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WO2008131992A1 - Mécanisme de distribution à cames spatiales, à géométrie de cames spatiales modifiée - Google Patents

Mécanisme de distribution à cames spatiales, à géométrie de cames spatiales modifiée Download PDF

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Publication number
WO2008131992A1
WO2008131992A1 PCT/EP2008/053279 EP2008053279W WO2008131992A1 WO 2008131992 A1 WO2008131992 A1 WO 2008131992A1 EP 2008053279 W EP2008053279 W EP 2008053279W WO 2008131992 A1 WO2008131992 A1 WO 2008131992A1
Authority
WO
WIPO (PCT)
Prior art keywords
space cam
cam
helix angle
camshaft
space
Prior art date
Application number
PCT/EP2008/053279
Other languages
German (de)
English (en)
Inventor
Jens Schäfer
Siegfried Tisch
Sebastian Zwahr
Original Assignee
Schaeffler Kg
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 Schaeffler Kg filed Critical Schaeffler Kg
Publication of WO2008131992A1 publication Critical patent/WO2008131992A1/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
    • F01L13/0005—Deactivating valves
    • 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
    • F01L13/0036—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 the valves being driven by two or more cams with different shape, size or timing or a single cam profiled in axial and radial direction
    • F01L13/0042—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 the valves being driven by two or more cams with different shape, size or timing or a single cam profiled in axial and radial direction with cams being profiled in axial and radial direction
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D13/00—Controlling the engine output power by varying inlet or exhaust valve operating characteristics, e.g. timing
    • F02D13/02—Controlling the engine output power by varying inlet or exhaust valve operating characteristics, e.g. timing during engine operation
    • F02D13/06—Cutting-out cylinders
    • 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
    • F01L1/00—Valve-gear or valve arrangements, e.g. lift-valve gear
    • F01L1/12—Transmitting gear between valve drive and valve
    • F01L1/18—Rocking arms or levers
    • F01L1/181—Centre pivot rocking arms
    • 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
    • F01L1/00—Valve-gear or valve arrangements, e.g. lift-valve gear
    • F01L1/12—Transmitting gear between valve drive and valve
    • F01L1/18—Rocking arms or levers
    • F01L1/185—Overhead end-pivot rocking arms
    • 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
    • F01L2305/00—Valve arrangements comprising rollers
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T10/00—Road transport of goods or passengers
    • Y02T10/10—Internal combustion engine [ICE] based vehicles
    • Y02T10/12—Improving ICE efficiencies

Definitions

  • the present invention relates to a space cam valve drive for an internal combustion engine having at least one camshaft configured with one or more space cams which is axially movable in a camshaft axis.
  • the space cam valve drive comprises a cam follower which cooperates with the space cam to transmit the stroke information of the space cam contour on at least one valve.
  • Room cam valve drives in which the valve lift information is stored on the room cams, are generally known.
  • the three-dimensional space cam in combination with the cam follower contains at least the valve lift information in a further embodiment as well as the phase angle information.
  • the contact between the space cam and the cam follower can be done via tap rollers, with a sliding contact is possible.
  • the contact is usually formed as line contact between the elements, wherein the camshaft can be adjusted axially and the tapping element picks up different strokes by the changing cam contour.
  • the invention includes the technical teaching that the Jardinnockenkontur is formed such that the stroke of the valve is omitted in at least one axial position of the camshaft to provide a shutdown of the valve.
  • a space cam valve drive according to the invention comprises a space cam contour, which has a first helix angle, which merges into an enlarged second helix angle.
  • the helix angle describes the angle of the contact surface on the space cam contour relative to the camshaft axis, within which the space cam is axially movable.
  • the tapping element is in contact with the portion on the space cam contour which has the first helix angle, and to shut off the valvetrain the tapping member of the cam follower is in contact with the space cam contour which having the larger second skew angle.
  • the second helix angle is formed so large that the stroke of the valve is zero and the valve is turned off, since the contour in the space cam, the tap element is no longer sufficient or not deflected.
  • the minimum effective radius of the space cam contour does not end in an area which causes only a minimum valve lift, but this ends only in a range of a second helix angle, which is formed so that the valve lift is zero.
  • the camshaft comprises a plurality of space cams associated with valves of different cylinders of the internal combustion engine.
  • the camshaft further comprises at least one space cam, which has only the first helix angle, wherein at least one further space cam is provided on the same camshaft having the first and the second helix angle and allows a shutdown of the valves associated with this space cam.
  • the camshaft is designed with several room cams, which each carry cylinder-specific valve lift information. The result is a camshaft with space cam, which has different Jardinnockenkonturen or differing Hautno- ckenwellen, and wherein the space cam of the respective tap kinematics can be adjusted.
  • This option is particularly advantageous for engines with several cylinder banks, so that a cylinder bank can be completely or partially shut off, for example, while the other cylinder bank provides the operation of all cylinders.
  • the individual connection or disconnection of cylinder banks or individual cylinders is therefore only by axial adjustment of the camshaft.
  • noise advantages of the internal combustion engines through the lower valve lifts with a smaller valve lift leads to a lower noise, since fewer items are moved, and the moving parts are subjected to lower dynamics.
  • the camshaft associated with a first cylinder bank comprises a plurality of space cams which are formed at least partially with the first helix angle and the second helix angle and the camshaft associated with a second cylinder bank comprises a plurality of space cams which are formed only with the first helix angle are.
  • the camshaft is associated with a cylinder bank having four cylinders assigned in series, the camshaft having four space cams associated with the respective cylinders.
  • the space cams associated with the two middle cylinders are formed with the first and the second helix angle, wherein the space cams associated with the two outer cylinders are formed only with the first helix angle.
  • the tilt or drag levers include one or several tap rollers, which are in contact with the room cam.
  • the tapping rollers are received in a rocker assembly within the frame-like tilting or pivoting lever, so that they can follow the changing contour of the space cam.
  • a first tapping roller contacts the portion of the first helix angle, with a second tappet roller contacting the region of the second helix angle.
  • the effective stroke which is achieved in this operating situation, can be so small that the stroke of the at least one valve is omitted.
  • this can also be designed so that the effective radius of the cam corresponds to the base circle of the room cam. If the tapping element is in contact with this area of the room cam, then there is no change in radius with respect to the base circle of the space cam, so that this area can be described as a pure cylindrical shape. The tapping element rolls only over the outer circumference of the cylindrical portion, so that a stroke can be omitted even during rotation of the camshaft.
  • the transition between the helix angles is designed with radii so that overall a spherical contour of the space cam results with a "zero-stroke range.”
  • Modern production possibilities which include forming and machining operations, allow the design of any geometry of the space cam Therefore, with the radius of the base circle of the space cam is no production-technical obstacle, so that only the kinematics of the space cam must be adjusted with respect to their rolling motion on the spherical contour.
  • Figure 1 is a schematic view of a Jardinno- ckenventiltriebes invention for an internal combustion engine with four cylinders;
  • Figure 2a is a schematic side view of a Jardinnockenkontur having only the first helix angle (corresponds to the prior art);
  • Figure 2b is a schematic side view of a space cam contour with a first and a second helix angle, wherein the second helix angle is greater than the first helix angle.
  • 3a shows a set of curves of valve lifts over the cam angle, which can be generated with a cam according to FIG. 2a;
  • FIG. 3b shows a family of curves of valve lifts over the cam angle, which can be achieved with a space cam according to FIG. 2b.
  • FIG. 1 shows schematically a space cam valve drive 1 according to the invention.
  • This is designed for a four-cylinder, so that four space cam 2 are arranged on the camshaft 3.
  • the camshaft 3 is rotatably and axially movably mounted in the camshaft axis 4 and performs a rotational movement during operation of the space cam valve drive 1. Due to their rotational position, the two outer space cams can be recognized from their rear side so that the formation of the cam contour is not apparent.
  • the two middle space cams 2, however, are shown in a side view, in which the geometric configuration of the cam contour with the first helix angle ⁇ 1 and the second helix angle ⁇ 2 are shown. The representation of the helix angles ⁇ 1 and ⁇ 2 is only schematically shown again.
  • the tapping rollers 7 grip the contour region of the space cams 2, which is arranged adjacent to the first helix angle .alpha.1 in the second helix angle .alpha.2, causing the valves 6 to be shuttered off.
  • each cam follower 5 is assigned two valves 6, which execute a parallel stroke with one another. If the camshaft 3 is displaced axially to the right in relation to the image plane, the tapping rollers 7 come into contact with the area of the space cam 2, which has the second helix angle ⁇ 2. In this case, the stroke that is introduced into the Abgriffsrollen 7, so small that it runs to zero.
  • valves 6 are put out of operation, wherein the helix angles ⁇ 1 and ⁇ 2 can be designed individually for each space cam differently.
  • a cylinder-individual control of the internal combustion engine is possible to operate them as a function of their operating point with all cylinders in the low load range or only with individual cylinders.
  • FIG. 2a and 2b space cam 2 are shown, wherein the space cam in Figure 2a only the first helix angle ⁇ 1 and the space cam according to the representation in Figure 2b includes the first helix angle ⁇ 1 and the second helix angle ⁇ 2.
  • the space cam in Figure 2a can be considered as a conventional space cam (prior art), whereas the space cam in Figure 2b has the inventive design.
  • the camshaft axis 4 is schematically represented by a chelten line, around which the space cam 2 rotates.
  • the tapping rollers can pick off the region of the second helix angle ⁇ 2, so that the space cam valve drive is deactivated in the axial position of the space cam 2.
  • Valve strokes of 30, 60 and 100% are indicated, with the valve lift of 100% corresponding to the maximum stroke. Due to the second angle of inclination ⁇ 2, no lift is produced in the cam follower in the low load range, so that the valves and thus the charge changes of the associated cylinders are switched off when the internal combustion engine is idling.
  • FIG. 3 a shows the family of curves of a plurality of valve strokes which are plotted against the angle of rotation of the camshaft.
  • the valve lift is 3% of the maximum stroke, with a curve plotted for 30%, 60% and 100%.
  • the 3% valve lift corresponds to the idling of the cylinder, which does not correspond to the actual shutdown of the cylinder, but only corresponds to a low load range.
  • FIG. 3b shows a family of curves of four valve strokes, whereby the valve stroke is no longer visible according to idling. This runs along the abscissa, since the valve is switched off by the inventive design of the space cam according to the figure 2.
  • the family of curves shown in FIG. 3 a can be produced by a space cam according to FIG. 2 a, wherein the group of curves according to FIG. 3 b can be generated by a space cam 2 according to the invention, which is shown in FIG. 2 b.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Valve Device For Special Equipments (AREA)
  • Valve-Gear Or Valve Arrangements (AREA)

Abstract

L'invention concerne un mécanisme de distribution de cames spatiales (1) pour moteur à combustion interne, comprenant au moins un arbre à cames (3) avec une ou plusieurs cames spatiales (2). Ledit arbre à cames peut être déplacé dans le sens axial dans un axe d'arbre à cames (4). Il est prévu un basculeur (5) qui coopère avec les cames spatiales (2) afin de transmettre l'information de levée du contour des cames spatiales à au moins une soupape (6). Le contour de cames spatiales est conçu de sorte que la levée de la soupape (6) n'intervienne pas, dans au moins une position axiale de l'arbre à cames (3), afin d'induire un arrêt de la soupape (6).
PCT/EP2008/053279 2007-04-28 2008-03-19 Mécanisme de distribution à cames spatiales, à géométrie de cames spatiales modifiée WO2008131992A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE102007020129.1 2007-04-28
DE102007020129A DE102007020129A1 (de) 2007-04-28 2007-04-28 Raumnockenventiltrieb mit modifizierter Raumnockengeometrie

Publications (1)

Publication Number Publication Date
WO2008131992A1 true WO2008131992A1 (fr) 2008-11-06

Family

ID=38777502

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/EP2008/053279 WO2008131992A1 (fr) 2007-04-28 2008-03-19 Mécanisme de distribution à cames spatiales, à géométrie de cames spatiales modifiée

Country Status (2)

Country Link
DE (2) DE202007013509U1 (fr)
WO (1) WO2008131992A1 (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2017188877A1 (fr) * 2016-04-28 2017-11-02 Scania Cv Ab Entraînement de soupape

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102008029325A1 (de) * 2008-06-20 2009-12-24 Daimler Ag Ventiltriebvorrichtung
DE102008057835A1 (de) 2008-11-19 2010-05-20 Schaeffler Kg Nockenwelle mit dreidimensionalen Nocken
FR2946693B1 (fr) * 2009-06-16 2011-07-22 Renault Sas Moteur a combustion interne adapte a la deconnexion de cylindres et procede de commande correspondant
DE102019004810A1 (de) * 2019-05-21 2020-11-26 Karlheinrich Winkelmann Variable Ventilsteuerung für Ottomotoren und Dieselmotoren

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB215967A (en) * 1923-05-23 1924-05-22 Hans Henrik Nielsen Improvements in valve-gears for internal combustion motors
US20030192496A1 (en) * 2000-05-17 2003-10-16 Walters Christopher Paulet Melmoth Valve control mechanism
DE10316990A1 (de) * 2003-04-11 2004-10-28 Rolf Jung Vollvariabler mechanischer Ventiltrieb einer Brennkraftmaschine zur Betätigung von Gaswechselventilen
US20050022766A1 (en) * 2003-07-29 2005-02-03 Suzuki Motor Corporation Valve driving apparatus and internal combustion engine including the same

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB215967A (en) * 1923-05-23 1924-05-22 Hans Henrik Nielsen Improvements in valve-gears for internal combustion motors
US20030192496A1 (en) * 2000-05-17 2003-10-16 Walters Christopher Paulet Melmoth Valve control mechanism
DE10316990A1 (de) * 2003-04-11 2004-10-28 Rolf Jung Vollvariabler mechanischer Ventiltrieb einer Brennkraftmaschine zur Betätigung von Gaswechselventilen
US20050022766A1 (en) * 2003-07-29 2005-02-03 Suzuki Motor Corporation Valve driving apparatus and internal combustion engine including the same

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2017188877A1 (fr) * 2016-04-28 2017-11-02 Scania Cv Ab Entraînement de soupape
US10774699B2 (en) 2016-04-28 2020-09-15 Scania Cv Ab Valve drive

Also Published As

Publication number Publication date
DE102007020129A1 (de) 2008-10-30
DE202007013509U1 (de) 2007-11-29

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