Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
  • F02B23/00—Other engines characterised by special shape or construction of combustion chambers to improve operation
  • F02B23/08—Other engines characterised by special shape or construction of combustion chambers to improve operation with positive ignition
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
  • F02B17/00—Engines characterised by means for effecting stratification of charge in cylinders
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02F—CYLINDERS, PISTONS OR CASINGS, FOR COMBUSTION ENGINES; ARRANGEMENTS OF SEALINGS IN COMBUSTION ENGINES
  • F02F1/00—Cylinders; Cylinder heads 
  • F02F1/24—Cylinder heads
  • F02F1/42—Shape or arrangement of intake or exhaust channels in cylinder heads
  • F02F1/4214—Shape or arrangement of intake or exhaust channels in cylinder heads specially adapted for four or more valves per cylinder
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
  • F02B1/00—Engines characterised by fuel-air mixture compression
  • F02B1/02—Engines characterised by fuel-air mixture compression with positive ignition
  • F02B1/04—Engines characterised by fuel-air mixture compression with positive ignition with fuel-air mixture admission into cylinder
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02F—CYLINDERS, PISTONS OR CASINGS, FOR COMBUSTION ENGINES; ARRANGEMENTS OF SEALINGS IN COMBUSTION ENGINES
  • F02F1/00—Cylinders; Cylinder heads 
  • F02F1/24—Cylinder heads
  • F02F2001/244—Arrangement of valve stems in cylinder heads
  • F02F2001/247—Arrangement of valve stems in cylinder heads the valve stems being orientated in parallel with the cylinder axis
• • 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 invention relates to a method and a device for introducing a stratified charge in gasoline engines, in which a richer layer is located in the area of the spark plug and in the rest of the area or below, the lean mixture.
• Stratified charge in gasoline engines enables operation with very lean mixtures. Consumption figures such as in the case of the diesel engine, combined with the low CO, CH and NOx fractions in the exhaust gas, are to be achieved.
• the real problem with this stratified charge is that the ignition process takes place perfectly, although there is predominantly a mixture larger than lambda 1.3 in the cylinder. The more lean the mixture, the lower the pollutant content.
• the object of the invention is to provide a method for the ignition of this lean mixture that still achieves perfect combustion with a relatively very lean mixture.
• the solution to the problem according to the invention is that the richer mixture is supplied to the spark plug under pressure.
• the essence of the present invention is that the fatter mixture is directed to the spark plug, as with a jet-like accelerated jet, and the lean mixture stored in the combustion chamber is initially not brought into contact with this targeted jet of the richer mixture, but only with the fatter one Mixture initiates the ignition and only then mixes and ignites with the lean mixture with the resulting ignition jet.
• the richer mixture is selectively fed to the spark plug via at least one pinch gap, it being essential that the richer mixture accelerates in a jet-like manner into the combustion chamber and flows into the combustion chamber on the opposite side of the Combustion chamber arranged spark plug hits, while the lean mixture is introduced into the combustion chamber outside the pinch gap via other valves.
• the resulting ignition jet is then used to ignite the lean mixture stored in the combustion chamber, which due to the initial ignition by the ignition jet then ignites well and burns practically without residue.
• a further embodiment of the present invention provides that a further improvement in the directivity of the richer mixture in the direction of the spark plug is achieved in that the pinch gap already present according to the first embodiment is extended in the seal on the spark plug by the fact that it extends so far into the existing combustion chamber that it protrudes hi into the intermediate space between the valves arranged above in the cylinder head wall.
• the squeeze length in the direction of the spark plug is considerably lengthened and a further acceleration of the richer gas and an improvement in the directional effect on the spark plug is thus achieved.
• This exemplary embodiment therefore assumes that there is a relatively long pinch gap which extends almost over the entire width of the combustion chamber and which accelerates the rich mixture from the inlet valve in the direction of the spark plug through the combustion chamber and directs it towards the spark plug.
• This downstream, central pinch gap specifically takes over the mixture which has already been accelerated by the first pinch gap and accelerates it further, thereby achieving an extraordinarily favorable acceleration of the mixture emerging from the mouth of this pinch gap in the direction of the spark plug.
• the direction of the middle pinch gap can now be made to deviate from the direction of the longer, outer pinch gap.
• a first embodiment accordingly provides that the mixture entering the combustion chamber via the longer pinch gaps occurs approximately in the middle of the combustion chamber (based on the height of the combustion chamber) and produces essentially no rotation, while the middle pinch gap is directed towards the upper cylinder head wall and in connection with deflection means in the combustion chamber then produces a strongly rotating middle flow roller which acts on the spark plug.
• the outer pinch gap has the same inclination as the middle pinch gap and that both pinch gaps are directed obliquely against the upper cylinder head wall.
• the flow rollers produced by the longer nip then rotate as well as the middle flow roller which is generated by the middle nip. If the rich mixture is now supplied to the spark plug under pressure and rotation in the combustion chamber is achieved at the same time, a much better and more extensive ignition process is guaranteed.
• the combustion chamber on one side consists of a trough-shaped depression formed in the piston head and associated rounded surfaces of the cylinder head that there is a pinch gap on the other side of the combustion chamber is formed, on the one hand from a surface of the piston crown and on the other hand from an assigned surface of the cylinder head, that the first nip opens into the combustion chamber and there, depending on the direction of this nip, either only a laminar, non-rotating Pinch flow or - if it is against the upper one
• Cylinder head wall directed nip acts - a first rotating flow roller generates; whereby the second pinch gap is formed between the piston crown and the associated surface of the cylinder head approximately in the middle of the first pinch gap and in the extension of the first pinch gap and generates a second rotating flow roller which is directed towards the spark plug.
• a first nip Seen across the width of the combustion chamber, a first nip is arranged, which ensures that the fatter mixture is fed through the first inlet valve, which feeds it into the combustion chamber and generates a first rotating flow roller there.
• a further pinch gap which extends the first pinch gap, is arranged in the center with respect to this first inlet valve, likewise approximately in the middle of the piston head, this pinch gap producing a second rotating flow roller which is directed precisely at the spark plug.
• the central, rapidly rotating flow roller which now contains the pilot injection, is rapidly sideways' in the laterally outer rotating flow rollers continue to be carried ignited extremely quickly over the spreading jet ignition and safely, so that in total a secure cross-ignition of the Rotie in the combustion chamber ⁇ mixture is guaranteed.
• FIG. 1 top view of the piston crown of a piston with a combustion chamber according to the invention and with the dashed position of the valves and intake pipes arranged above it in the cylinder head in a first embodiment, with a first, long pinch gap,
• Figure 2 Section along the line A-B in Figure 1
• FIG. 3 top view of the piston crown of a piston with a combustion chamber according to the invention, with the position of the valves and intake pipes arranged above it in dashed lines, with a longer pinch gap and a downstream middle pinch gap,
• FIG. 4 section along line A-B in FIG. 3,
• FIG. 5 curves of the valve opening times of the three valves
• Figure 6 Section along the line VI-VI in Figure 2 through the combustion chamber.
• a piston 1 which is shown in the illustration according to FIGS. 2 and 4 in its top dead center position.
• the cylinder 11 is covered at the top by a cylinder head 10, in which, as shown in FIG. 1, three valves 2, 3, 4 are arranged, the valves 2, 3 being designed as intake valves and the valve 4 as an exhaust valve.
• the inlet valve 3 receives its mixture via the intake pipe 7, while the other inlet valve 2 receives its mixture via a further intake pipe 6.
• the outlet of the outlet valve 4 is not shown for the sake of clarity.
• the combustion chamber 12 shown in FIGS. 1 to 4 is formed between the piston crown 27 of the piston 1 and the associated surfaces of the cylinder head 10.
• the same parts are designated by the same reference numerals.
• a trough-like depression 28 is machined on one side, which, together with the associated, overlying surfaces of the cylinder head, looks roughly profiled, as shown in FIG. 2.
• Corresponding deflection bends 26 are incorporated in the trough-like recess 28 and the same deflection bends are also located in the parts of the cylinder head located above.
• FIG 1 and 2 show a first embodiment of how a richer mixture can be supplied under pressure to the spark plug 5 arranged opposite the inlet valve 2 for the richer mixture in the combustion chamber.
• the piston crown 27 here forms a pinch gap 16 which extends approximately over the width of the combustion chamber 12.
• the pinch gap 16 is here by an essentially straight surface of the piston crown 27 formed in connection with an opposite, straight surface in the cylinder head 10.
• the inlet valve 2 for the inlet of the richer mixture is arranged.
• the inlet valve 2 has already closed again and the rich mixture has almost been shot through the pinch gap 16 in the form of a pinch column flow 29 into the combustion chamber 12, where this pinch column flow 29 hits the spark plug 5 and then the ignition is started.
• the ignition jet 22 resulting in the rich mixture (see FIG. 4) then serves to 'promote the rotation in this area and ' completely ignite the lean mixture stored in the combustion chamber.
• the pinch gap 16 is also arranged obliquely and in the form of a wedge-shaped combustion chamber directs its pinch flow 4-9 exactly to the spark plug 5 arranged opposite.
• the exemplary embodiment in FIGS. 3 and 4 differs from the first-mentioned exemplary embodiment in FIGS. 1 and 2 in that a further, central pinch gap 18 is provided behind the first pinch gap 16.
• the first pinch gap 16 is again formed in the piston crown 27 on the left-hand side in FIG. 4, which on the one hand consists of a straight surface of the piston crown 27, which cooperates with an associated straight surface of the wall of the cylinder head 10 above it.
• the pinch gap 16 in turn extends essentially according to FIG. 3 over the entire width of the combustion chamber, the squeeze column flow 29 emerging from this squeeze column being directed straight into the combustion chamber 12 in a first exemplary embodiment and then not producing any external, rotating flow rollers 39.
• a middle, rotating flow roller 38 is then generated only through the middle nip.
• the pinch gap 16 is also directed obliquely against the underside of the valves 3, 4 and the pinch gap flow 29 flowing therefrom then becomes deflected on the associated arcuate surfaces of the wall of the cylinder head 10 and the associated deflection bend 26 of the recess 28 in the piston head, so that a flow roller 39 (see FIG. 6) of a mixture 23 deflected in the direction of the arrow 21 results.
• the flow roller 39 is also deflected at the bottom of the depression 28 in the direction of the arrow 20, so that the wide pinch gap 16 extends across the entire width of the combustion chamber 12. Flow roller 39 results.
• the wide pinch gap 16 is extended in the middle by a further pinch gap 19, this pinch gap extending into the space between the valves 3, 4 arranged above it in the cylinder head 10.
• the pinch gap 19 is thus an extension of the wider pinch gap 16 arranged behind it and receives its mixture from the last-mentioned pinch gap 16 at a relatively high initial speed.
• the inlet valve 3 first opens, through which pure combustion air may be drawn in with the addition of exhaust gas or a very lean mixture. Only later does the inlet valve 2 open which is drawn in via a carburetor or injection of a richer mixture.
• the engine receives pure combustion air or very lean mixture in the lower part of the combustion chamber and later a mixture of combustion air or lean mixture with a richer mixture.
• the cylinder 11 In the upper part of the cylinder filling, the cylinder 11 only receives a richer mixture via the opened inlet valve 2 while the inlet valve 3 is already closed to obtain high final acceleration through the second pinch gap 19 and then to enter the combustion chamber 12 in the form of a highly accelerated pinch gap flow 18 and to hit the opposite spark plug 5. ..
• the ignition jet 22 generated in this way is introduced approximately parallel to the flow rollers 38, 39 rotating in the combustion chamber 12, so that there is a further strong acceleration of the flow rollers 38, 39 and at the same time the ignition jet is delivered via the flow roller 38 rotating rapidly in the middle is carried into the laterally flowing nip streams 29 or into the laterally rotating flow rollers 39 and thereby also leads to a reliable ignition of these nip streams 29 or stream rollers 39.
• the middle pinch gap 19 is designed as a pinch nose 30 which, according to the illustration in FIG. 3 and FIG. 6, extends approximately wedge-shaped in plan view into the space between the valves 3, 4 arranged above it.
• the pinch nose 30 has a front, approximately flat, end surface 31, which is adjoined by wedge-shaped beveled side surfaces 32. It is important here that the middle pinch gap 19 is extended as far as possible in the direction of the spark plug 5 in order to direct a straight and directed short flow of the rich mixture to the spark plug 5.
• the total mixture via channels 6, 7 to valves 2, 3 is generated only by a carburetor or an injection device and by adding combustion air in front of valve 3 at the point 9 of this mixture became emaciated.
• This air additive can be in an intermediate piece 8 between
• Intake manifold and cylinder head are inserted.
• the control takes place via a throttle valve or other valve, which is connected with the control of the opening of the carburetor throttle valve.
• the throttle valve for the additional air is closed.
• Air can also be supplied with exhaust gas or a mixture of exhaust gas and combustion air.
• Both valves 2, 3 have separate intake pipes 6, 7, one intake pipe 6 being supplied with a richer mixture and the other intake pipe 7 being supplied with a lean mixture or pure combustion air.
• valve 3 is controlled w ie usual with normal opening and closing, hours, about 40 BTDC to bottom dead center, or rather closes by curve 14.
• the cam of the outlet valve 4 is ange ⁇ to 50 with curve 13 leads.
• the inlet valve 2 opens later by approximately 20-40 and closes later than the other inlet valve 3, see curve 15. All. Exemplary embodiments described above are characterized in that one half of the combustion chamber is in a trough-shaped recess in the piston crown and the other half of the combustion chamber is in the cylinder head. Within the scope of the present invention, special protection is also claimed for the fact that the combustion chamber is located essentially in the upper cylinder head. This means that the trough-shaped recess in the piston crown is omitted and the piston crown is flat in this area and essentially forms a continuous plane with the right pinch gap.

Applications Claiming Priority (4)

Publications (1)

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ID=25837003

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• 1985
  • 1985-12-20 DE DE19853545440 patent/DE3545440A1/de active Granted
• 1986
  • 1986-10-14 WO PCT/EP1986/000586 patent/WO1987002415A1/de not_active Application Discontinuation
  • 1986-10-14 AU AU65999/86A patent/AU6599986A/en not_active Abandoned
  • 1986-10-14 EP EP86906307A patent/EP0237569A1/de not_active Withdrawn
  • 1986-10-14 JP JP61505939A patent/JPH01500045A/ja active Pending

Non-Patent Citations (1)

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