EP0202216A2 - Procédé pour balayer un moteur à deux temps à balayage à flux inversé et moteur fonctionnant selon ce procédé - Google Patents

Procédé pour balayer un moteur à deux temps à balayage à flux inversé et moteur fonctionnant selon ce procédé Download PDF

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Publication number
EP0202216A2
EP0202216A2 EP86890118A EP86890118A EP0202216A2 EP 0202216 A2 EP0202216 A2 EP 0202216A2 EP 86890118 A EP86890118 A EP 86890118A EP 86890118 A EP86890118 A EP 86890118A EP 0202216 A2 EP0202216 A2 EP 0202216A2
Authority
EP
European Patent Office
Prior art keywords
overflow channels
overflow
outlet channel
crankcase
channels
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.)
Granted
Application number
EP86890118A
Other languages
German (de)
English (en)
Other versions
EP0202216B1 (fr
EP0202216A3 (en
Inventor
Diethard Dipl.-Ing. Plohberger
Josef Dipl.-Ing. Greier
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.)
AVL List GmbH
Original Assignee
AVL List GmbH
AVL Gesellschaft fuer Verbrennungskraftmaschinen und Messtechnik mbH
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 AVL List GmbH, AVL Gesellschaft fuer Verbrennungskraftmaschinen und Messtechnik mbH filed Critical AVL List GmbH
Publication of EP0202216A2 publication Critical patent/EP0202216A2/fr
Publication of EP0202216A3 publication Critical patent/EP0202216A3/de
Application granted granted Critical
Publication of EP0202216B1 publication Critical patent/EP0202216B1/fr
Expired 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
    • F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
    • F02B25/00—Engines characterised by using fresh charge for scavenging cylinders
    • F02B25/20—Means for reducing the mixing of charge and combustion residues or for preventing escape of fresh charge through outlet ports not provided for in, or of interest apart from, subgroups F02B25/02 - F02B25/18

Definitions

  • the invention relates to a method for changing the charge in two-stroke internal combustion engines with reverse purge, with the piston-controlled outlet channel and at least two overflow channels arranged on both sides of the outlet channel, via which the fresh charge is introduced into the cylinder by means of a crankcase pump, and to a two-cycle - Internal combustion engine to carry out the process.
  • a two-stroke internal combustion engine in which the method mentioned at the outset is used, is known from US Pat. No. 4,253,433.
  • This internal combustion engine has two groups of overflow channels, which connect the crankcase designed as a crankcase pump to the cylinder.
  • An inlet, through which the internal combustion engine is supplied with the fuel-air mixture, is connected directly to an overflow channel opposite the outlet channel, the opening of the inlet in this approximately midway between the inlet slot of the overflow channel in the cylinder and its opening into the Crankcase is done.
  • Another inlet, through which air is supplied to the internal combustion engine opens into the crankcase.
  • Two further overflow channels are located on both sides of a plane containing the cylinder axis and intersecting the first overflow channel and the outlet channel in the middle.
  • a two-stroke internal combustion engine in which between the outlet channel and the inlet slots of overflow channels designed as storage spaces, which lead to a rich mixture, inlet slots of further overflow channels are arranged, which introduce a lean mixture, the lean mixture being Purge gas acts.
  • the piston moves down, as a result of which the lean fuel-air mixture is pre-compressed and enters the overflow channels and the storage spaces previously filled with the rich fuel-air mixture.
  • a lean fuel-air mixture flows from the overflow channels and a rich mixture flows into the cylinder from the storage spaces.
  • the lean mixture purges the residual gases from the cylinder, while the rich mixture from the storage spaces mixes with the lean mixture, so that an ignitable fuel-air mixture is formed. Because the inlet slots of the overflow channels lie between the inlet slots of the storage spaces and the outlet channel, a rich mixture cannot get into the outlet channel and be lost for combustion.
  • a disadvantage of this internal combustion engine is the considerable design effort, given by an additional auxiliary carburetor, or by at least one separate air inlet.
  • the object of the present invention is to provide a method for changing the charge in two-stroke internal combustion engines, which can be used with structurally simple, inexpensive precautions and guarantees good washing results, an improvement in terms of low-pollutant and more economical operation compared to conventional two-stroke internal combustion engines being achieved.
  • This object is achieved in that when the piston moves downward, the inlet slots of at least two first overflow channels, which are adjacent to the outlet channel on both sides, are opened at a time when the pressure in the cylinder is still higher than in the crankcase, so that exhaust gas flows into these overflow channels and pushes the fresh charge back into it without penetrating into the crankcase itself, and that as a result the inlet slots overflow at least two second ones channels are released, which are also arranged on both sides of the outlet channel and are further away from it than the first overflow channels, whereby the cylinder is flushed and filled with fresh charge, with the previously introduced exhaust gas emerging from the first overflow channels because of reversal of the pressure conditions and forms a barrier against the overflow of fresh charge.
  • the method according to the invention can be used particularly advantageously if, at the same time as the second overflow channels, at least one third overflow channel which opens at the wall of the cylinder opposite the outlet slot is opened or closed. This enables particularly good purging results to be achieved, in particular when using two or three channels, the gas kinetics being able to be influenced in a favorable manner in particular by freely selecting the inflow angles.
  • a two-stroke internal combustion engine for practicing the method according to the invention consists in that the upper edge of the inlet slots of at least two first overflow ducts, which are adjacent to the outlet duct and lie on both sides of a plane containing the cylinder axis through the middle of the outlet duct or the outlet duct parts, is higher than the upper edge of the inlet slots of at least two second overflow channels, which are each arranged next to the first overflow channels, whereby Exhaust gas reaches the first overflow channels, and that these first overflow channels have dimensions and / or control devices such that penetration of the exhaust gases into the crankcase is prevented.
  • An advantageous variant of a two-stroke internal combustion engine for carrying out the method according to the invention is given in that the control edge of the piston is lower in the area of the first overflow channels, which are adjacent to the outlet channel, than in the area of the second overflow channels, which are each adjacent to the first, so that Exhaust gas reaches the first overflow channels and that these first overflow channels have dimensions and / or control devices such that penetration of the exhaust gases into the crankcase is prevented.
  • This provides a second option for filling the first overflow channels with exhaust gas.
  • overflow of the exhaust gases into the crankcase must be prevented, either by certain dimensions, the length and the cross section of the first overflow channels having to be matched to the dimensions of the cylinder, or by control devices in these channels.
  • a control device preventing the penetration of exhaust gases into the crankcase is formed by the crank web, which for this purpose has a recess which interacts with the confluence of each first overflow channel in the crankcase. The purpose of this is to prevent the exhaust gases returning into the first channels from penetrating too quickly or too far in the direction of the crankcase and still to achieve an adequate filling of the channels with exhaust gas before the purging begins.
  • the two-stroke internal combustion engine shown in FIGS. 1 to 12 has a cylinder 1 with a cylinder head 2 and a crankcase 3 with a crankshaft 4.
  • the piston 6, which is connected to the crankshaft 4 via the connecting rod 5, moves in the cylinder head 2 intended.
  • the cylinder 1 is connected to the crankcase 3 via a group of first overflow channels 8, a group of second overflow channels 9 and a group of third overflow channels 10, the group of first overflow channels 8 inlet slots 12, the group of second overflow channels 9 inlet slots 13 and the group of third overflow channels 10 has inlet slots 14 in the cylinder 1.
  • the group of the first and the second overflow channels 8 and 9 each comprise two channels on both sides of a plane E containing the cylinder axis 15 and intersecting the outlet channel 16 in the middle. Both groups can, however, also have several channels on both sides of this plane E.
  • the control edge 11 of the piston 6 has a depression.
  • the group of the third overflow channels 10 also has two channels with inlet slots 14 which are diametrically opposite the outlet channel 16 with the outlet slot 17. However, this group can also have only one or more than two channels 10.
  • the first overflow channels 8 have a common opening 18 in the crankcase 3.
  • the opening of the second overflow channels 9 in the crankcase is denoted by 19.
  • the charge change takes place according to the method described with reference to FIGS. 1 to 12.
  • the inlet slits 12, 13, 14 and the outlet slit 17 are not yet moved by the downwardly moving piston 6 or by its control edge 11, which has a lowering in the region 11 ' released and cylinder 1 is filled with exhaust gas.
  • the crankshaft 4 rotates according to the direction of rotation indicated by the arrow 28.
  • phase 2 of the process sequence (FIGS. 4 to 6) the piston 6 has moved further downward and now gives both the outlet slot 17 of the outlet channel 16 and the inlet slots 12 of the first overflow channels 8 through a control edge of the piston which is lowered in the region 11 ' 6 free.
  • These channels thus open earlier than the second overflow channels 9 and so early that the cylinder pressure is still higher than the purge pressure in the crankcase 3 and the channels 8, so that exhaust gas strikes back in the upper part 21 of these channels and the fresh charge in the lower part 22 repressed.
  • the overflow channels 8 are so long that penetration of the exhaust gases into the crankcase 3 is avoided with certainty.
  • the expansion of the exhaust gases along the arrows 29 and 30 in FIGS. 4 and 5 can be clearly seen.
  • the upper parts 21 of the overflow channels 8 filled with exhaust gas can also be seen from FIG. 6.
  • phase 3 of the process sequence in which the piston 6 is at its bottom dead center, the overflow channels 9 and approximately at the same time the overflow channels 10 present here in order to achieve a better washing result and flush the cylinder 1 with them Fresh load.
  • the direction of flow reverses according to arrow 31 in FIG. 7 or 32 in FIG. 8 in channel 8 due to the pressure drop in cylinder 1, and the exhaust gas now emerging in the cylinder acts as a barrier (sealing gas) for the fresh charge flow from the channels 9 and 10. In this way the short-circuit loss of fresh charge is prevented directly into the outlet channel 16. Only towards the end of the rinsing phase does fresh charge emerge from the overflow channels 8.
  • the cylinder 1 At the end of the rinse in phase 4 of the procedure Running (Fig. 10 to 12), the cylinder 1 is ideally filled with fresh charge, without a part of it being lost in the outlet channel 16. As a result, the fresh charge with which the cylinder 1 is now completely filled (see FIGS. 11 and 12) is compressed by the piston 6 moving upward.
  • Different control times for the group of the first overflow channels 8 and the group of the second overflow channels 9 can also be achieved in that the upper edges 12 'of the inlet slots 12 of the channels 8 are higher than the upper edges 13' of the inlet slots 13 of the channels 9, the Control edge 11 of the piston 6 does not have a lowered area 11 ', or by a combination of different high top edges 12', 13 'with lowered areas 11'.
  • FIG. 13 to 17 show a variant of the two-stroke internal combustion engine specified at the outset, which differs from the first-mentioned embodiment in that a control device 20 for the first overflow channels 8 is present.
  • This control device 20, consisting of separate openings 33 of the channels 8 in the crankcase 3 and a respective cooperating recess 27 on the circumference of each crank web 26, prevents the exhaust gases from penetrating into the crankcase 3.
  • phase 1 of the process sequence (FIGS. 13 and 14) all the inlet slots 12, 13, 14 and the outlet slot 17 and the opening 33 in the crankcase 3 are closed and the cylinder 1 is filled with the exhaust gas.
  • 15 to 17 show the phases 3 to 4 of the process sequence, which come about by rotating the crankshaft 4 according to arrow 28 and are identical to FIGS. 5, 8 and 11 of the first-mentioned example with regard to the piston position and the gas exchange.
  • overflow channels 9 are also cleared, so that fresh charge penetrates cylinder 1.
  • exhaust gas acting as sealing gas passes through the overflow channel 8 according to arrow 32 into the cylinder 1 and prevents the fresh charge from flowing out into the outlet channel 16.
  • the overflow channels 8 Towards the end of the charging process, the overflow channels 8 also pass through Fresh charge in cylinder 1.
  • Phase 4 of the process sequence shows the internal combustion engine after the charge has been changed.
  • the control device 20 effectively prevents the exhaust gas front from penetrating into the crankcase 3, as a result of which there is more freedom in coordinating the dimensions of the overflow channels 8.
  • the overflow ducts and the outlet duct are controlled in the following chronological sequence: the opening start ⁇ o of the outlet duct is before the opening beginning ⁇ 1 of the overflow ducts 8, followed by the opening beginning ⁇ 2,3 of the overflow ducts 9 and 10, which have the shortest opening duration D 2,3 and close first. Then the channels 8, which have an average opening time D 1 and finally the outlet channel with the opening time D 0, close.
  • the opening start ⁇ 4 of the control device 20 lies between the opening start ⁇ 0 of the outlet channel 16 and the bottom dead center (UT) of the piston, the opening end ⁇ 5 approximately between the bottom dead center of the piston and the outlet end.

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Combustion Methods Of Internal-Combustion Engines (AREA)
  • Lubrication Details And Ventilation Of Internal Combustion Engines (AREA)
  • Electrical Control Of Air Or Fuel Supplied To Internal-Combustion Engine (AREA)
  • Exhaust-Gas Circulating Devices (AREA)
  • Cylinder Crankcases Of Internal Combustion Engines (AREA)
EP19860890118 1985-05-10 1986-04-28 Procédé pour balayer un moteur à deux temps à balayage à flux inversé et moteur fonctionnant selon ce procédé Expired EP0202216B1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
AT141985A AT399913B (de) 1985-05-10 1985-05-10 Zweitakt-brennkraftmaschine mit umkehrspülung
AT1419/85 1985-05-10

Publications (3)

Publication Number Publication Date
EP0202216A2 true EP0202216A2 (fr) 1986-11-20
EP0202216A3 EP0202216A3 (en) 1987-03-04
EP0202216B1 EP0202216B1 (fr) 1989-08-30

Family

ID=3513489

Family Applications (1)

Application Number Title Priority Date Filing Date
EP19860890118 Expired EP0202216B1 (fr) 1985-05-10 1986-04-28 Procédé pour balayer un moteur à deux temps à balayage à flux inversé et moteur fonctionnant selon ce procédé

Country Status (6)

Country Link
EP (1) EP0202216B1 (fr)
JP (1) JPS6217315A (fr)
CN (1) CN1007443B (fr)
AT (1) AT399913B (fr)
DE (1) DE3665349D1 (fr)
IN (1) IN166656B (fr)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1990008884A1 (fr) * 1989-01-24 1990-08-09 Renzo Dellarosa Ensemble de cylindre et de piston ameliore pour moteur a combustion interne a deux temps
FR2693507A1 (fr) * 1992-07-09 1994-01-14 Aura Procédé et dispositif d'alimentation d'un cylindre de moteur à combustion interne à deux temps.

Families Citing this family (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6729275B2 (en) 1999-02-05 2004-05-04 Avl List Gmbh Two-stroke internal combustion engine with crankcase scavenging
US6539900B2 (en) 1999-02-05 2003-04-01 Avl List Gmbh Two-stroke internal combustion engine with crankcase scavenging
DE10319216B4 (de) * 2003-04-29 2015-09-24 Andreas Stihl Ag & Co. Kg Zweitaktmotor
FR2864578B1 (fr) * 2003-12-31 2006-03-24 Magneti Marelli Motopropulsion Moteur deux temps a injection directe
CN103790690B (zh) * 2014-02-21 2017-03-08 浙江天泰机械有限公司 一种汽油机
CN107366573A (zh) * 2017-07-04 2017-11-21 贵州宝文电机科技有限公司 转缸发动机
CN107524514B (zh) * 2017-07-25 2019-07-23 北京航空航天大学 一种两冲程高功重比重油活塞发动机进气缓冲器及其设计方法
CN112696265A (zh) * 2020-12-24 2021-04-23 南通理工学院 一种减少环境污染的二冲程内燃机

Family Cites Families (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
AT138547B (de) * 1933-06-02 1934-08-10 Karl Letzner Zweitakt-Brennkraftmaschine.
FR759044A (fr) * 1933-07-31 1934-01-27 Moteur à deux temps à combustion interne
GB464750A (en) * 1935-10-14 1937-04-23 Messerschmitt Boelkow Blohm Improvements in and relating to the scavenging and charging of the cylinders of two-stroke internal combustion engines
FR1022403A (fr) * 1949-07-06 1953-03-04 Miller & Company Ltd H Perfectionnements aux moteurs à combustion interne
DE849624C (de) * 1949-11-01 1952-09-18 Gertrud Schnuerle Zweitakt-Brennkraftmaschine mit Vergaser und Zuendkerze
DE1008046B (de) * 1953-01-10 1957-05-09 Kloeckner Humboldt Deutz Ag Mit kleinem Zeitquerschnitt fuer den Vorauslass der Abgase arbeitende Zweitaktbrennkraftmaschine
DE1010315B (de) * 1955-05-28 1957-06-13 Otto Elwert Dipl Ing Kolbengesteuerte Zweitakt-Brennkraftmaschine
GB1345707A (en) * 1970-05-21 1974-02-06 Glen J R Two-stroke internal combustion engines
DE2151941A1 (de) * 1971-10-19 1973-04-26 Blume Geb Schroedet Helga Gemischspuelung mit spuelvorlage
US3815558A (en) * 1972-08-07 1974-06-11 W Tenney Scavenge porting system
DE2650834A1 (de) * 1975-12-22 1977-06-30 Thaelmann Fahrzeug Jagdwaffen Gemischgespuelte zweitakt-brennkraftmaschine
DE2919172A1 (de) * 1977-08-25 1979-11-15 Univ Belfast Zweitakt-brennkraftmaschine
FR2425543B1 (fr) * 1978-05-12 1986-02-07 Univ Belfast Moteur a combustion interne a deux temps
GB2083550B (en) * 1980-08-29 1984-05-16 Outboard Marine Corp Scavening two-stroke internal combustion engines
GB2115485B (en) * 1982-02-17 1987-01-07 Nat Res Dev Stratified charge engines
JPS59134323A (ja) * 1983-01-19 1984-08-02 Nippon Clean Engine Res 時間差衝突層状掃気２サイクル機関
JPS6040727A (ja) * 1983-08-13 1985-03-04 Nippon Clean Engine Res 層状掃気二サイクル内燃機関

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1990008884A1 (fr) * 1989-01-24 1990-08-09 Renzo Dellarosa Ensemble de cylindre et de piston ameliore pour moteur a combustion interne a deux temps
FR2693507A1 (fr) * 1992-07-09 1994-01-14 Aura Procédé et dispositif d'alimentation d'un cylindre de moteur à combustion interne à deux temps.
WO1994001663A1 (fr) * 1992-07-09 1994-01-20 Aura - Association Universitaire De Recherche Appliquée Procede et dispositif d'alimentation d'un cylindre de moteur a combustion interne a deux temps

Also Published As

Publication number Publication date
JPS6217315A (ja) 1987-01-26
ATA141985A (de) 1994-12-15
CN86103240A (zh) 1986-11-05
DE3665349D1 (en) 1989-10-05
IN166656B (fr) 1990-06-30
EP0202216B1 (fr) 1989-08-30
AT399913B (de) 1995-08-25
CN1007443B (zh) 1990-04-04
JPH0246772B2 (fr) 1990-10-17
EP0202216A3 (en) 1987-03-04

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