EP1985816A1 - System for continuously varying the lift and the phase of the valves in an internal combustion engine - Google Patents

System for continuously varying the lift and the phase of the valves in an internal combustion engine Download PDF

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Publication number
EP1985816A1
EP1985816A1 EP08152053A EP08152053A EP1985816A1 EP 1985816 A1 EP1985816 A1 EP 1985816A1 EP 08152053 A EP08152053 A EP 08152053A EP 08152053 A EP08152053 A EP 08152053A EP 1985816 A1 EP1985816 A1 EP 1985816A1
Authority
EP
European Patent Office
Prior art keywords
support
valves
camshaft
rocker arm
internal combustion
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Withdrawn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
EP08152053A
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German (de)
English (en)
French (fr)
Inventor
Giovambattista Vaccaro
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.)
Piaggio and C SpA
Original Assignee
Piaggio and C SpA
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 Piaggio and C SpA filed Critical Piaggio and C SpA
Publication of EP1985816A1 publication Critical patent/EP1985816A1/en
Withdrawn legal-status Critical Current

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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
    • F01L13/0021—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 modification of rocker arm ratio
    • 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
    • F01L13/0021—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 modification of rocker arm ratio
    • F01L13/0026—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 modification of rocker arm ratio by means of an eccentric

Definitions

  • the present invention refers to a system for continuously varying the lift and the phase of the valves in an alternating internal combustion engine.
  • cams As known, in internal combustion engines the opening and closing of the intake and discharge valves of each cylinder is commanded by special eccentrics, known as cams, normally fitted onto a so-called camshaft.
  • the camshaft is actuated by the drive shaft, with respect to which it rotates at half the angular speed and to which it is connected through a chain or a belt or else, more rarely, through a cascade of gears.
  • the shape of the eccentrics is a defining characteristic for the performance of an engine, since it has an influence both on the opening time, or phase, of each valve, and upon the excursion, expressed in millimetres, of the valve itself. Moreover, the shape of the eccentrics is also a defining characteristic for the noisiness of the engine, since it regulates the impact between the valves and the respective seats.
  • phase variators which indeed allow the opening time of the valves themselves to be varied.
  • the variation of the discharge phase allows the crossing over of valves, in other words the phase in which both the intake valves and the discharge valves are open simultaneously after the burning of the mixture, to be increased, so that the unburnt gases are expelled outside of the chamber thanks to the entry of the new mixture.
  • this delicate phase a small percentage of mixture is lost, but the advantage that is obtained is a good washing of the combustion chamber that thus, at each burn, is always clean and cooled as it should be.
  • valve control systems normally made separately and with different technologies, are however expensive and delicate, especially when actuated hydraulically, and therefore are only intended for use on certain high-performance vehicles.
  • the purpose of the present invention is therefore to make a system that is able to simultaneously and completely mechanically vary both the lift and the phase of the valves of an internal combustion engine.
  • Another purpose of the invention is to make a system for continuously varying the lift and the phase of the valves in an internal combustion engine that is quick and simple to adjust.
  • valves 10 and 12 which can be for intake or else discharge, have a first embodiment of the system for continuously varying the lift and phase according to the present invention applied to them.
  • Each valve 10, 12 is directly commanded by a rocker arm 14, of the so-called finger type, provided or not with a roller 16 for reducing friction.
  • the clearances of each valve 10, 12 can be controlled through a hydraulic recovery mechanism 18.
  • a capsule or tablet 20 ( figure 6 ) can possibly be arranged for adjusting the clearances.
  • Each finger rocker arm 14 is in turn commanded by the camshaft 22 through the interposition of a second rocker arm 24, or intermediate rocker arm.
  • each cam 26 actuates the relative intermediate rocker arm 24 that transmits the motion to the finger rocker arm 14 and, consequently, to the valves 10 and 12.
  • the intermediate rocker arm 24 has the special characteristic of having the contact surface 28 with the roller 16 of the finger rocker arm 14 equipped with a specific profile.
  • at least one portion 28a of such a contact surface 28 in other words the portion along which the motion for adjusting/varying the phase and the lift, has its centre of curvature coinciding with the rotation axis C of the camshaft 22, as can be seen in figure 2 .
  • a second portion 28b, possibly not present, of the contact surface 28, on the other hand, has a different centre of curvature to the centre C. What has been stated up to now is only valid should the contact between the roller 30 of the intermediate rocker arm 24 and the relative cam 26 of the camshaft 22 take place along the base circle of the cam 26 itself. Should the second portion 28b of the contact surface 28 be present, its curvature can also not be constant.
  • Each intermediate rocker arm 24 is hinged on a pin 32 supported by a support 34.
  • the support 34 is hinged on the camshaft 22, with the possibility of rotating with respect to it, and it is formed of a top part 34a and a bottom part 34b, joined together by means of a plurality of screws 36.
  • each roller 30 and the relative cam 26 is aided by the action of a spring 38 fixedly connected to each intermediate rocker arm 24.
  • a spring 38 has a fixed reaction point on the support 34 and is housed on the support 34 itself.
  • the axial check of the intermediate rocker arm 24 is thus carried out through a washer 40 and a stop ring 42 of the Seeger ® type, both applied in a position opposite that in which the spring 38 is located.
  • the angular positioning of the support 34 and, consequently, of the intermediate rocker arms 24 is carried out through a control eccentric 44 fixedly connected to a drive shaft 46 supported by the structure of the head (not shown) of the engine.
  • the camshaft 22 and the seats 48 of each valve 10, 12 are also supported, in a conventional manner, on the head.
  • the eccentric 44 is engaged by pressure with a control roller 50 hinged onto the support 34.
  • the contact between the eccentric 44 and the control roller 50 is kept constant thanks to the action of a spring 52, connected to the support 34 and having a fixed reaction point on the head of the engine or on another fixed component.
  • the correct sizing of the portions 28a and 28b of each contact surface 28, as well as of the cams 26 and the relative orientation between the pairs of command and intermediate rocker arms 14, 24, shall achieve the desired relationship between the variation in lift and the variation in phase of each valve 10, 12, and without affecting the predetermined maximum and minimum lift range.
  • Figures 7, 8 and 9 show a second example embodiment of the system for continuously varying the lift and the phase of the valves in an internal combustion engine according to the present invention.
  • the command rocker arm 14 of each valve 10, 12 lacks the hydraulic clearance recovery mechanism 18.
  • the command rocker arm 14 is thus pivoted on a pin 54, supported by the structure of the head or else by another member that is fixed with respect to the engine.
  • the adjustment of the clearances can be carried out through a suitable calibrated thickness 56 ( figure 7 ) arranged between each valve 10, 12 and the relative command rocker arm 14.
  • Figures 10, 11 and 12 show a third example embodiment of the system for continuously varying the lift and the phase of the valves in an internal combustion engine according to the present invention.
  • the angular positioning of the support 34 and of the intermediate rocker arms 24 hinged onto it takes place through a gearwheel sector 58 applied onto the support 34 itself.
  • the gearwheel sector 58 is able to operate both autonomously, and through the interposition of reducing gears.
  • figures 13 to 18 show a fourth example embodiment of the system for continuously varying the lift and the phase of the valves in an internal combustion engine according to the present invention, intended in particular for being used on racing engines.
  • the system illustrated in such figures is conceptually identical to the previous ones, but it is specifically designed to keep the mass to a bare minimum.
  • Each valve 10 and 12 is still directly commanded by the finger rocker arm 14, in turn actuated by the intermediate rocker arm 24 that receives the motion from the camshaft 22.
  • Each intermediate rocker arm 24 is thus hinged on the relative pin 32 supported by the support 34.
  • each finger rocker arm 14 is hinged, at an end thereof, on a small shaft 60 fixedly connected to the head of the engine, whereas the support 34 of the intermediate rocker arms 24 is again configured in such a way as to be able to rotate about the camshaft 22.
  • the support 34 is provided, in addition to the rotation seat on the camshaft 22, with a further circular surface portion or raceway 62 concentric to the rotation axis of the camshaft 22 itself.
  • the support 34 can thus rotate about the camshaft 22 making the raceway 62 slide on the circular portion 44a of the control eccentric 44 that, in this example embodiment, is rigidly fixed, removably or not, onto the small pivoting shaft 60 of the command rocker arms 14. Therefore, in this particular example embodiment, the small shaft 60, free to rotate in its own support seat and with respect to the rocker arms 14, also acts as a drive shaft, thus contributing to reducing the number of components and, therefore, the mass.
  • the preloading spring 52 hooked to the support 34 and connected to the structure of the head or to another fixed member, shall keep the contact between the roller 64 and the control eccentric 44 constant, thus making the adjustment of the position of the support 34 and, consequently, of the lift and phasing of the valves 10 and 12 stable.
  • each cam 26 and the relative intermediate rocker arm 24 can be adjusted by the screw system 36 of the support 34 that, in this embodiment, is formed of a single piece and stays in position because it is held by the contact with the roller 64, by the contact between the raceways 62 and the raceways 44a, and with the housing on the cam axis 22.

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)
EP08152053A 2007-03-05 2008-02-28 System for continuously varying the lift and the phase of the valves in an internal combustion engine Withdrawn EP1985816A1 (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
ITMI20070443 ITMI20070443A1 (it) 2007-03-05 2007-03-05 Sistema per la variazione continua dell'alzata e della fase delle valvole in un motore a combustione interna

Publications (1)

Publication Number Publication Date
EP1985816A1 true EP1985816A1 (en) 2008-10-29

Family

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Family Applications (1)

Application Number Title Priority Date Filing Date
EP08152053A Withdrawn EP1985816A1 (en) 2007-03-05 2008-02-28 System for continuously varying the lift and the phase of the valves in an internal combustion engine

Country Status (4)

Country Link
EP (1) EP1985816A1 (zh)
CN (1) CN101260818A (zh)
IT (1) ITMI20070443A1 (zh)
TW (1) TW200905062A (zh)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR101090793B1 (ko) 2008-03-26 2011-12-08 현대자동차주식회사 연소기관의 밸브 어셈블리의 밸브 개폐 및 밸브 행정 조정장치
CN103758598B (zh) * 2013-12-30 2016-05-11 长城汽车股份有限公司 用于发动机的配气机构及具有其的车辆

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102010048708A1 (de) * 2010-10-19 2012-04-19 Kolbenschmidt Pierburg Innovations Gmbh Mechanisch steuerbarer Ventiltrieb
CN102678219A (zh) * 2011-03-08 2012-09-19 朱譞晟 可变平面支撑体全可变气门正时和升程机构
CN103925030B (zh) * 2013-01-15 2018-01-09 长城汽车股份有限公司 一种可变气门升程驱动装置
CN103925033B (zh) * 2013-01-15 2017-02-08 长城汽车股份有限公司 摆臂调节架
WO2014110968A1 (zh) * 2013-01-15 2014-07-24 长城汽车股份有限公司 一种可变气门升程驱动装置
CN111219223A (zh) * 2018-11-26 2020-06-02 博格华纳公司 电致动可变凸轮轴正时设备控制器

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB337291A (en) * 1929-01-15 1930-10-30 Motorenfabrik Deutz Ag Improvements in and relating to the regulation of internal combustion engines
EP0717174A1 (en) * 1994-12-12 1996-06-19 Isuzu Motors Limited Valve operating system for internal combustion engine
DE19960742A1 (de) * 1999-12-16 2001-06-21 Iav Gmbh Variabler Ventiltrieb, vorzugsweise für Verbrennungsmotoren
WO2003095805A1 (de) * 2002-05-13 2003-11-20 Thyssenkrupp Automotive Ag Antriebs und verstellsystem für variable ventilsteuerungen
EP1426570A2 (en) * 2000-06-30 2004-06-09 Delphi Technologies, Inc. Low friction variable valve actuation device
US20050241598A1 (en) * 2004-04-28 2005-11-03 Toyota Jidosha Kabushiki Kaisha Variable valve mechanism
DE102005053250A1 (de) * 2004-11-30 2006-06-01 Hitachi, Ltd. Betätigungseinrichtung für im Betrieb verstellbare Ventile für Brennkraftmaschinen

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB337291A (en) * 1929-01-15 1930-10-30 Motorenfabrik Deutz Ag Improvements in and relating to the regulation of internal combustion engines
EP0717174A1 (en) * 1994-12-12 1996-06-19 Isuzu Motors Limited Valve operating system for internal combustion engine
DE19960742A1 (de) * 1999-12-16 2001-06-21 Iav Gmbh Variabler Ventiltrieb, vorzugsweise für Verbrennungsmotoren
EP1426570A2 (en) * 2000-06-30 2004-06-09 Delphi Technologies, Inc. Low friction variable valve actuation device
WO2003095805A1 (de) * 2002-05-13 2003-11-20 Thyssenkrupp Automotive Ag Antriebs und verstellsystem für variable ventilsteuerungen
US20050241598A1 (en) * 2004-04-28 2005-11-03 Toyota Jidosha Kabushiki Kaisha Variable valve mechanism
DE102005053250A1 (de) * 2004-11-30 2006-06-01 Hitachi, Ltd. Betätigungseinrichtung für im Betrieb verstellbare Ventile für Brennkraftmaschinen

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR101090793B1 (ko) 2008-03-26 2011-12-08 현대자동차주식회사 연소기관의 밸브 어셈블리의 밸브 개폐 및 밸브 행정 조정장치
CN103758598B (zh) * 2013-12-30 2016-05-11 长城汽车股份有限公司 用于发动机的配气机构及具有其的车辆

Also Published As

Publication number Publication date
CN101260818A (zh) 2008-09-10
TW200905062A (en) 2009-02-01
ITMI20070443A1 (it) 2008-09-06

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