US20060243235A1 - Method for varying valve timing of an internal combustion engine - Google Patents

Method for varying valve timing of an internal combustion engine Download PDF

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Publication number
US20060243235A1
US20060243235A1 US10/538,018 US53801805A US2006243235A1 US 20060243235 A1 US20060243235 A1 US 20060243235A1 US 53801805 A US53801805 A US 53801805A US 2006243235 A1 US2006243235 A1 US 2006243235A1
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Prior art keywords
camshaft
internal combustion
valve
combustion engine
during
Prior art date
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Abandoned
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US10/538,018
Inventor
Dietmar Schwarzenthal
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Dr Ing HCF Porsche AG
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Individual
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Assigned to DR. ING. H.C.F. PORSCHE AKTIENGESELLSCHAFT reassignment DR. ING. H.C.F. PORSCHE AKTIENGESELLSCHAFT ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: SCHWARZENTHAL, DIETMAR
Publication of US20060243235A1 publication Critical patent/US20060243235A1/en
Abandoned 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
    • 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
    • F02D13/0203—Variable control of intake and exhaust valves
    • F02D13/0207—Variable control of intake and exhaust valves changing valve lift or valve lift and timing
    • 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
    • F01L1/34—Valve-gear or valve arrangements, e.g. lift-valve gear characterised by the provision of means for changing the timing of the valves without changing the duration of opening and without affecting the magnitude of the valve lift
    • F01L1/344—Valve-gear or valve arrangements, e.g. lift-valve gear characterised by the provision of means for changing the timing of the valves without changing the duration of opening and without affecting the magnitude of the valve lift changing the angular relationship between crankshaft and camshaft, e.g. using helicoidal gear
    • F01L1/356—Valve-gear or valve arrangements, e.g. lift-valve gear characterised by the provision of means for changing the timing of the valves without changing the duration of opening and without affecting the magnitude of the valve lift changing the angular relationship between crankshaft and camshaft, e.g. using helicoidal gear making the angular relationship oscillate, e.g. non-homokinetic drive
    • 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
    • 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
    • F01L2800/00—Methods of operation using a variable valve timing mechanism
    • 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

  • This invention relates to a technique for changing the valve timing of an internal combustion engine.
  • the timing of an intake or exhaust valve of an internal combustion engine can be changed by first changing the position of the intake camshaft in relation to the exhaust camshaft by means of a camshaft actuator.
  • the opening and closing times of the intake valves are thereby adapted to a certain RPM ranges by two separate intake timings and the valve overlap, while the valve opening duration and the valve stroke remain the same (see, e.g. German document DE 38 76 762).
  • the prior art includes variable valve trains in which the valve opening times as well as the valve opening widths are adapted to the operating modes of the engines.
  • German document DE 196 06 054 C2 describes a variable valve train of an internal combustion engine in which the valve stroke can be adjusted between two settings with the aid of a switchable bucket tappet.
  • the assembly is equipped with a device that adjusts the intake and exhaust times of the gas exchange valve, allowing improved filling of the cylinder over a large range of RPMs.
  • the invention suggests adjusting the camshaft in the direction of “late” during a valve stroke while adjusting, that is correcting the camshaft in the direction of “early,” during the immediately subsequent base circle phase of the affected camshaft.
  • the invention suggests adjusting the camshaft toward “early” during a valve stroke while adjusting, that is correcting the camshaft in the direction of “late,” during the immediately subsequent base circle phase of the camshaft in question.
  • valve timing described is particularly suited for a double-rowed, 6-cylinder engine with a symmetrical ignition sequence per cylinder bank, since, in engines of this type, an even distribution of valve stroke and base circle phase on the camshaft are present.
  • the inventive procedure described is also suited for combination with a variable valve train, in which a valve stroke cross-over is present, because, as illustrated in the 2-setting valve cross-over exemplified in German document DE 196 06 054 C2, the base circle phase of the cam is especially long with small valve strokes.
  • the drawing FIGURE is a diagram showing the valve stroke on the intake side of the internal combustion machine as well as the angular velocity of the camshaft.
  • valve timing can be continuously adjusted on the intake side, while, because of the 2-setting valve cross-over, valve stroke curve A can be adjusted with a small cam lobe and valve stroke curve B can be adjusted with a large cam lobe as the diagram illustrates.
  • valve timing as well as the valve stroke are controlled as a function of the operating parameters of the internal combustion engine such as load or RPM.
  • a possible field of the valve train in which the various operating modes of the valve train are plotted as a function of RPM and load of the internal combustion engine is described and illustrated in German document DE 196 06 054 C2.
  • a continuous adjustment of the angle of rotation of the intake camshaft to the exhaust camshaft and to the crankshaft of the internal combustion engine is present, only valve stroke is shifted toward “early” or “late.”
  • the angular velocity of the camshaft is, up to the actual adjustment process, constant, as shown by the dashed line C in the diagram.
  • the intake camshaft is adjusted toward “late” in the amount ⁇ , while the attitude of rotational angle of the camshaft is reset, that is, corrected toward “early” during the immediately subsequent base circle, preferably in the amount ⁇ .
  • This process is repeated, provided that the valve opening duration for the current operating mode of the internal combustion engine is reduced relative to the “normal” valve opening duration, which is determined by the valve cam lobes.
  • the valve opening, curve D, illustrated in the diagram is thereby provided.
  • curve D is the angular velocity of the camshaft, curve E, whereby it is evident that, during the valve stroke, a positive acceleration of the camshaft toward “late” occurs, while a negative acceleration of the camshaft toward “early” occurs due to the resetting during the base circle phase of the affected cam lobe.
  • the camshaft is adjusted toward “early” in the amount ⁇ during the valve stroke, while the camshaft is corrected toward “late” during the base circle, preferably in the amount of ⁇ .
  • the proposed procedure makes it possible to implement further valve stroke geometry with the same cam lobe shape.
  • An influence of the valve stroke curve is then particularly important if a high adjustment velocity can be implemented with the camshaft actuator.
  • An electrically controlled camshaft actuator of the prior art is particularly advantageous in this respect.
  • the previously described procedure is, as has already been mentioned, especially suited for double-rowed 6-cylinder engines, without any restrictions to this configuration, because, in the case of the 1-6-2-4-3-5 ignition sequence used in the Porsche boxer engine, a symmetrical ignition sequence per cylinder bank can be produced, thereby ensuring even distribution of valve stroke and base circle phase on the camshaft.
  • the procedure can also be used on the exhaust side of the internal combustion engine, wherein the exhaust camshaft is also equipped with the necessary camshaft actuator in this case.

Abstract

A technique is used for adjusting the valve timing of an internal combustion engine with a cam shaft and a cam lobe displaced at a rotational angle with respect to one another. Under interposition of a cam following element, such as, for example, a bucket tappet, the cam shaft and the cam lobe work together with intake or exhaust valves as well as the camshaft actuator present on the camshaft, through which the position and/or the attitude of rotation of the camshaft to the crankshaft can be changed. To decrease the valve opening time, the camshaft can be adjusted toward hate” during a valve stroke, while the camshaft is adjusted toward “early” during the immediately subsequent base circle phase of the affected camshaft. To increase the valve opening times the camshaft can be adjusted toward “early” during a valve stroke, while the camshaft is adjusted toward “late” during the immediately subsequent base circle phase of the affected camshaft. This technique permits adjustment of the angular attitude of the camshaft as well influence on the valve stroke curve.

Description

    BACKGROUND AND SUMMARY OF THE INVENTION
  • This invention relates to a technique for changing the valve timing of an internal combustion engine.
  • It is commonly known that the timing of an intake or exhaust valve of an internal combustion engine can be changed by first changing the position of the intake camshaft in relation to the exhaust camshaft by means of a camshaft actuator. The opening and closing times of the intake valves are thereby adapted to a certain RPM ranges by two separate intake timings and the valve overlap, while the valve opening duration and the valve stroke remain the same (see, e.g. German document DE 38 76 762). Furthermore the prior art includes variable valve trains in which the valve opening times as well as the valve opening widths are adapted to the operating modes of the engines. German document DE 196 06 054 C2, for example, describes a variable valve train of an internal combustion engine in which the valve stroke can be adjusted between two settings with the aid of a switchable bucket tappet. The assembly is equipped with a device that adjusts the intake and exhaust times of the gas exchange valve, allowing improved filling of the cylinder over a large range of RPMs.
  • It is an object of this invention to expand the functional range of a camshaft actuator in such a way that, in addition to adjusting the valve timing by “shifting” the valve stroke curve toward intake or exhaust for an “early” or “late” opening, an adjustment of the valve opening time can be achieved.
  • This object can be achieved through the claimed features.
  • For decreasing the valve opening time, the invention suggests adjusting the camshaft in the direction of “late” during a valve stroke while adjusting, that is correcting the camshaft in the direction of “early,” during the immediately subsequent base circle phase of the affected camshaft. To increase the valve opening time, which is determined by the shape of the cam lobe, the invention suggests adjusting the camshaft toward “early” during a valve stroke while adjusting, that is correcting the camshaft in the direction of “late,” during the immediately subsequent base circle phase of the camshaft in question. By following these measures, the valve opening duration can be adjusted in an advantageous manner. With the use of a camshaft actuator, a range of function is thereby achieved, which is otherwise possible only with a variable valve train system.
  • Based on the features specified in dependent claims, additional advantageous configurations of the invention are also possible.
  • The technique for changing valve timing described is particularly suited for a double-rowed, 6-cylinder engine with a symmetrical ignition sequence per cylinder bank, since, in engines of this type, an even distribution of valve stroke and base circle phase on the camshaft are present.
  • The inventive procedure described is also suited for combination with a variable valve train, in which a valve stroke cross-over is present, because, as illustrated in the 2-setting valve cross-over exemplified in German document DE 196 06 054 C2, the base circle phase of the cam is especially long with small valve strokes.
  • An embodiment of the invention is described in further detail in the following description.
    • BRIEF DESCRIPTION OF THE DRAWING FIGURE
  • The drawing FIGURE is a diagram showing the valve stroke on the intake side of the internal combustion machine as well as the angular velocity of the camshaft.
    • DETAILED DESCRIPTION OF THE INVENTION
  • The inventive procedure is described based on a 6-cylinder boxer engine, both camshafts of which are equipped with camshaft actuator as well as a two-setting valve stroke change-over on the intake side. Internal combustion engines of this type are made by the Porsche Corporation under the model series 996 “VarioCamPlus-System.” The construction and function of this variable valve train therefore does not need to be described in further detail. With the aid of a hydraulically-activated camshaft actuator, the valve timing can be continuously adjusted on the intake side, while, because of the 2-setting valve cross-over, valve stroke curve A can be adjusted with a small cam lobe and valve stroke curve B can be adjusted with a large cam lobe as the diagram illustrates. The valve timing as well as the valve stroke are controlled as a function of the operating parameters of the internal combustion engine such as load or RPM. A possible field of the valve train in which the various operating modes of the valve train are plotted as a function of RPM and load of the internal combustion engine is described and illustrated in German document DE 196 06 054 C2. As long as a continuous adjustment of the angle of rotation of the intake camshaft to the exhaust camshaft and to the crankshaft of the internal combustion engine is present, only valve stroke is shifted toward “early” or “late.” The angular velocity of the camshaft is, up to the actual adjustment process, constant, as shown by the dashed line C in the diagram.
  • Below the inventive procedure for decreasing or increasing the valve opening duration with the aid of a camshaft actuator is described in further detail. The technique is particularly useful, when the internal combustion engine is driven by small valve strokes, because the base circle phase of the “small cam lobe” is particularly long.
  • 1. Decreasing the Valve Stroke Curve.
  • During a valve stroke, the intake camshaft is adjusted toward “late” in the amount Δφ, while the attitude of rotational angle of the camshaft is reset, that is, corrected toward “early” during the immediately subsequent base circle, preferably in the amount Δφ. This process is repeated, provided that the valve opening duration for the current operating mode of the internal combustion engine is reduced relative to the “normal” valve opening duration, which is determined by the valve cam lobes. The valve opening, curve D, illustrated in the diagram is thereby provided. Corresponding to valve opening, curve D, is the angular velocity of the camshaft, curve E, whereby it is evident that, during the valve stroke, a positive acceleration of the camshaft toward “late” occurs, while a negative acceleration of the camshaft toward “early” occurs due to the resetting during the base circle phase of the affected cam lobe.
  • 2. Increasing the Valve Stroke Curve.
  • In this case, the camshaft is adjusted toward “early” in the amount Δφ during the valve stroke, while the camshaft is corrected toward “late” during the base circle, preferably in the amount of Δφ.
  • The proposed procedure makes it possible to implement further valve stroke geometry with the same cam lobe shape. An influence of the valve stroke curve is then particularly important if a high adjustment velocity can be implemented with the camshaft actuator. An electrically controlled camshaft actuator of the prior art is particularly advantageous in this respect. The previously described procedure is, as has already been mentioned, especially suited for double-rowed 6-cylinder engines, without any restrictions to this configuration, because, in the case of the 1-6-2-4-3-5 ignition sequence used in the Porsche boxer engine, a symmetrical ignition sequence per cylinder bank can be produced, thereby ensuring even distribution of valve stroke and base circle phase on the camshaft. The procedure can also be used on the exhaust side of the internal combustion engine, wherein the exhaust camshaft is also equipped with the necessary camshaft actuator in this case.

Claims (9)

1-3. (canceled)
4. A method for changing a valve timing of an internal combustion engine with a camshaft and a cam lobe displaced at a rotational angle with respect to each other, the camshaft and the cam lobe, under interposition of at least one appropriate cam following element, acting together with intake or exhaust valves of the internal combustion engine as well as with a camshaft actuator situated on the camshaft, through which at least one of a position and a rotational attitude of the camshaft can be adjusted for a crankshaft, comprising:
(a) adjusting the camshaft toward “late” during a valve stroke and toward “early” during an immediately subsequent base circle phase of the camshaft to decrease a valve opening time, and
(b) adjusting the camshaft toward “early” during a valve stroke and toward “late” during an immediately subsequent base circle phase of the camshaft to increase the valve opening time.
5. The method as claimed in claim 4, wherein the internal combustion engine is a double-rowed, 6-cylinder engine with symmetrical ignition sequence for each cylinder bank.
6. The method as claimed in claim 4, wherein the internal combustion engine is equipped with a device for valve stroke change-over.
7. The method as claimed in claim 4, wherein the cam following element is a bucket tappet.
8. The method as claimed in claim 5, wherein the internal combustion engine is equipped with a device for valve stroke change-over.
9. The method as claimed in claim 7, wherein the internal combustion engine is a double-rowed, 6-cylinder engine with symmetrical ignition sequence for each cylinder bank.
10. The method as claimed in claim 7, wherein the internal combustion engine is equipped with a device for valve stroke change-over.
11. The method as claimed in claim 9, wherein the internal combustion engine is equipped with a device for valve stroke change-over.
US10/538,018 2002-12-13 2003-10-24 Method for varying valve timing of an internal combustion engine Abandoned US20060243235A1 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
DE10258249.1 2002-12-13
DE10258249A DE10258249A1 (en) 2002-12-13 2002-12-13 Method for changing the valve timing of an internal combustion engine
PCT/EP2003/011782 WO2004055336A1 (en) 2002-12-13 2003-10-24 Method for varying valve timing of an internal combustion engine

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US (1) US20060243235A1 (en)
EP (1) EP1573178B1 (en)
JP (1) JP2006509949A (en)
AT (1) ATE468474T1 (en)
DE (2) DE10258249A1 (en)
WO (1) WO2004055336A1 (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20080017150A1 (en) * 2004-09-15 2008-01-24 Yamaha Hatsudoki Kabushiki Kaisha Variable Valve Drive Device, Engine, and Motorcycle
US20080092837A1 (en) * 2005-01-18 2008-04-24 Borgwarner Inc. Valve Event Reduction Through Operation of a Fast-Acting Camshaft Phaser

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102012022554A1 (en) 2012-11-17 2014-05-22 Daimler Ag Valve train device for motor car, has adjusting unit to accelerate or delay a camshaft during actuation of valve in operation state, based on triggered valve lift course for acceleration or delay operation of camshaft
DE102014000498A1 (en) * 2014-01-16 2015-07-16 Daimler Ag Valve train device for an internal combustion engine

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US5361736A (en) * 1990-07-13 1994-11-08 Lancelot Phoenix Variable valve timing
US5398502A (en) * 1992-05-27 1995-03-21 Fuji Jukogyo Kabushiki Kaisha System for controlling a valve mechanism for an internal combustion engine
US5427078A (en) * 1992-09-28 1995-06-27 Mazda Motor Corporation Supercharging apparatus for use in an internal combustion engine
US6055948A (en) * 1995-10-02 2000-05-02 Hitachi, Ltd. Internal combustion engine control system
US6453871B1 (en) * 1993-12-28 2002-09-24 Hitachi, Ltd. Apparatus for and method of controlling internal combustion engine

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US3633555A (en) * 1969-06-27 1972-01-11 Ass Eng Ltd Variable camshaft mechanism
JPH01134013A (en) * 1987-11-19 1989-05-26 Honda Motor Co Ltd Valve system control method and device for internal combustion engine
DE3901721A1 (en) * 1989-01-21 1990-08-02 Daimler Benz Ag V-DESIGN INTERNAL COMBUSTION ENGINE
DE19606054C2 (en) * 1996-02-19 1998-07-30 Porsche Ag Valve train of an internal combustion engine
DE19608533A1 (en) * 1996-03-06 1997-09-11 Dummann Hans Peter Timing control for internal combustion engine
JP3403948B2 (en) * 1998-08-05 2003-05-06 本田技研工業株式会社 Variable intake device for V-type multi-cylinder internal combustion engine
DE19855984A1 (en) * 1998-12-04 2000-06-15 Porsche Ag Timing gear for IC engine has one intake valve with regular actuation associated with least frequent operational parameters executing a small stroke when switched off

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5361736A (en) * 1990-07-13 1994-11-08 Lancelot Phoenix Variable valve timing
US5398502A (en) * 1992-05-27 1995-03-21 Fuji Jukogyo Kabushiki Kaisha System for controlling a valve mechanism for an internal combustion engine
US5427078A (en) * 1992-09-28 1995-06-27 Mazda Motor Corporation Supercharging apparatus for use in an internal combustion engine
US6453871B1 (en) * 1993-12-28 2002-09-24 Hitachi, Ltd. Apparatus for and method of controlling internal combustion engine
US6055948A (en) * 1995-10-02 2000-05-02 Hitachi, Ltd. Internal combustion engine control system

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20080017150A1 (en) * 2004-09-15 2008-01-24 Yamaha Hatsudoki Kabushiki Kaisha Variable Valve Drive Device, Engine, and Motorcycle
US20080092837A1 (en) * 2005-01-18 2008-04-24 Borgwarner Inc. Valve Event Reduction Through Operation of a Fast-Acting Camshaft Phaser
US7568458B2 (en) 2005-01-18 2009-08-04 Borgwarner Inc. Valve event reduction through operation of a fast-acting camshaft phaser

Also Published As

Publication number Publication date
DE10258249A1 (en) 2004-07-15
WO2004055336A1 (en) 2004-07-01
ATE468474T1 (en) 2010-06-15
DE50312727D1 (en) 2010-07-01
EP1573178A1 (en) 2005-09-14
EP1573178B1 (en) 2010-05-19
JP2006509949A (en) 2006-03-23

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AS Assignment

Owner name: DR. ING. H.C.F. PORSCHE AKTIENGESELLSCHAFT, GERMAN

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:SCHWARZENTHAL, DIETMAR;REEL/FRAME:018030/0115

Effective date: 20050504

STCB Information on status: application discontinuation

Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION