EP0217374A1 - Piston-cylinder unit for a two-stroke internal combustion engine - Google Patents

Piston-cylinder unit for a two-stroke internal combustion engine Download PDF

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Publication number
EP0217374A1
EP0217374A1 EP86113495A EP86113495A EP0217374A1 EP 0217374 A1 EP0217374 A1 EP 0217374A1 EP 86113495 A EP86113495 A EP 86113495A EP 86113495 A EP86113495 A EP 86113495A EP 0217374 A1 EP0217374 A1 EP 0217374A1
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EP
European Patent Office
Prior art keywords
piston
cylinder
cavities
casing
group according
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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
EP86113495A
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German (de)
French (fr)
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EP0217374B1 (en
Inventor
Umberto Panzeri
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Dott Vittorio Gilardoni SpA
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Dott Vittorio Gilardoni SpA
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Priority to AT86113495T priority Critical patent/ATE50318T1/en
Publication of EP0217374A1 publication Critical patent/EP0217374A1/en
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    • 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
    • F02B25/14—Engines characterised by using fresh charge for scavenging cylinders using reverse-flow scavenging, e.g. with both outlet and inlet ports arranged near bottom of piston stroke
    • 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
    • F02B75/00—Other engines
    • F02B75/02—Engines characterised by their cycles, e.g. six-stroke
    • F02B2075/022—Engines characterised by their cycles, e.g. six-stroke having less than six strokes per cycle
    • F02B2075/025—Engines characterised by their cycles, e.g. six-stroke having less than six strokes per cycle two

Definitions

  • the invention relates to two-stroke internal combustion engines and relates to a method for increasing the performance of said engines while keeping an unchanged displacement and without making any modification to the casing.
  • the method according to the invention can be applied to two-stroke engines with suction of the usual type, with lamellar suction in the casing and / or in the cylinder, with suction with rolling valve, or with suction regulated by any device.
  • the invention also includes a piston-cylinder group for two-stroke internal combustion engines.
  • the fresh gases coming from the casing undergo abrupt deviations from the fact that they must pass from a substantially axial direction, when they are pushed towards the inside of the piston, to a radial direction, when they pass through the small windows formed in the envelope of the piston, and then again in an axial direction when they flow along said cavities and finally again in a substantially radial direction when they reach the upper end of the cavities and are sent to the explosion chamber.
  • One of the objects of the present invention is therefore to propose a method for improving the scanning conditions of the cylinder of a two-stroke engine which does not impose the need to modify the crankcase of the engine itself and which does not have the disadvantages of the known method mentioned above.
  • Said goal is achieved by practicing in correspondence dance of the piston-cylinder separation surface, one or more cavities able to put the interior of the housing in direct communication with the explosion chamber when the piston is near its bottom dead center.
  • the invention comprises a piston-cylinder group, characterized in that the piston-cylinder separation surface has one or more cavities which directly connect the interior of the casing with the explosion chamber for positions of the piston located near its bottom dead center.
  • Said cavity or cavities are preferably arranged longitudinally, opposite the exhaust port and laterally to the windows of the main supply passages.
  • the upper end of said one or more cavities is substantially at the right of the upper edge of the windows of the main passages and said proximity of the lower dead center in the movement of the piston is defined by the correspondence of the segments with said upper ends of the cavities.
  • Said cavity or cavities are formed at least in part in the cylinder liner and extend to the inside of the casing.
  • an increase in the fresh gas passage cross section results in an increase in the dead volume of the casing.
  • Said increase in the dead volume of the casing causes a decrease in the speed of passage of fresh gases through said sections and therefore a decrease in the quantity of fresh gases generally admitted into the explosion chamber.
  • the longitudinal cavities also formed in the separation surface of the piston-cylinder group according to the invention increase the dead volume of the casing.
  • a positive effect increase in the cross-section of the passage of fresh gases
  • a negative effect is introduced (increase in the dead volume of the casing).
  • the sum of these effects is undoubtedly positive, but the ideal would be to minimize the negative effect.
  • Another object of the present invention is therefore to improve the sweeping conditions of a two-stroke engine without this resulting in an increase in the dead volume of the casing.
  • the scanning conditions of the cylinder are improved while leaving the value of the crankcase dead volume substantially unchanged.
  • the creation of cavities in the external envelope of the piston necessarily resulting in a decrease in its volume in dull, causes a decrease in the dead volume of the casing.
  • the creation of cavities in the piston is accompanied by a reduction in said volume and the sum of these two effects gives as result keeping the value of the dead volume of the casing constant or decreasing it, the fresh gas passage section gained being equal.
  • the piston-cylinder group according to the invention makes it possible to improve the conditions for sweeping the cylinder while leaving the value of the dead volume of the casing unchanged or even by decreasing it.
  • the piston-cylinder group according to the invention makes it possible to increase the performance of two-stroke engines without this resulting in the need to modify the crankcase of the engine itself. Indeed, to increase engine performance, simply replace the original piston-cylinder group with the group produced according to the in vention.
  • the cylinder 1 illustrated is intended for an air-cooled engine with lamellar suction in the casing.
  • Said cylinder 1 comprises a plurality of cooling fins 2, a jacket 3, a series of axial holes 4 for the passage of the engine cylinder mounting screws, a main exhaust duct 5, with two secondary exhaust ducts 5 'next to it, and a couple of main passages 6 opening into the jacket 3 through windows 8.
  • a longitudinal cavity 7 is formed in a manner known per se, on the side opposite to the main exhaust duct 5 and in central position relative to the windows 8 of the main passages.
  • Said cavity extends downward from a point substantially aligned with the upper edge of the windows 8 of the main passages to a point located below the piston top but above the lower edge of the piston jacket when the latter is at its bottom dead center.
  • the cavity 7 is therefore not directly connected to the casing but, as will be explained below, its only function is to send part of the fresh gases into the explosion chamber which will fill the internal volume of the piston from the housing.
  • the piston 11 illustrated comprises a casing 12, a top 13, a seat 14 for housing a sealing segment, a radial passage hole 15 for housing the ends of an axis of piston.
  • a small window 16 has been made, in known manner, intended to align with the cavity 7 formed in the jacket 3 of the cylinder 1. Through the small window 16, when the piston located near its bottom dead center, part of the fresh gas passes from the interior of the piston itself to the cavity 7 and from the latter to the explosion chamber.
  • the casing 12 of the piston has a pair of longitudinal cavities 17 extending from the lower edge 18 of the casing to the underside of the seat 14 for housing the prop segment cheerfulness.
  • FIG. 6, illustrating the piston 11 inserted in the cylinder 1, shows how the cavities 17 formed in the casing of the piston align with the longitudinal cavities 9 formed in the jacket 3 of the cylinder 1 by creating conduits 19. From this so, when the piston is near its lower dead center, a part of the fresh gases present in the crankcase of the engine rises through the conduits 19 created by the alignment of the longitudinal cavities 9 and 17 formed respectively in the jacket 3 and in the casing 11 of the piston. When the sealing segment of the piston 11 passes below the upper end of the cavities 9, the fresh gases present in the conduits 19 penetrate into the explosion chamber, adding to the fresh gases which flow from the cavity 7 and windows 8 of the main passages.
  • the fresh gases leaving the cavities 19, having an upwardly directed movement component contribute to directing upwards the fresh gases leaving the windows 8 of the main passages, by increasing the length of their course so that the piston has time to close the exhaust port before they can flow through said port.
  • FIG. 7 shows the linear development of a cylinder according to the invention intended for an engine with four main passages and with the suction in the casing controlled by lamellae.
  • FIG. 10 illustrates a cross section made at the right of the windows of the main passages of the cylinder of FIG. 7 in combination with the piston according to the invention.
  • the method according to the invention can be applied to two-stroke engines with lamellar aspiration in the cylinder, with rolling valve or with any other suction control device.
  • the method according to the invention is applied to two-stroke engines with the suction duct formed in the cylinder and controlled by strips.
  • the cylinder 26 has four windows 27 of the main passages, an exhaust duct 28, and a suction duct 29.
  • three longitudinal cavities have also been made, including the central cavity 30 n ' is not connected to the housing and the lateral cavities 31 are in communication with the housing.
  • FIG. 11 which is a section made in line with the windows of the main passages of the cylinder of FIG. 8, in combination with the piston according to the invention, the cavities 31 on the cylinder liner and the cavities 32 on the casing of the piston 33 form conduits 34 connected to the casing.
  • Said conduits 34 in addition to their function of additional passages, also have the function of additional conduits for supplying fresh gas to the casing.
  • Figure 9 shows a cylinder substantially similar to the cylinder illustrated in Figure 8, except that the three longitudinal cavities 35 formed in the jacket are in communication with the housing.
  • Figure 12 is a section taken on the central line of the suction duct of the cylinder of Figure 9 in combination with the piston according to the invention.
  • FIG. 13 shows a detail of the piston-cylinder separation surface of another possible embodiment according to the invention.
  • the reference 36 indicates the cylinder liner and 37 is a longitudinal cavity formed in the liner itself.
  • the upper edge of said cavity is substantially in line with the upper edges of the windows of the main passages, while the lower edge is located near the lower dead center of the piston.
  • Said cavity 37 is not in communication with the casing.
  • the envelope of the piston 38 shows a longitudinal cavity 39, quite similar to the cavities formed in the piston illustrated in FIGS. 4 and 5, which aligns with the cavity 37 formed in the envelope.

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Cylinder Crankcases Of Internal Combustion Engines (AREA)
  • Combustion Methods Of Internal-Combustion Engines (AREA)
  • Pistons, Piston Rings, And Cylinders (AREA)
  • Lubrication Of Internal Combustion Engines (AREA)
  • Valve Device For Special Equipments (AREA)

Abstract

1. A piston-cylinder assembly for a two cycle internal combustion engine, having first recesses or grooves (9, 20, 31) longitudinally extending in the cylinder liner (3, 21, 36) and directly connecting the inner portion of motor crankcase with the motor combustion chamber when said piston (11) is in positions near its bottom dead center, characterized in that said first grooves cooperate with second grooves or recesses (17, 23, 32, 39) longitudinally extending in the piston liner (12, 24, 33, 38), in correspondence with the cylinder grooves, so as to conjointly form ducts or passages (19, 25, 34) which are adapted to ensure a sweeping of the motor combustion chamber, without involving any main gas feeding passage, said second grooves (17, 23, 32, 39) extending from the lower edge of said piston liner up to a position below the piston seats (14) for seating the piston rings.

Description

L'invention est relative aux moteurs à combustion interne à deux temps et concerne un procédé pour augmenter les performances desdits moteurs tout en gardant une cylindrée inchangée et sans apporter aucune modification au carter.The invention relates to two-stroke internal combustion engines and relates to a method for increasing the performance of said engines while keeping an unchanged displacement and without making any modification to the casing.

Le procédé selon l'invention peut être appliqué aux moteurs à deux temps avec aspiration du type usuel, avec aspiration lamellaire dans le carter et/ou dans le cylindre, avec aspiration à soupape roulante, ou avec aspiration réglée par un dispositif quelconque.The method according to the invention can be applied to two-stroke engines with suction of the usual type, with lamellar suction in the casing and / or in the cylinder, with suction with rolling valve, or with suction regulated by any device.

L'invention comprend également un groupe piston-cylindre pour moteurs à combustion interne à deux temps.The invention also includes a piston-cylinder group for two-stroke internal combustion engines.

On sait que pour augmenter les performances des moteurs à deux temps sans en accroître la cylindrée, il faut améliorer les conditions de balayage du cylindre en augmentant la section globale de passage des gaz frais. Ladite augmentation de section peut être obtenue en élargissant les lumières d'admission et/ou en augmentant si possible leur nombre.It is known that in order to increase the performance of two-stroke engines without increasing the cubic capacity, it is necessary to improve the scanning conditions of the cylinder by increasing the overall cross-section of the fresh gases. Said increase in section can be obtained by widening the intake ports and / or by increasing their number if possible.

Toutefois, dans les cas où l'on désire améliorer les conditions de balayage du cylindre d'un moteur déjà en production, il n'est pas possible de pratiquer de nouvelles lumières d'admission sans modifier aussi le carter du moteur.However, in cases where it is desired to improve the scanning conditions of the cylinder of an engine already in production, it is not possible to practice new intake lights without also modifying the engine casing.

Dans ce cas, et toujours dans le but d'augmenter la section globale de passage des gaz frais, on a proposé de pratiquer des cavités longitudinales dans le cylindre, essentiellement disposées entre le point mort supérieur et le point mort inférieur du piston, en face de la lumière d'échappement. Lesdites cavités sont alignées avec de petites fenêtres correspondantes pratiquées dans l'enveloppe du piston. De cette façon, pendant la course descendante du piston, une partie des gaz frais qui depuis le carter tendent à remplir le volume interne du piston, passe à travers les petites fenêtres pratiquées dans l'enveloppe du piston, s'écoulent dans lesdites cavités et, de ces dernières, passe ensuite dans la chambre d'explosion. Ce procédé connu, tout en permettant d'améliorer les conditions de balayage du cylindre et d'augmenter les prestations du moteur, présente quelques inconvénients.In this case, and still with the aim of increasing the overall cross-section of the passage of fresh gases, it has been proposed to make longitudinal cavities in the cylinder, essentially arranged between the upper dead center and the lower dead center of the piston, opposite of the exhaust light. Said cavities are aligned with corresponding small windows formed in the udder envelope your. In this way, during the downward stroke of the piston, part of the fresh gases which from the casing tend to fill the internal volume of the piston, passes through the small windows made in the casing of the piston, flow into said cavities and , of the latter, then passes into the explosion chamber. This known method, while making it possible to improve the scanning conditions of the cylinder and to increase the performance of the engine, has some drawbacks.

En effet, les gaz frais provenant du carter subissent de brusques déviations du fait qu'ils doivent passer d'une direction substantiellement axiale, lorsqu'ils sont poussés vers l'intérieur du piston, à une direction radiale, lorsqu'ils passent à travers les petites fenêtres pratiquées dans l'enveloppe du piston, et puis encore à une direction axiale lorsqu'ils s'écoulent le long desdites cavités et enfin de nouveau à une direction substantiellement radiale lorsqu'ils atteignent l'extrémité supérieure des cavités et la sont envoyés dans la chambre d'explosion.Indeed, the fresh gases coming from the casing undergo abrupt deviations from the fact that they must pass from a substantially axial direction, when they are pushed towards the inside of the piston, to a radial direction, when they pass through the small windows formed in the envelope of the piston, and then again in an axial direction when they flow along said cavities and finally again in a substantially radial direction when they reach the upper end of the cavities and are sent to the explosion chamber.

Lesdites déviations brusques entraînent des pertes de charge qui ne permettent pas d'exploiter au maximum les avantages que l'augmentation de la section de passage des gaz frais devrait entraîner.Said abrupt deviations result in pressure drops which do not allow the advantages which the increase in the cross-section of the fresh gases to pass to be exploited to the maximum.

Un des objets de la présente invention est donc de proposer-un procédé pour améliorer les conditions de balayage du cylindre d'un moteur à deux temps qui n'impose pas la nécessité de modifier le carter du moteur lui-même et qui ne présente pas les inconvénients du procédé connu mentionné plus haut.One of the objects of the present invention is therefore to propose a method for improving the scanning conditions of the cylinder of a two-stroke engine which does not impose the need to modify the crankcase of the engine itself and which does not have the disadvantages of the known method mentioned above.

Ledit but est atteint en pratiquant en correspondance de la surface de séparation piston-cylindre, une ou plusieurs cavités aptes à mettre en communication directe l'intérieur du carter avec la chambre d'explosion lorsque le piston se trouve à proximité de son point mort inférieur.Said goal is achieved by practicing in correspondence dance of the piston-cylinder separation surface, one or more cavities able to put the interior of the housing in direct communication with the explosion chamber when the piston is near its bottom dead center.

De cette façon, les gaz frais passent directement du carter à l'intérieur de la chambre d'explosion, s'écoulent le long desdites cavités et subissent donc une seule déviation lorsqu'ils arrivent en correspondance de l'extrémité supérieure des cavités elles-mêmes.In this way, the fresh gases pass directly from the casing inside the explosion chamber, flow along said cavities and therefore undergo a single deflection when they arrive in correspondence from the upper end of the cavities themselves. same.

Pour la réalisation dudit procédé, l'invention comprend un groupe piston-cylindre, caractérisé en ce que la surface de séparation piston-cylindre présente une ou plusieurs cavités qui relient directement l'intérieur du carter avec la chambre d'explosion pour des positions du piston situées à proximité de son point mort inférieur.For carrying out said method, the invention comprises a piston-cylinder group, characterized in that the piston-cylinder separation surface has one or more cavities which directly connect the interior of the casing with the explosion chamber for positions of the piston located near its bottom dead center.

Ladite ou lesdites cavités sont de préférence disposées longitudinalement, en face de la lumière d'échappement et latéralement aux fenêtres des passages d'alimentation principaux. L'extrémité supérieure de ladite ou desdites cavités est sensiblement au droit du bord supérieur des fenêtres des passages principaux et ladite proximité du point mort inférieur dans le mouvement du piston est définie par la correspondance des segments avec lesdites extrémités supérieures des cavités.Said cavity or cavities are preferably arranged longitudinally, opposite the exhaust port and laterally to the windows of the main supply passages. The upper end of said one or more cavities is substantially at the right of the upper edge of the windows of the main passages and said proximity of the lower dead center in the movement of the piston is defined by the correspondence of the segments with said upper ends of the cavities.

Ladite ou lesdites cavités sont pratiquées au moins en partie dans la chemise du cylindre et s'étendent jusqu'à l'intérieur du carter.Said cavity or cavities are formed at least in part in the cylinder liner and extend to the inside of the casing.

Comme on le sait, une augmentation de la section de passage des gaz frais entraîne une augmentation du volume mort du carter. Ladite augmentation du volume mort du carter cause une diminution de la vitesse de passage des gaz frais à travers lesdites sections et donc une diminution de la quantité des gaz frais globalement admis dans la chambre d'explosion.As is known, an increase in the fresh gas passage cross section results in an increase in the dead volume of the casing. Said increase in the dead volume of the casing causes a decrease in the speed of passage of fresh gases through said sections and therefore a decrease in the quantity of fresh gases generally admitted into the explosion chamber.

Les cavités longitudinales aussi pratiquées dans la surface de séparation du groupe piston-cylindre selon l'invention augmentent le volume mort du carter. Au moyen desdites cavités l'on obtient donc un effet positif (augmentation de la section de passage des gaz frais), mais en même temps on introduit un effet négatif (augmentation du volume mort du carter). La somme desdits effets est sans doute positive, mais l'idéal serait de réduire au maximum l'effet négatif.The longitudinal cavities also formed in the separation surface of the piston-cylinder group according to the invention increase the dead volume of the casing. By means of said cavities there is therefore obtained a positive effect (increase in the cross-section of the passage of fresh gases), but at the same time a negative effect is introduced (increase in the dead volume of the casing). The sum of these effects is undoubtedly positive, but the ideal would be to minimize the negative effect.

Un autre objet de la présente invention est donc d'améliorer les conditions de balayage d'un moteur à deux temps sans que cela entraîne une augmentation du volume mort du carter.Another object of the present invention is therefore to improve the sweeping conditions of a two-stroke engine without this resulting in an increase in the dead volume of the casing.

Ledit objet est atteint en pratiquant dans l'enveloppe du piston du groupe piston-cylindre selon l'invention, une ou plusieurs cavités s'étendant de son bord inférieur jusqu'au dessous du siège de logement du segment d'étanchéité, lesdites cavités s'alignant avec les cavités pratiquées dans la chemise du cylindre et communiquant avec le carter du moteur.Said object is achieved by practicing in the piston envelope of the piston-cylinder group according to the invention, one or more cavities extending from its lower edge to the underside of the seat for housing the sealing segment, said cavities s '' aligning with the cavities in the cylinder liner and communicating with the motor housing.

De cette façon, les conditions de balayage du cylindre sont améliorées tout en laissant substantiellement inchangée la valeur du volume mort du carter. En effet, comme l'intérieur du piston doit être considéré volume mort, la création de cavités dans l'enveloppe externe du piston, entraînant nécessairement une diminution de son volume interne, provoque une diminution du volume mort du carter. Alors, si la création de cavités dans la chemise du cylindre s'accompagne d'un accroissement du volume mort du carter, la création de cavités dans le piston s'accompagne d'une diminution dudit volume et la somme de ces deux effets donne comme résultat le fait de maintenir la valeur du volume mort du carter constante ou bien de la diminuer, la section de passage des gaz frais gagnée étant égale.In this way, the scanning conditions of the cylinder are improved while leaving the value of the crankcase dead volume substantially unchanged. Indeed, as the interior of the piston must be considered dead volume, the creation of cavities in the external envelope of the piston, necessarily resulting in a decrease in its volume in dull, causes a decrease in the dead volume of the casing. So, if the creation of cavities in the cylinder liner is accompanied by an increase in the dead volume of the casing, the creation of cavities in the piston is accompanied by a reduction in said volume and the sum of these two effects gives as result keeping the value of the dead volume of the casing constant or decreasing it, the fresh gas passage section gained being equal.

En conclusion, le groupe piston-cylindre selon l'invention permet d'améliorer les conditions de balayage du cylindre tout en laissant la valeur du volume mort du carter inchangée ou même en la diminuant.In conclusion, the piston-cylinder group according to the invention makes it possible to improve the conditions for sweeping the cylinder while leaving the value of the dead volume of the casing unchanged or even by decreasing it.

En particulier, dans le cas où le procédé selon l'invention est appliqué à un moteur avec aspiration directement contrôlée par lamelles dans le cylindre, outre l'amélioration des conditions de lavage du cylindre, on obtient aussi une meilleure aspiration. En effet, pendant la course ascendante du piston, lorsque le piston a lui-même fermé les fenêtres des passages dans le cylindre et commence à développer la fonction de pompe aspirante des gaz frais dans lP carter, les cavités pratiquées dans la surface de séparation pigeon- cylindre et communiquant avec le carter mettent en communication constante le conduit d'aspiration, pratiqué dans le cylindre et réglé par les lamelles, avec le carter lui-même.In particular, in the case where the method according to the invention is applied to an engine with suction directly controlled by blades in the cylinder, in addition to improving the washing conditions of the cylinder, better suction is also obtained. Indeed, during the upward stroke of the piston, when the piston itself has closed the windows of the passages in the cylinder and begins to develop the function of pump sucking fresh gases in the P casing, the cavities formed in the separation surface pigeon-cylinder and communicating with the housing put in constant communication the suction duct, formed in the cylinder and adjusted by the slats, with the housing itself.

Comme déjà dit ci-dessus, le groupe piston-cylindre selon l'invention permet d'accroître les performances des moteurs à deux temps sans que cela entraîne la nécessité de modifier le carter du moteur lui-même. En effet, pour accroître les performances du moteur il suffit de remplacer le groupe piston-cylindre d'origine par le groupe réalisé selon l'invention.As already mentioned above, the piston-cylinder group according to the invention makes it possible to increase the performance of two-stroke engines without this resulting in the need to modify the crankcase of the engine itself. Indeed, to increase engine performance, simply replace the original piston-cylinder group with the group produced according to the in vention.

Après des essais appropriés, on a constaté que la création de cavités dans l'enveloppe du piston, tout en déterminant une diminution de la surface utile de contact entre l'enveloppe elle-même et la chemise du cylindre, n'entraîne aucune conséquence négative ; au contraire, lesdites cavités provoquent un effet positif de raidissement du piston.After appropriate tests, it has been found that the creation of cavities in the envelope of the piston, while determining a reduction in the useful contact area between the envelope itself and the cylinder liner, has no negative consequences. ; on the contrary, said cavities cause a positive effect of stiffening of the piston.

Ces caractéristiques et d'autres encore de l'invention seront maintenant décrites en référence aux dessins annexés dont les figures illustrent, à titre d'exemple non limitatif, des modes de réalisation différents d'un groupe piston-cylindre selon l'invention pour un moteur à deux temps monocylindrique. Sur les dessins :

  • La figure 1 est une vue en plan, du côté du carter, d'un cylindre selon l'invention pour un moteur refroidi par air et avec aspiration lamellaire dans le carter ;
  • la figure 2 est une coupe du cylindre selon la ligne A-A de la figure 1 ;
  • la figure 3 est un développement linéaire du cylindre illustré dans les figures qui précèdent ;
  • la figure 4 est une vue latérale d'un piston selon l'invention ;
  • la figure 5 est une coupe du piston selon la ligne B-B de la figure qui précède ;
  • la figure 6 est une coupe transversale d'un groupe constitué par le piston et le cylindre illustrés dans le figures qui précèdent ;
  • les figures 7, 8 et 9 sont des développements linéaires d'autres modes de réalisation possibles du cylindre selon l'invention, lesdits cylindres étant destinés à un moteur refroidi par eau, avec aspiration lamellaire dans le cylindre et avec quatre passages principaux :
  • la figure 10 est une coupe transversale au droit des fenêtres des passages principaux d'un groupe piston-cylindre selon l'invention où le cylindre est celui illustré dans la figure 7;
  • la figure 11 est une coupe transversale au droit des fenêtres des passages principaux d'un groupe piston-cylindre selon l'invention où le cylindre est celui illustré dans la figure 8 ;
  • la figure 12 est une coupe transversale selon la ligne centrale du conduit d'aspiration d'un groupe piston-cylindre selon l'invention où le cylindre est celui illustré dans la figure 9 ;
  • la figure 13 est un détail de la surface de séparation piston-cylindre d'un autre mode de réalisation possible d'un groupe piston-cylindre selon l'invention.
These and other characteristics of the invention will now be described with reference to the accompanying drawings, the figures of which illustrate, by way of non-limiting example, different embodiments of a piston-cylinder group according to the invention for a single-cylinder two-stroke engine. In the drawings:
  • Figure 1 is a plan view, on the side of the housing, of a cylinder according to the invention for an air-cooled engine with lamellar suction in the housing;
  • Figure 2 is a section of the cylinder along line AA of Figure 1;
  • Figure 3 is a linear development of the cylinder illustrated in the preceding figures;
  • Figure 4 is a side view of a piston according to the invention;
  • Figure 5 is a section of the piston along line BB of the preceding figure;
  • Figure 6 is a cross section of a group consisting of the piston and the cylinder illustrated in the preceding figures;
  • Figures 7, 8 and 9 are linear developments of other possible embodiments of the cylinder according to the invention, said cylinders being intended for an engine water-cooled, with lamellar suction in the cylinder and with four main passages:
  • Figure 10 is a cross section at right of the windows of the main passages of a piston-cylinder group according to the invention where the cylinder is that illustrated in Figure 7;
  • Figure 11 is a cross section at right of the windows of the main passages of a piston-cylinder group according to the invention where the cylinder is that illustrated in Figure 8;
  • Figure 12 is a cross section along the central line of the suction duct of a piston-cylinder group according to the invention where the cylinder is that illustrated in Figure 9;
  • FIG. 13 is a detail of the piston-cylinder separation surface of another possible embodiment of a piston-cylinder group according to the invention.

En référence aux dessins annexés et en particulier aux figures de 1 à 3, le cylindre 1 illustré est destiné à un moteur à refroidissement par air et aspiration lamellaire dans le carter. Ledit cylindre 1 comprend une pluralité d'ailettes de refroidissement 2, une chemise 3, une série de trous axiaux 4 pour le passage des vis de montage du cylindre moteur, un conduit principal d'échappement 5, avec deux conduits secondaires d'échappement 5' à côté, et un couple de passages principaux 6 débouchant dans la chemise 3 à travers des fenêtres 8. Dans la chemise 3 une cavité longitudinale 7 est pratiquée de façon en soi connue, du côté opposé au conduit principal d'échappement 5 et en position centrale par rapport aux fenêtres 8 des passages principaux. Ladite cavité s'étend vers le bas à partir d'un point sensiblement aligné avec le bord supérieur des fenêtres 8 des passages principaux jusqu'à un point placé au dessous du dessus de piston mais au dessus du bord inférieur de la chemise du piston lorsque ce dernier se trouve à son point mort inférieur. La cavité 7 n'est donc pas directement reliée au carter mais, comme on va l'expliquer ci-après, sa seule fonction est d'envoyer dans la chambre d'explosion une partie des gaz frais qui vont remplir le volume interne du piston depuis le carter. A côté de la cavité 7 sont pratiquées deux cavités longitudinales 9, lesdites cavités s'étendant vers le bas depuis un point sensiblement aligné avec le bord supérieur des fenêtres 8 des passages principaux jusqu'au bord inférieur 10 de la chemise 3 du cylindre. De cette façon, les cavités 9 sont directement reliées au carter du moteur.With reference to the appended drawings and in particular to the figures from 1 to 3, the cylinder 1 illustrated is intended for an air-cooled engine with lamellar suction in the casing. Said cylinder 1 comprises a plurality of cooling fins 2, a jacket 3, a series of axial holes 4 for the passage of the engine cylinder mounting screws, a main exhaust duct 5, with two secondary exhaust ducts 5 'next to it, and a couple of main passages 6 opening into the jacket 3 through windows 8. In the jacket 3 a longitudinal cavity 7 is formed in a manner known per se, on the side opposite to the main exhaust duct 5 and in central position relative to the windows 8 of the main passages. Said cavity extends downward from a point substantially aligned with the upper edge of the windows 8 of the main passages to a point located below the piston top but above the lower edge of the piston jacket when the latter is at its bottom dead center. The cavity 7 is therefore not directly connected to the casing but, as will be explained below, its only function is to send part of the fresh gases into the explosion chamber which will fill the internal volume of the piston from the housing. Next to the cavity 7 are formed two longitudinal cavities 9, said cavities extending downward from a point substantially aligned with the upper edge of the windows 8 of the main passages to the lower edge 10 of the jacket 3 of the cylinder. In this way, the cavities 9 are directly connected to the motor housing.

En référence aux figures 4 et 5, le piston 11 illustré comprend une enveloppe 12, un dessus 13, un siège 14 de logement d'un segment d'étanchéité, un trou radial de passage 15 pour le logement des extrémités d'un axe de piston.With reference to FIGS. 4 and 5, the piston 11 illustrated comprises a casing 12, a top 13, a seat 14 for housing a sealing segment, a radial passage hole 15 for housing the ends of an axis of piston.

Sur l'enveloppe 12 du piston on a pratiqué, de façon en soi connue, une petite fenêtre 16 destinée à s'aligner avec la cavité 7 pratiquée dans la chemise 3 du cylindre 1. A travers la petite fenêtre 16, lorsque le piston se trouve à proximité de son point mort inférieur, une partie des gaz frais passe de l'intérieur du piston lui-même à la cavité 7 et depuis cette dernière à la chambre d'explosion.On the casing 12 of the piston, a small window 16 has been made, in known manner, intended to align with the cavity 7 formed in the jacket 3 of the cylinder 1. Through the small window 16, when the piston located near its bottom dead center, part of the fresh gas passes from the interior of the piston itself to the cavity 7 and from the latter to the explosion chamber.

Latéralement à la petite fenêtre 16, l'enveloppe 12 du ,piston présente une paire de cavités longitudinales 17 s'étendant depuis le bord inférieur 18 de l'enveloppe jusqu'au dessous du siège 14 de logement du segment d'étanchéité.Laterally at the small window 16, the casing 12 of the piston has a pair of longitudinal cavities 17 extending from the lower edge 18 of the casing to the underside of the seat 14 for housing the prop segment cheerfulness.

La figure 6, illustrant le piston 11 inséré dans le cylindre 1, montre comment les cavités 17 pratiquées dans l'enveloppe du piston s'alignent avec les cavités longitudinales 9 pratiquées dans la chemise 3 du cylindre 1 en créant des conduits 19. De cette façon, lorsque le piston se trouve à proximité de son point mort inférieur, une partie des gaz frais présents dans le carter du moteur monte à travers les conduits 19 créés par l'alignement des cavités longitudinales 9 et 17 pratiquées respectivement dans la chemise 3 et dans l'enveloppe 11 du piston. Lorsque le segment d'étanchéité du piston 11 passe au dessous de l'extrémité supérieure des cavités 9, les gaz frais présents dans les conduits 19 pénètrent dans la chambre d'explosion, s'ajoutant aux gaz frais qui s'écoulent de la cavité 7 et des fenêtres 8 des passages principaux.FIG. 6, illustrating the piston 11 inserted in the cylinder 1, shows how the cavities 17 formed in the casing of the piston align with the longitudinal cavities 9 formed in the jacket 3 of the cylinder 1 by creating conduits 19. From this so, when the piston is near its lower dead center, a part of the fresh gases present in the crankcase of the engine rises through the conduits 19 created by the alignment of the longitudinal cavities 9 and 17 formed respectively in the jacket 3 and in the casing 11 of the piston. When the sealing segment of the piston 11 passes below the upper end of the cavities 9, the fresh gases present in the conduits 19 penetrate into the explosion chamber, adding to the fresh gases which flow from the cavity 7 and windows 8 of the main passages.

En particulier, les gaz frais sortant des cavités 19, ayant une composante de mouvement dirigée vers le haut, contribuent à diriger vers le haut les gaz frais sortant des fenêtres 8 des passages principaux, en augmentant la longueur de leur parcours de sorte que le piston a le temps de fermer la lumièe d'échappement avant que ceux-ci puissent s'écouler à travers ladite lumière.In particular, the fresh gases leaving the cavities 19, having an upwardly directed movement component, contribute to directing upwards the fresh gases leaving the windows 8 of the main passages, by increasing the length of their course so that the piston has time to close the exhaust port before they can flow through said port.

La figure 7 montre le développement linéaire d'un cylindre selon l'invention destiné à un moteur avec quatre passages principaux et avec l'aspiration dans le carter contrôlée par des lamelles.FIG. 7 shows the linear development of a cylinder according to the invention intended for an engine with four main passages and with the suction in the casing controlled by lamellae.

Dans ce cylindre, on voit comment les cavités longitudinales 20, pratiquées dans la chemise 21 du cylindre et en communication avec le carter, débouchent sur les fenêtres 22 de deux des passages principaux. Cette forme de réalisation se révèle particulièrement avantageuse pour des moteurs de petite cylindrée ayant une faible valeur d'alésage.In this cylinder, we see how the longitudinal cavities 20, formed in the jacket 21 of the cylinder and in communication with the casing, open onto the windows 22 from two of the main passages. This embodiment proves to be particularly advantageous for small displacement motors having a low bore value.

La figure 10 illustre une coupe transversale effectuée au droit des fenêtres des passages principaux du cylindre de la figure 7 en combinaison avec le piston selon l'invention. Dans cette figure on voit comment les cavités 21, pratiquées dans la chemise du cylindre et en communication avec le carter, s'alignent avec les cavités correspondantes 23 pratiquées dans l'enveloppe du piston 24 pour former des condu!ts 25FIG. 10 illustrates a cross section made at the right of the windows of the main passages of the cylinder of FIG. 7 in combination with the piston according to the invention. In this figure we see how the cavities 21, formed in the cylinder liner and in communication with the casing, align with the corresponding cavities 23 formed in the envelope of the piston 24 to form condu! Ts 25

Bien que le cylindre que l'on vient de décrire soit destiné à un moteur avec aspiration lamellaire dans le carter, le procédé selon l'invention peut être appliqué à des moteurs à deux temps avec aspiration lamellaire dans le cylindre, à soupape roulante ou avec n'importe quel autre dispositif de réglage de l'aspiration.Although the cylinder which has just been described is intended for an engine with lamellar aspiration in the casing, the method according to the invention can be applied to two-stroke engines with lamellar aspiration in the cylinder, with rolling valve or with any other suction control device.

Dans les exemples qui suivent, le procédé selon l'invention est appliqué à des moteurs à deux temps avec le conduit d'aspiration pratiqué dans le cylindre et contrôlé par des lamelles.In the examples which follow, the method according to the invention is applied to two-stroke engines with the suction duct formed in the cylinder and controlled by strips.

Sur la figure 8 le cylindre 26 présente quatre fenêtres 27 des passages principaux, un conduit d'échappement 28, et un conduit d'aspiration 29. Dans la chemise du cylindre on a aussi pratiqué trois cavités longitudinales, dont la cavité centrale 30 n'est pas reliée avec le carter et les cavités latérales 31 sont en communication avec le carter. Comme on peut le voir d'après la figure 11, qui est une coupe effectuée au droit des fenêtres des passages principaux du cylindre de la figure 8, en combinaison avec le piston selon l'invention, les cavités 31 sur la chemise du cylindre et les cavités 32 sur l'enveloppe du piston 33 forment des conduits 34 reliés au carter. Lesdits conduits 34, outre leur fonction de passages supplémentaires, ont aussi la fonction de conduits supplémentaires d'alimentation de gaz frais au carter. En effet, lorsque le piston effectue sa course descendante, développant la fonction de pompage des gaz frais du carter jusqu'à la chambre d'explosion, lesdits gaz frais passent à travers les passages principaux aussi bien qu'à travers les conduits 34 qui ont donc ladite fonction de passages supplémentaires mentionnnée plus haut. Lorsque, au contraire, le piston effectue sa course ascendante, développant la fonction d'aspiration des gaz frais dans le carter en fermant les fenêtres des passages principaux, les conduits 34 mettent en communication constante et directe le conduit d'aspiration prévu dans le cylindre et réglé par les lamelles avec le carter, en améliorant ainsi l'aspiration des gaz frais. Cet effet positif est obtenu sans accroître le volume mort du carter.In FIG. 8 the cylinder 26 has four windows 27 of the main passages, an exhaust duct 28, and a suction duct 29. In the jacket of the cylinder, three longitudinal cavities have also been made, including the central cavity 30 n ' is not connected to the housing and the lateral cavities 31 are in communication with the housing. As can be seen from FIG. 11, which is a section made in line with the windows of the main passages of the cylinder of FIG. 8, in combination with the piston according to the invention, the cavities 31 on the cylinder liner and the cavities 32 on the casing of the piston 33 form conduits 34 connected to the casing. Said conduits 34, in addition to their function of additional passages, also have the function of additional conduits for supplying fresh gas to the casing. Indeed, when the piston performs its downward stroke, developing the pumping function of the fresh gases from the casing to the explosion chamber, said fresh gases pass through the main passages as well as through the conduits 34 which have therefore said function of additional passages mentioned above. When, on the contrary, the piston performs its upward stroke, developing the function of suction of the fresh gases in the casing by closing the windows of the main passages, the conduits 34 put in constant and direct communication the suction conduit provided in the cylinder and adjusted by the slats with the casing, thereby improving the suction of fresh gases. This positive effect is obtained without increasing the dead volume of the casing.

La figure 9 montre un cylindre substantiellement semblable au cylindre illustré sur la figure 8, excepté le fait que les trois cavités longitudinales 35 pratiquées dans la chemise sont en communication avec le carter.Figure 9 shows a cylinder substantially similar to the cylinder illustrated in Figure 8, except that the three longitudinal cavities 35 formed in the jacket are in communication with the housing.

La figure 12 est une coupe effectuée sur la ligne centrale du conduit d'aspiration du cylindre de la figure 9 en combinaison avec le piston selon l'invention.Figure 12 is a section taken on the central line of the suction duct of the cylinder of Figure 9 in combination with the piston according to the invention.

La figure 13 montre un détail de la surface de séparation piston-cylindre d'un autre mode de réalisation possible selon l'invention. La référence 36 indique la chemise du cylindre et 37 est une cavité longitudinale pratiquée dans la chemise elle-même. Le bord supérieur de ladite cavité est substantiellement au droit des bords supérieurs des fenêtres des passages principaux, tandis que le bord inférieur est situé à proximité du point mort inférieur du piston. Ladite cavité 37 n'est pas en communication avec le carter. L'enveloppe du piston 38 montre une cavité longitudinale 39, tout à fait semblable aux cavités pratiquées dans le piston illustré dans les figures 4 et 5, qui s'aligne avec la cavité 37 pratiquée dans l'enveloppe.FIG. 13 shows a detail of the piston-cylinder separation surface of another possible embodiment according to the invention. The reference 36 indicates the cylinder liner and 37 is a longitudinal cavity formed in the liner itself. The upper edge of said cavity is substantially in line with the upper edges of the windows of the main passages, while the lower edge is located near the lower dead center of the piston. Said cavity 37 is not in communication with the casing. The envelope of the piston 38 shows a longitudinal cavity 39, quite similar to the cavities formed in the piston illustrated in FIGS. 4 and 5, which aligns with the cavity 37 formed in the envelope.

De cette façon, lorsque le piston effectue sa course descendante, une partie des gaz frais présents dans le carter pénètre dans la cavité 39 et depuis celle-ci dans la cavité 37 ; lorsque le bord supérieur du piston descend au dessous de l'extrémité supérieure de la cavité 37, les gaz frais présents dans la cavité elle-même pénètrent dans la chambre d'explosion s'ajoutant aux gaz frais qui s'écoulent des passages principaux. On obtient ainsi une amélioration des conditions de balayage du cylindre sans accroître le volume mort du carter et sans besoin de modifier le carter lui-même. Il va sans dire que plusieurs cavités alignées entre elles peuvent être pratiquées sur la chemise du cylindre et sur l'enveloppe du piston.In this way, when the piston performs its downward stroke, part of the fresh gases present in the casing enters the cavity 39 and from the latter into the cavity 37; when the upper edge of the piston descends below the upper end of the cavity 37, the fresh gases present in the cavity itself penetrate into the explosion chamber adding to the fresh gases which flow from the main passages. This improves the scanning conditions of the cylinder without increasing the dead volume of the housing and without the need to modify the housing itself. It goes without saying that several cavities aligned with each other can be made on the cylinder liner and on the piston casing.

Claims (8)

1. Procédé pour améliorer les conditions de balayage et éventuellement l'aspiration des gaz frais dans le carter d'un moteur à combustion interne à deux temps, caractérisé en ce qu'en correspondance de la surface de séparation piston-cylindre, on forme une ou plusieurs cavités (19,34) propres à mettre en communication directe l'intérieur du carter avec la chambre d'explosion lorsque le piston se trouve à proximité de son point mort inférieur.1. Method for improving the sweeping conditions and possibly the suction of fresh gases in the casing of a two-stroke internal combustion engine, characterized in that, in correspondence with the piston-cylinder separation surface, a or several cavities (19,34) suitable for placing the interior of the casing in direct communication with the explosion chamber when the piston is near its bottom dead center. 2. Groupe piston-cylindre pour un moteur à combustion interne à deux temps, caractérisé en ce que la surface de séparation piston-cylindre présente une ou plusieurs cavités (19,34) qui relient directement l'intérieur du carter avec la chambre d'explosion pour des positions du piston situées à proximité de son point mort intérieur.2. Piston-cylinder group for a two-stroke internal combustion engine, characterized in that the piston-cylinder separation surface has one or more cavities (19,34) which directly connect the interior of the housing with the explosion for piston positions located near its internal dead center. 3. Groupe piston-cylindre selon la revendication 2, caractérisé en ce que ladite ou lesdites cavités sont disposées longitudinalement en face de la lumière d'échappement.3. Piston-cylinder group according to claim 2, characterized in that said one or more cavities are arranged longitudinally opposite the exhaust port. 4. Groupe piston-cylindre selon la revendication 2 ou 3, caractérisé en ce que ladite ou lesdites cavités (19,34) sont disposées latéralement aux fenêtres des passages principaux.4. Piston-cylinder group according to claim 2 or 3, characterized in that said one or said cavities (19,34) are arranged laterally to the windows of the main passages. 5. Groupe piston-cylindre selon la revendication 3 ou 4, caractérisé en ce que l'extrémité supérieure de ladite ou desdites cavités est sensiblement au droit du bord supérieur des fenêtres (8,22) des passages principaux, ladite proximité du point mort inférieur dons le mouvement du piston étant définie par la coïncidence des segments élastiques avec lesdites extrémités supérieures des cavités.5. Piston-cylinder group according to claim 3 or 4, characterized in that the upper end of said one or more cavities is substantially in line with the upper edge of the windows (8,22) of the main passages, said proximity to the bottom dead center don the movement of the piston being defined by the coincidence of the elastic segments with said upper ends of the cavities. 6. Groupe piston-cylindre selon l'une des revendications 2 à 5, caractérisé en ce que ladite ou lesdites cavités sont pratiquées au moins en partie dans la paroi intérieure du cylindre (1,26) et s'étendent -jusqu'à l'intérieur du carter.6. Piston-cylinder group according to one of the resale cations 2 to 5, characterized in that the said cavity or cavities are formed at least partially in the internal wall of the cylinder (1,26) and extend -up to the interior of the casing. 7. Groupe piston-cylindre selon la revendication 6, caractérisé en ce qu'en correspondance d'une ou plusieurs des cavités (9,20) pratiquées dans la chemise (3,21) du cylindre l'enveloppe du piston (11,24) présente des cavités (17,23) s'étendant depuis son bord inférieur jusqu'au dessous des sièges de logement dudit ou desdits segments élastiques.7. Piston-cylinder group according to claim 6, characterized in that in correspondence with one or more of the cavities (9,20) formed in the jacket (3,21) of the cylinder the envelope of the piston (11,24 ) has cavities (17,23) extending from its lower edge to the underside of the housing seats of said elastic segment (s). 8. Groupe piston-cylindre selon l'une des revendications 2 à 5, caractérisé en ce que ladite ou lesdites cavités sont pratiquées au moins en partie dans la chemise (3,21) du cylindre (1,26) et s'étendent jusqu'à un point situé au dessus du carter et en ce que l'enveloppe (12) du piston présente, en correspondance d'une ou plusieurs des cavités pratiquées dans le cylindre, des cavités s'étendant depuis son bord inférieur jusqu'au dessous des sièges de logement du ou des segments élastiques.8. Piston-cylinder group according to one of claims 2 to 5, characterized in that said one or more cavities are formed at least partly in the jacket (3,21) of the cylinder (1,26) and extend up to '' at a point located above the casing and in that the casing (12) of the piston has, in correspondence with one or more of the cavities formed in the cylinder, cavities extending from its lower edge to the bottom housing seats of the elastic segment or segments.
EP86113495A 1985-10-02 1986-10-01 Piston-cylinder unit for a two-stroke internal combustion engine Expired - Lifetime EP0217374B1 (en)

Priority Applications (1)

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AT86113495T ATE50318T1 (en) 1985-10-02 1986-10-01 PISTON-CYLINDER UNIT OF A TWO-STROKE ENGINE.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
IT22334/85A IT1185972B (en) 1985-10-02 1985-10-02 METHOD TO INCREASE THE PERFORMANCE OF TWO STROKE INTERNAL COMBUSTION ENGINES
IT2233485 1985-10-02

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EP0217374A1 true EP0217374A1 (en) 1987-04-08
EP0217374B1 EP0217374B1 (en) 1990-02-07

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EP86113495A Expired - Lifetime EP0217374B1 (en) 1985-10-02 1986-10-01 Piston-cylinder unit for a two-stroke internal combustion engine

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EP (1) EP0217374B1 (en)
AT (1) ATE50318T1 (en)
DE (1) DE3668943D1 (en)
ES (1) ES2013701B3 (en)
FR (1) FR2588043B1 (en)
IN (1) IN164255B (en)
IT (1) IT1185972B (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0391793A1 (en) * 1989-04-04 1990-10-10 SOCIETE NOUVELLE RACING KART DEVELOPPEMENT, "SOCIETE NOUVELLE R.K.D.", Société anonyme dite: Two-stroke internal-combustion engine
US20140326130A1 (en) * 2011-10-28 2014-11-06 Ks Kolbenschmidt Gmbh Functionally optimized design of a cylinder liner

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2248411A1 (en) * 1973-10-18 1975-05-16 Halder Engines Ltd Two-stroke engine with inlet via crank case - has exhaust ports and overflow ducts from crank case to cylinder in cylinder wall
US4287860A (en) * 1979-03-28 1981-09-08 Kawasaki Jukogyo Kabushiki Kaisha Two-cycle engine
US4294202A (en) * 1978-09-12 1981-10-13 Performance Industries, Inc. Fuel porting for two cycle internal combustion engine

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2248411A1 (en) * 1973-10-18 1975-05-16 Halder Engines Ltd Two-stroke engine with inlet via crank case - has exhaust ports and overflow ducts from crank case to cylinder in cylinder wall
US4294202A (en) * 1978-09-12 1981-10-13 Performance Industries, Inc. Fuel porting for two cycle internal combustion engine
US4287860A (en) * 1979-03-28 1981-09-08 Kawasaki Jukogyo Kabushiki Kaisha Two-cycle engine

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0391793A1 (en) * 1989-04-04 1990-10-10 SOCIETE NOUVELLE RACING KART DEVELOPPEMENT, "SOCIETE NOUVELLE R.K.D.", Société anonyme dite: Two-stroke internal-combustion engine
US20140326130A1 (en) * 2011-10-28 2014-11-06 Ks Kolbenschmidt Gmbh Functionally optimized design of a cylinder liner
US10359000B2 (en) 2011-10-28 2019-07-23 Ks Kolbenschmidt Gmbh Functionally optimized design of a cylinder liner

Also Published As

Publication number Publication date
FR2588043A1 (en) 1987-04-03
FR2588043B1 (en) 1989-07-28
IT8522334A0 (en) 1985-10-02
ES2013701B3 (en) 1990-06-01
IT1185972B (en) 1987-11-18
ATE50318T1 (en) 1990-02-15
EP0217374B1 (en) 1990-02-07
DE3668943D1 (en) 1990-03-15
IN164255B (en) 1989-02-11

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