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
  • 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
  • F01L1/34413—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 using composite camshafts, e.g. with cams being able to move relative to the camshaft
• • 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
  • F01L1/02—Valve drive
  • F01L1/04—Valve drive by means of cams, camshafts, cam discs, eccentrics or the like
  • F01L1/047—Camshafts
• • 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
  • F01L1/26—Valve-gear or valve arrangements, e.g. lift-valve gear characterised by the provision of two or more valves operated simultaneously by same transmitting-gear; peculiar to machines or engines with more than two lift-valves per cylinder
• • 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
  • F01L13/06—Modifications of valve-gear to facilitate reversing, braking, starting, changing compression ratio, or other specific operations for braking
• • 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
  • F02D13/04—Controlling the engine output power by varying inlet or exhaust valve operating characteristics, e.g. timing during engine operation using engine as brake

Definitions

• the invention relates to a valve train of a reciprocating internal combustion engine according to the preamble of patent claim 1 and deals with the problem of improving the working and / or braking operation of the internal combustion engine by special structural designs of the valve train and the possible valve control thereby possible.
• the invention is based on the general idea, in the case of an engine cylinder having at least two functionally identical valves operating as inlet or outlet valves, that the functionally identical valves act at least temporarily asynchronously on the respective associated valves during a four-stroke cycle.
• a camshaft with within this camshaft against each other rotatable, ie phase-adjustable cam.
• a primary and a secondary cam may be provided.
• the camshaft used is one which consists of two concentric mutually rotatable, mutually rotatable shafts, for example, the primary cam can be firmly connected to the outer shaft and the secondary cam can be firmly connected to the inner shaft when mounted on the outer shaft.
• the secondary cam can be rotated relative to the primary cam.
• Such camshafts are known as so-called adjustable camshafts prior art, so that their structure and function here no further explanations are necessary.
• FIG. 1 is a perspective schematic view of a four-valve engine cylinder with a two respectively adjustable camshaft valve train comprehensive
• valve control diagrams with a comparison between an engine operation in part a of the drawing and a braking operation in part b of the drawing
• FIG 3 shows a comparison between two valve control diagrams for a motor operation at medium speed (part a of the drawing) and low speed with respect to an improvement of the charge movement at low engine speeds (part b of the drawing)
• FIG. 4 is a comparison of valve timing diagrams for an engine speed (drawing part a) and a full engine load operation, with reference to an improved engine cylinder filling achievable by the control diagram (drawing part b);
• FIG. 5 is a comparison of valve timing diagrams for engine part load operation (drawing part a) and engine full load operation with respect to an improved engine cylinder mud (drawing part b).
• a camshaft as adjustment element acts on two intake valves 1 and two exhaust valves 2, namely a first camshaft 3 on the intake valves 1 and a second camshaft 4 on the exhaust valves 2.
• Both camshafts 3, 4 each have two mutually rotatable, that is phasenver constitue cam, namely a primary cam 5 and a secondary cam 6.
• Both camshafts 3, 4 consist of two mutually rotatable, concentric nested shafts, namely an inner shaft 7 and a tubular Outer shaft 8.
• the primary cam 5 are each firmly connected to the outer shaft and the secondary cam 6 fixed to the inner shaft 7.
• the fixedly connected to the inner shaft 7 secondary cam 6 are rotatable on the outside mounted shaft 8 and each rotatably connected by a pin 9 with the inner shaft 7.
• the camshafts 3, 4 can be driven for example via the respective outer shaft 8.
• the secondary cam 6 can be phase-shifted relative to the primary cam 5 rotating at the input speed of the respective camshaft.
• the invention consists in an engine cylinder with a valve device including valve train according to FIG. 1 in that at least two functionally identical valves, that is, the intake or exhaust valves 1; 2 each by a phase adjustment between the primary and secondary cam 5, 6 of the functionally identical valves 1; 2 actuating camshafts 3 or 4 can be actuated asynchronously against each other. It may be sufficient, only one type of functionally identical valves 1, 2, that is, either only the intake valves 1 or only the exhaust valves 2 each against each other to operate asynchronously. In addition, of course, a combination is possible, wherein for a realization of the invention in each case functionally identical valves 1; 2 asynchronously be present against each other and must be operated in certain engine operating conditions actually asynchronous. Examples of motor drive and brake operations obtainable according to the invention show various valve control diagrams in the figures explained below.
• crankshaft rotation angle " ⁇ " for a full power stroke over 360 ° are plotted on the abscissa, while on the ordinate in each case the stroke "h" of the valves 1, 2 is indicated.
• the engine operation control diagram in the figure part a shows that the maximum achievable strokes "h" of the two exhaust valves 2p, 2s are different, after which the secondary valve 2s has a considerably smaller maximum lift than the primary exhaust valve 2p. valve 2s during the "ejection" cycle almost during the entire cycle time with maximum opening stroke.
• the secondary exhaust valve 2s is driven asynchronously with respect to the primary exhaust valve 2p in such a manner that the secondary exhaust valve is already opened almost during the entire "work" cycle (A) Figure part b indicated by an arrow Pl.
• valves 1, 2 The opening and closing times of the valves 1, 2 are indicated by indicating the associated crankshaft angle " ⁇ " in the control diagrams.
• the braking power can be adjusted continuously.
• the control diagrams relate in the part of the figure a to a high-speed engine operation and in the part of the figure b to a NEN engine operation according to the invention with low speed.
• a phase shift in the direction of the arrow P2 of the secondary inlet valve Is shown in the figure part 2 an improved charge movement is achieved in the "intake" cycle (C) by the late opening of the secondary valve 2s, whereby a better combustion in this operating state can be achieved and the designations of the control diagrams in FIG. 3 correspond in meaning to those in FIG. 2.
• the control diagrams relate in the figure part a engine part load operation at high speed and in the figure part b a full engine load operation.
• the control diagrams relate in the part of the part a engine part load operation and in the figure part b a full engine operation according to the invention.
• the difference between the two control diagrams is that the exhaust valves 1, 2 are operated out of phase with each other.
• the secondary exhaust valve 2s is opened prematurely with respect to the primary exhaust valve 2p.
• the direction of the relevant phase shift between the two exhaust valves is indicated by an arrow P4.

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)
• Output Control And Ontrol Of Special Type Engine (AREA)
• Pistons, Piston Rings, And Cylinders (AREA)
• Gear-Shifting Mechanisms (AREA)

Applications Claiming Priority (2)

Publications (2)

Family

ID=39433926

Family Applications (1)

Country Status (6)

Families Citing this family (9)

Family Cites Families (39)

• 2007
  • 2007-02-16 DE DE102007007758A patent/DE102007007758A1/de not_active Withdrawn
• 2008
  • 2008-02-14 AT AT08716853T patent/ATE466171T1/de active
  • 2008-02-14 DE DE502008000602T patent/DE502008000602D1/de active Active
  • 2008-02-14 EP EP08716853A patent/EP2118454B1/fr active Active
  • 2008-02-14 US US12/527,343 patent/US9080472B2/en not_active Expired - Fee Related
  • 2008-02-14 WO PCT/EP2008/051805 patent/WO2008098991A1/fr active Application Filing
  • 2008-02-14 JP JP2009549832A patent/JP5398548B2/ja not_active Expired - Fee Related

Non-Patent Citations (1)

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