolfsburg Ventiltrieb, insbesondere fuer eine brennkraftmaschine
DE4026480A1 (de) * 1989-08-31 1991-03-07 Volkswagen Ag Nockenwellenanordnung, insbesondere fuer ladungswechselventile einer brennkraftmaschine, mit zumindest einem schwenknocken

Also Published As

Publication number Publication date
EP0739444A1 (fr) 1996-10-30
GB9400748D0 (en) 1994-03-16
DE69411193T2 (de) 1999-03-11
DE69411193D1 (de) 1998-07-23
EP0739444B1 (fr) 1998-06-17
GB2285671A (en) 1995-07-19

Similar Documents

Publication Publication Date Title
AU2023202225B2 (en) Nut and lead screw type opening and closing mechanism for automatic door, automatic vehicle door, and vehicle
KR100253609B1 (ko) 가변동 밸브 기구
US5161493A (en) Phase change mechanism
US4273307A (en) Clutch for valve actuator
WO1992000441A1 (fr) Mecanisme de changement de phase
US4302985A (en) Phase controlling system for two rotatable shafts
US7207300B2 (en) Variable valve mechanism
US6250267B1 (en) Rolling element phaser
EP0067311A1 (fr) Dispositif de distribution variable des soupapes pour un moteur à combustion interne
EP0739444B1 (fr) Mecanisme de distribution a programme variable
US5601056A (en) Device for actuating the valves in internal combustion engines by means of revolving cams
JPH09506404A (ja) 可変自在な弁の調時
CN112539093A (zh) 一种用于内燃机的气门正时和升程可变装置及其调节方式
EP0548170B1 (fr) Moteur a combustion interne a phases de distribution variables
US5518092A (en) Phase change mechanism
EP0463023B1 (fr) Mecanisme de changement de phase
SU1034614A3 (ru) Устройство дл регулировани изменени угла опережени впрыска в зависимости от скорости вращени двух соосно расположенных валов двигател внутреннего сгорани
WO1984003331A1 (fr) Mecanisme de soupape
JPS59131715A (ja) エンジンカムシヤフト駆動機構
EP0656094B1 (fr) Mecanisme de changement de phase
JPH11173120A (ja) 内燃機関の可変動弁装置
CA1321515C (fr) Appareil regulateur d'injection
JPH07116927B2 (ja) エンジンの動弁装置
JP4001693B2 (ja) 内燃機関の可変動弁装置
JP2001263014A (ja) 内燃機関の可変動弁装置

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): JP US

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): AT BE CH DE DK ES FR GB GR IE IT LU MC NL PT SE

DFPE Request for preliminary examination filed prior to expiration of 19th month from priority date (pct application filed before 20040101)
121 Ep: the epo has been informed by wipo that ep was designated in this application
WWE Wipo information: entry into national phase

Ref document number: 1995905179

Country of ref document: EP

WWP Wipo information: published in national office

Ref document number: 1995905179

Country of ref document: EP

WWG Wipo information: grant in national office

Ref document number: 1995905179

Country of ref document: EP