DE102019008405A1 - Connection flange for connecting an air filter to an internal combustion engine, cylinders for an internal combustion engine and an internal combustion engine - Google Patents

Abstract

A connecting flange (45) for connecting an air filter (41) to an internal combustion engine (1) has an air duct (10) and a mixture duct (21) which are guided separately from one another. The connection flange (45) has an end face (47) at which the section of the air duct (10) guided in the connection flange (45) and the section of the mixture duct (21) guided in the connection flange open. The connecting flange (45) has a first drainage channel (51) for the mixture channel (21) which forms a connection between the mixture channel (21) and a first connection area (78, 78 '). The connecting flange (45) has a second drainage channel (52) for the air channel (10), which forms a connection between the air channel (10) and a second connection area (79, 79 ') that is separate from the first drainage channel (51). A cylinder (2) for an internal combustion engine (1) preferably has a first drainage channel (51) for the mixture channel (21) and a second drainage channel (52) for the air channel (10), which in the cylinder (2) is separated from the first drainage channel ( 51) is performed separately. For an internal combustion engine (1) it is provided that the first drainage channel (51) connects the mixture channel (21) with the crankcase interior (29) in at least one position of the piston (5) and that the second drainage channel (52) is in at least one position of the The piston (5) connects the air duct (10) with the crankcase interior (29).

Description

The invention relates to a connecting flange for connecting an air filter to an internal combustion engine of the type specified in the preamble of claim 1, a cylinder for an internal combustion engine of the type specified in the preamble of claim 14 and an internal combustion engine of the type specified in the preamble of claim 16.

From the US 2013/0098325 A1 an internal combustion engine with a connecting flange for connection to an air filter is known, in which an air duct and a mixture duct are guided separately from one another. In order to discharge the mixture from the air filter chamber, a connecting channel is provided between the air filter chamber and the crankcase or between the air filter chamber and the intake channel.

From the DE 101 43 435 A1 an internal combustion engine with an intake manifold is known, the cylinder of which has a drainage channel through which the mixture, which is collected in the end face of the connection port of the cylinder from the mixture channel, is discharged into the crankcase interior.

The invention is based on the object of creating a connecting flange for connecting an air filter to an internal combustion engine, with which a favorable running behavior of the internal combustion engine can be achieved. A further object of the invention is to specify a cylinder for an internal combustion engine which enables favorable running behavior, and to specify an internal combustion engine with favorable running behavior.

With regard to the connecting flange, this object is achieved by a connecting flange having the features of claim 1. With regard to the cylinder, the object is achieved by a cylinder with the features of claim 14. With regard to the internal combustion engine, the object is achieved by an internal combustion engine having the features of claim 16.

The connecting flange has a first drainage channel for the mixture channel, which forms a connection between the mixture channel and a first connection area. The connecting flange also has a second drainage channel for the air channel. The second drainage channel forms a connection formed separately from the first drainage channel between the air channel and a second connection area.

Fuel that has collected in the mixture channel, for example fuel that has deposited on the walls of the mixture channel, can be discharged via the first drainage channel. Fuel that has collected in the air channel can be discharged via the second drainage channel. The fuel can have entered the air duct, for example, through leaks between the air duct or the mixture duct. Fuel can also have passed from the mixture duct into the air duct via a clean room of the air filter.

A connection component for connecting the respective drainage channel to the crankcase interior, such as, for example, a connecting hose or a component in which a channel for the drainage channel or channels is formed, can be arranged on the connection areas. The component in which a channel for the first and / or the second drainage channel is formed is in particular a cylinder or a crankcase component of an internal combustion engine. The connection areas are preferably used to connect to components that establish a connection between the drainage channels and the interior of the crankcase.

Because the two connection areas are formed separately from one another, the first drainage channel and the second drainage channel can be connected to the crankcase interior separately from one another. No connection is created between the air duct and the mixture duct via the drainage ducts. This also avoids influencing the pressure conditions in the air duct and mixture duct via the drainage ducts. This enables an internal combustion engine to run well.

Because the drainage channels are designed separately from one another, a high idling stability of the internal combustion engine, in particular when pivoting the internal combustion engine, can be achieved. This is particularly advantageous when used in a hand-held tool, in particular when used in a chainsaw. When the engine is idling, the fuel that has collected in the air duct is not sucked in via the crankcase, but reaches the combustion chamber directly via the piston pocket and the overflow window. As a result, this mixture may not be completely well mixed and atomized. This can lead to the internal combustion engine stalling while idling. This is prevented by the second drainage channel. The accumulation of fuel in the mixture channel is particularly advantageous in the case of a rich come down, i.e. when the throttle valve is suddenly closed, for example after actuating full throttle.

At least one drainage channel is advantageously connected to the mixture channel or to the air channel via at least one drainage opening. Preferably, the first drainage channel is over a first Drainage opening connected to the mixture channel. The second drainage channel is connected to the air channel in particular via at least one second drainage opening. The at least one drainage opening is formed in the connecting flange so that accumulated fuel can be discharged from the portion of the mixture channel and / or air channel formed in the connecting flange. Accordingly, the mixture can be sucked out of the mixture channel and / or from the air channel by means of negative pressure from the crankcase.

The end face of the connecting flange is preferably used to connect to a cylinder connecting flange of a cylinder of an internal combustion engine.

At least one drainage opening is preferably formed on the end face of the connecting flange. This results in a simple structure. The drainage opening can be designed as a recess on the end face of the connecting flange. This in particular simplifies the manufacture of the connecting flange by injection molding, in particular as a plastic injection molded part. At least one connection area is preferably arranged on the end face. In a particularly preferred embodiment, both connection areas are arranged on the end face. As a result, the connection areas can be connected in a simple manner to a connection opening on the cylinder connection flange. At least one drainage channel from the drainage opening to the connection area is preferably designed as a recess on the end face of the connection flange.

The first connection area is advantageously arranged on the end face separately from the mixture channel. The second connection area is preferably arranged separately from the air duct on the end face. In a particularly preferred embodiment, the second drainage channel is designed as an annular channel. A symmetrical flow guidance and arrangement can thereby be achieved. Due to the design as an annular channel, fuel can be safely discharged from the air channel via the drainage channel even if the position of the connecting flange changes in the space. A changing position of the connecting flange in space can result, for example, if the working position or working position of a hand-held implement provided with the connecting flange changes. This is particularly advantageous when using the connecting flange in a hand-held tool such as a power saw, a brush cutter, a blower, a hedge trimmer, a sprayer, a power cutter or the like. The drainage channel can be designed as an annular channel with a small space requirement with a sufficiently large flow cross-section.

The first connection area and the second connection area are preferably arranged on the side of the mixture channel facing away from the air channel. The connection areas are accordingly further away from the air duct on the front side than the mixture duct. As a result, the connection areas for connection to the crankcase interior can be connected in a simple manner to the channel sections formed in the cylinder. The result is a simple flow guidance of the drainage channels in the cylinder. The second connection area is preferably arranged on the side of the first connection area facing away from the mixture channel. The second connection area is accordingly arranged on the end face further away from the mixture duct than the first connection area. The drainage channels preferably open into the cylinder bore of the internal combustion engine in an area that is controlled by the piston. The fact that the second connection area is arranged on the side of the first connection area facing away from the mixture channel results in a simple channel routing in the cylinder in particular when the second connection area is opened towards the crankcase interior during the upward stroke of the piston in front of the first connection area. As a result, on the upward stroke of the piston, fuel is first sucked out of the air duct, and only after further movement of the piston towards its top dead center is the first drainage duct to the crankcase interior opened and fuel sucked out of the mixture duct.

In an advantageous alternative configuration, at least one connection area is arranged on a circumferential side of the connection flange. This can be particularly advantageous if the connection area is to be connected to the crankcase interior via a separate hose line.

The second drainage channel preferably opens into the air channel with at least two drainage openings. This is particularly advantageous when the second drainage channel is designed as an annular channel. Two drainage openings are particularly advantageous when the air duct has a comparatively large extent in one direction. At least two drainage openings can ensure good removal of accumulated fuel over the entire cross section of the drainage channel. This is particularly advantageous for a connecting flange that is pivoted during operation, such as when used in a hand-held tool such as a chainsaw or the like.

The end face of the connecting flange is preferably provided for connection to a cylinder connecting flange of a cylinder of an internal combustion engine.

For a cylinder for an internal combustion engine, in which a cylinder bore is formed, with at least one overflow channel, with a mixture channel for the supply of a fuel / air mixture and with an air channel which can be connected to at least one overflow channel for the supply of scavenging air is provided: that the cylinder has a first drainage channel for the mixture channel, and that the cylinder has a second drainage channel for the air channel, the second drainage channel being guided in the cylinder separately from the first drainage channel.

The cylinder advantageously has a cylinder connection flange on which a first connection opening for the first drainage channel and a second connection opening for the second drainage channel are formed. The first connection opening is to be arranged in particular on the end face of the connection flange in the area of the first connection area and the second connection opening on the end face of the connection flange on the second connection area.

For an internal combustion engine with a cylinder, it is provided that the internal combustion engine has a first drainage channel, which connects the mixture channel with the crankcase interior in at least one position of the piston, the first drainage channel opening into the crankcase interior with a first opening, and that a second drainage channel is provided which connects the air duct with the crankcase interior in at least one position of the piston. Because two drainage channels are provided for the air channel and the mixture channel, a connection between the air channel and the mixture channel via the drainage channels is avoided. The first drainage channel and the second drainage channel are preferably routed separately from one another up to the point where they open into the crankcase interior. The first drainage channel and the second drainage channel preferably open into the crankcase interior with different mouth openings.

At least one mouth opening of a drainage channel is advantageously controlled by the piston. As a result, the control time at which the drainage channel is connected to or separated from the crankcase interior can be predetermined structurally. In a preferred embodiment, both orifices are controlled by the piston. The orifices are preferably arranged on the cylinder bore in such a way that they open into the crankcase interior at different control times during the upward stroke of the piston. The second orifice opening is preferably connected to the crankcase interior during the upward stroke of the piston in front of the first orifice opening of the first drainage channel. This arrangement of the orifices on the cylinder bore ensures that a negative pressure is first generated at the second orifice opening via the second drainage channel and only then a negative pressure is generated in the mixture channel via the first drainage channel. This makes it possible to ensure that the negative pressure generated in the air duct is sufficiently large to reliably suck fuel that has accumulated in the air duct into the second drainage duct.

The connection of the air duct to the at least one overflow duct is advantageously established by the piston, and the second orifice opening of the second drainage duct is arranged on the cylinder bore in such a way that the second orifice opening on the upward stroke of the piston already covers a crankshaft angle of at least 30 °, in particular at least 40 ° is open to the crankcase interior when the at least one overflow duct is connected to the air duct. This ensures that a negative pressure is already present at the mouth opening via the second drainage channel before a negative pressure is generated in the air channel via the overflow channel. The mixture channel advantageously opens into the crankcase interior with a mixture inlet opening controlled by the piston. The first orifice opening of the first drainage channel and the mixture inlet opening are advantageously arranged on the cylinder bore in such a way that the first orifice opening is opened during the upward stroke of the piston over a crankshaft angle of less than 30 °, in particular less than 20 °, before the mixture inlet opening to the crankcase interior is opened. At least one drainage opening is advantageously arranged at a parting plane between two components delimiting the mixture duct and the air duct.

The internal combustion engine advantageously has a fuel pump which is driven by the fluctuating pressure in the crankcase interior via a pulse channel. The pulse channel advantageously ends at a pulse channel opening into the crankcase interior, which is open regardless of the position of the piston in relation to the crankcase interior. The impulse channel opening is accordingly open in every position of the piston towards the crankcase interior. This enables continuous operation of the fuel pump.

• 1 eine schematische Darstellung eines Verbrennungsmotors,
• 2 eine schematische Darstellung eines handgeführten Arbeitsgeräts mit dem Verbrennungsmotor aus 1,
• 3 eine schematische, perspektivische Darstellung eines Vergasers und eines Verbindungsflanschs des Verbrennungsmotors aus 1,
• 4 eine schematische, perspektivische Darstellung des Zylinderanschlussflanschs des Zylinders des Verbrennungsmotors aus 1,
• 5 eine schematische Seitenansicht von Vergaser und Verbindungsflansch aus 3 an dem Zylinder aus 4, wobei der Verbindungsflansch als durchsichtiges Bauteil und die im Verbindungsflansch ausgebildeten Kanäle mit durchgezogener bzw. gestrichelter Linie dargestellt sind,
• 6 eine ausschnittsweise perspektivische Schnittdarstellung von Vergaser, Verbindungsflansch und Zylinder aus 5,
• 7 eine schematische, ausschnittsweise perspektivische Darstellung von Verbindungsflansch und Zylinder aus 6, wobei der Verbindungsflansch als durchsichtiges Teil und die im Verbindungsflansch geführten Kanäle mit durchgezogener Linie dargestellt sind,
• 8 eine ausschnittsweise perspektivische Darstellung des Zylinderanschlussflanschs mit daran angeordnetem Verbindungsflansch in einer Darstellung entsprechend 7,
• 9 eine Abwicklung von Zylinderbohrung und Kolben nahe des unteren Totpunkts des Kolbens.

Embodiments of the invention are explained below with reference to the drawing. Show it:

• 1 a schematic representation of an internal combustion engine,
• 2 a schematic representation of a hand-held tool with the internal combustion engine 1 ,
• 3rd a schematic, perspective illustration of a carburetor and a connecting flange of the internal combustion engine 1 ,
• 4th a schematic, perspective illustration of the cylinder connecting flange of the cylinder of the internal combustion engine 1 ,
• 5 a schematic side view of the carburetor and connecting flange 3rd on the cylinder 4th The connecting flange is shown as a transparent component and the channels formed in the connecting flange are shown with a solid or dashed line,
• 6th a partial perspective sectional view of the carburetor, connecting flange and cylinder 5 ,
• 7th a schematic, partial perspective view of the connecting flange and cylinder 6th , whereby the connecting flange is shown as a transparent part and the channels guided in the connecting flange are shown with a solid line,
• 8th a fragmentary perspective illustration of the cylinder connection flange with the connecting flange arranged thereon in a corresponding illustration 7th ,
• 9 a development of the cylinder bore and piston near bottom dead center of the piston.

1 shows schematically the structure of an internal combustion engine 1 . The internal combustion engine 1 is designed as a two-stroke engine that works with a flushing system. The internal combustion engine 1 has a cylinder 2 on, in which a combustion chamber 3rd is trained. The combustion chamber 3rd is from one in the cylinder 2 reciprocating piston 5 limited. The piston 5 drives via a connecting rod 6th one in a crankcase 4th around an axis of rotation 8th rotatably mounted crankshaft 7th at. The crankshaft 7th is used in particular to drive a tool of an implement or the like. The crankcase 4th has a crankcase interior 29 on where the crankshaft 8th rotates during operation. In the cylinder 2 is a cylinder bore 26th formed in which the piston 5 is led. At the cylinder bore 26th opens an air duct 10 with an air inlet port 9 . From the combustion chamber 3rd also leads one in the cylinder bore 26th arranged outlet opening 11 .

The cylinder 2 has at least one overflow channel 12th , 15th on that of the crankcase interior 29 in structurally predetermined positions fluidically with the combustion chamber 3rd connects. In the exemplary embodiment, there are two transfer channels close to the inlet 12th and two transfer channels close to the outlet 15th intended. Overflow ducts 12th and 15th are to the in 1 Section plane shown arranged symmetrically. The transfer ducts close to the inlet 12th open with overflow windows close to the inlet 13th into the combustion chamber 3rd and the transfer channels near the outlet 15th with overflow windows close to the outlet 16 . The air inlet opening 9 is preferably in the area of the bottom dead center of the piston 5 via at least one piston pocket 14th with at least one, preferably all, overflow windows 13th , 16 connected to in the overflow ducts 12th and 15th Upstream flushing air.

The internal combustion engine 1 has a mixture channel 21 on, the one with a mixture inlet port 20th on the cylinder bore 26th flows out. The air inlet opening 9 , the mixture inlet opening 20th who have favourited the air transfer window 13th and 16 as well as the outlet opening 11 are from a piston skirt 66 of the piston 5 controlled, so are dependent on the position of the piston 5 closed or with the combustion chamber 3rd or the crankcase interior 29 connected.

The internal combustion engine 1 draws in ambient air through an air filter 41 on, the filter material 42 having. A carburetor is preferably used to supply fuel 17th intended. In the carburetor 17th is a section of an intake duct 18th guided. The intake duct 18th connects the clean room of the air filter 41 with the air inlet opening 9 and the mixture inlet port 20th . In the carburetor 17th is in the exemplary embodiment a partition 19th provided that the intake duct 18th in the air duct 10 and the mixture channel 21 Splits. It can be provided that the partition 19th only downstream of the carburetor 17th begins. It can also be provided that the partition 19th all the way to the clean room of the air filter 41 extends, as in 1 shown schematically.

The carburetor 17th has a carburetor housing 22nd on. In the carburetor 17th is in the intake duct 18th a venturi 23 educated. In the carburetor housing 22nd is a throttle element, in the exemplary embodiment a throttle valve 24 , pivoted. For storing the throttle valve 24 is in the exemplary embodiment a throttle shaft 25th intended. It can be provided that at least one choke element, for example a choke flap, in the intake duct upstream of the throttle element 18th is stored. In the carburetor 17th advantageously open into a main fuel opening 28 as well as several secondary fuel openings in the exemplary embodiment 27 into the mixture duct 21 . For delivering fuel to the fuel openings 27 , 28 is a fuel pump 43 intended. In the exemplary embodiment is the fuel pump 43 in the carburetor housing 22nd arranged. The fuel pump 34 is via a pulse channel 57 with the crankcase interior 29 connected. The impulse channel 57 opens at an impulse channel mouth 70 into the crankcase interior 29 . The Impulse channel muzzle 70 is arranged in an area that is independent of the position of the piston 5 always to the crankcase interior 29 is open. How 2 shows, the impulse channel opens 57 in one area in the crankcase interior 29 that is not within the from the piston 5 swept area of the cylinder bore 26th lies. The pulse channel preferably opens 57 in the crankcase 4th into the crankcase interior 29 . The pressure fluctuations in the crankcase interior 29 are via the pulse channel 57 transmit and thus drive the fuel pump 43 at.

In 2 is an exemplary embodiment of an implement that has an internal combustion engine 1 having a chainsaw 30th shown. The chainsaw 30th has a housing 31 on, which can be designed as a closed housing or composed of several housing parts. The chainsaw 30th has a rear handle 32 as well as a bow handle 35 for driving the chainsaw 30th in operation. On the rear handle 32 is a throttle 33 to operate the combustion engine 1 stored. The rear handle 32 also has a throttle lock 34 on, which is to be operated before the throttle 33 can be operated. The tool of the chainsaw 30th is a saw chain 38 that from the internal combustion engine 1 on a guide rail 37 is driven in rotation. Between the bow handle 35 and guide rail 37 a hand guard extends 36 , which can be provided for triggering a chain brake, not shown. The hand-held tool, in the exemplary embodiment the chainsaw, is advantageous 30th , started by an operator by means of a manual starting device, for example a pull-rope starter. In 2 is a starter grip 39 the starting device shown.

The carburetor 17th is with the cylinder 2 of the internal combustion engine 1 about an in 1 connection flange shown schematically 45 connected. The connecting flange 45 is in 3rd shown in detail. 3rd shows a perspective view of an end face 47 of the connection flange 45 . The front side 47 is the downstream, second end face of the connecting flange 45 . The second face 47 is for arrangement on an in 4th cylinder connection flange shown schematically 60 intended. As a cylinder connection flange 60 is understood here as the connection surface on which the connecting flange 45 or a possible intermediate component. The mixture channel 21 opens with a mixture channel opening 49 on the second face 47 , how 3rd shows. On the second face 47 is a first drainage channel 51 guided. The first drainage channel 51 is in the exemplary embodiment as a recess on the second end face 47 educated. The first drainage channel 51 connects the mixture duct 21 at the mixture duct opening 49 with a first connection area 78 . The first connection area 78 of the connection flange 45 serves to connect a further section of the first drainage channel 51 in at least one position of the piston 5 a connection to the crankcase interior 29 manufactures. The first connection area 78 is as a deepening 58 in the second face 47 educated. The depression 58 forms both part of the first drainage channel 51 as well as the first connection area 78 . Also another design of drainage channel 51 and connection area 78 however, it can be beneficial. The mixture duct opening 49 , the first drainage channel 51 and the first connection area 78 are preferably of a common seal 53 surrounded, in the exemplary embodiment as a survey on the second end face 47 is trained.

The air duct 10 opens with an air duct opening 48 on the second face 47 . At the air duct opening 48 is a flow guide element 50 provided that in a corresponding connection opening 67 on the cylinder connection flange 60 protrudes. The connection opening 67 is in 6th recognizable. Through the flow guide element 50 a streamlined ducting is achieved and at the same time enables the cylinder 2 and connecting flange 45 can be easily manufactured from metal or plastic in a casting process with a reusable mold.

The air duct opening 48 is via a second drainage channel 52 with a second connection area 79 connected. The second drainage channel 52 is in the embodiment as a recess 59 in the cylinder connection flange 60 educated. The second drainage channel 52 is preferably designed as an annular channel, which partially extends around the mouth opening 49 and the first connection area 78 extends. The second drainage channel 52 and the air duct opening 48 are preferably from a seal 54 surround.

On the second face 47 preferably opens the pulse channel 57 that from the first connection area 78 through a section of the seal 53 is separated. On the second face 47 preferably open into four fastening openings 55 . Will be the connecting flange 45 on the cylinder connection flange 60 ( 4th ) arranged, so come the mounting holes 55 at fastening openings 64 ( 8th ) of the cylinder 2 to lie in, for example, screws through the mounting holes 55 can be screwed through. This allows the connecting flange 45 in a simple way on the cylinder 2 be fixed.

Through the cylinder connection flange 60 are the impulse channel 57 and the drainage channels 51 and 52 guided. For the first drainage channel 51 is a connection opening 61 in the cylinder connection flange 60 provided that overlap the first connection area 78 comes to rest. For the second drainage channel 52 is a connection opening 62 provided that overlap the second connection area 79 comes to rest. The impulse channel 57 points in the cylinder connection flange 60 a connection opening 63 on. How 4th also shows the air duct divides 9 in the cylinder in two branches 9a and 9b on that with air intakes 9a and 9b on the cylinder bore 29 open out (see 11 ).

5 shows the arrangement of the connecting flange 45 between carburetor 17th and cylinder 2 schematic. The connecting flange 45 is with a first end face 46 on the carburetor 17th arranged. The second face 47 of the connecting flange 45 related to the direction of flow from the carburetor 17th to the cylinder 2 the downstream face of the connecting flange 45 is adjacent to the cylinder 2 . In the exemplary embodiment is between the second end face 47 and the connecting flange 45 a shield plate 44 ( 7th ) arranged. It can also be provided that the connecting flange 45 directly on the cylinder connection flange 60 of the cylinder 2 is arranged. Other or further components between the connecting flange 45 and cylinder connection flange 60 can be beneficial. The second face 47 lies in relation to the direction of flow in the intake duct 18th closer to the cylinder connection flange 60 as the first face 46 .

How 5 shows, run the air duct 10 , the mixture channel 21 and the impulse channel 57 from the first face 46 to the second face 47 of the connecting flange 45 . The air duct is advantageous 10 , the mixture channel 21 and the impulse channel 57 on the front sides 46 and 47 from the connecting flange 45 out. In 5 is the second drainage channel 52 recognizable, the one on the second face 47 runs. 5 also shows a drainage opening 74 with which the drainage channel 52 in the air duct 10 flows out.

6th shows the arrangement of the carburetor 17th , Connecting flange 45 and cylinder 2 .

How 6th shows, the first drainage channel opens 51 via a first drainage opening 73 into the mixture duct 21 . The first drainage opening 73 is on the second face 47 of the connecting flange 45 arranged. The first drainage opening 73 is at the connection area 78 adjacent and the air duct 10 remote side of the mixture channel 21 arranged. The first drainage channel 51 opens with a first mouth opening 71 on the cylinder bore 26th . The second drainage channel 52 opens with a second mouth opening 72 on the cylinder bore 26th . The mouth openings 71 and 72 the drainage channels 51 and 52 lie in the same the longitudinal axis of the cylinder 81 ( 1 ) containing section plane through the cylinder 2 . The mixture inlet opening is also located in the exemplary embodiment 20th in this cutting plane. The mouth opening 72 of the second drainage channel 52 lies parallel to the longitudinal axis of the cylinder 81 measured further away from the combustion chamber 3rd ( 1 ) removed than the first orifice 71 . The first mouth opening 71 is advantageously between the mixture inlet opening 20th and the second orifice 72 . The second mouth opening 72 points in the direction of the cylinder longitudinal axis 81 measured a greater distance to the overflow windows 13th and 16 ( 1 ) as the first mouth opening 71 .

How 6th shows are the first connection area 78 and the second connection area 79 on the second face 47 of the connecting flange 45 arranged. The connecting flange 45 has a peripheral side 76 on that extends from the first face 46 to the second face 47 extends.

In an alternative design of the connecting flange 45 open into a first connection area 78 ' and a second connection area 79 ' the drainage channels 51 ' and 52 ' on the circumference side 76 and can be connected there with the following components, for example with a connection hose. The drainage channels 51 ' and 52 ' can at least partially as channels closed on the circumference, for example as bores, and / or as depressions in the second end face 47 be trained. The alternative design is in 6th shown with dashed line.

In the 7th and 8th is the arrangement of the connecting flange 45 on the shielding plate 44 of the cylinder 2 shown. As the 7th and 8th show, the second drainage channel opens 52 , which is preferably designed as an annular channel, with two drainage openings 74 and 75 in the air duct 10 . The further, third drainage opening 75 is in 8th shown. As the 7th shows, the drainage channel runs 52 as an elongated recess over the central area of the circular connection area 79 .

8th also shows the connection opening 63 of the pulse channel 57 with which the pulse channel 57 at the front 47 opens out to one in the cylinder 2 formed section of the pulse channel 57 connects.

9 shows a development of the piston 5 and the cylinder bore 29 . 9 shows the piston 5 near its bottom dead center. The air inlet openings are in this piston position 9a and 9b from the piston skirt 66 of the piston 5 locked. The overflow window 13th and 16 as well as the outlet 11 are to the combustion chamber 3rd open. In this piston position, the flow flows in the overflow channels 12th and 15th upstream fresh mixture through the overflow window 13th and 16 into the combustion chamber 3rd . The Mouth openings 71 and 72 the drainage channels 51 and 52 ( 4th ) are from the piston skirt 66 locked. Also the mixture inlet opening 20th is from the piston skirt 66 locked.

With a further upward stroke of the piston 5 close the overflow window 13th and 16 to the combustion chamber 3rd down. Also the outlet 11 closes. By the movement of the piston 5 becomes mixture in the combustion chamber 3rd compressed. The second mouth opening 72 of the second drainage channel 52 begins with a further upward stroke of the piston 5 to the crankcase interior 29 to open. This creates mixture that is in the air duct 10 has precipitated, due to the inside of the crankcase 29 prevailing negative pressure through the drainage channel 51 into the crankcase interior 29 discharged.

After another upstroke of the piston 5 opens the mouth 72 completely to the crankcase interior 29 down. With a further upward stroke, the mouth opening also opens 71 to the crankcase interior 29 down. About the mouth opening 71 and the first drainage channel 51 is also mixture that is in the mixture channel 21 has accumulated in the crankcase interior 29 sucked off. The mixture inlet opening 20th begins after another upward stroke to the crankcase interior 29 to open. Due to the inside of the crankcase 29 prevailing negative pressure during the upward movement of the piston 5 the mixture is created through the mixture inlet 20th into the crankcase interior 29 sucked in. In that the mouth opening 71 in front of the mixture inlet 20th into the crankcase interior 29 opens, it is ensured that in the drainage channel 51 a sufficiently large negative pressure to suck the mixture out of the mixture channel 21 prevails.

The overflow window 13th and 16 on the upstroke of the piston 5 first with the piston pockets 14a and 14b connected. To the air intake openings 9a and 9b are the piston pockets 14a and 14b initially still closed so that no fresh mixture has yet come through the overflow window 13th and 16 in the overflow ducts 12th and 15th can flow in. The outlet opening 11 is largely closed. On further upstroke, the exhaust port becomes 11 completely closed, and the mixture in the combustion chamber 3rd is further compressed and in the area of the top dead center of the piston 5 from an in 1 illustrated spark plug 82 ignited.

The mixture inlet 20th is with the crankcase interior 29 connected while the piston 5 further towards the combustion chamber 3rd emotional. The air intake openings 9a and 9b are with the piston pockets 14a and 14b connected so that in the overflow ducts 12th and 15th through the overflow window 13th and 16 Air from the air duct 10 can be sucked. The suction of air into the overflow ducts 12th and 15th occurs only after both orifices 71 and 72 the drainage channels 51 and 52 with the crankcase interior for a long time 29 are connected.

At the top dead center of the piston 5 are the overflow windows 13th and 16 all the way to the piston pockets 14a and 14b open. Also the air intakes 9a and 9b are complete to the piston pockets 14a and 14b open. Via the air inlet openings 9a , 9b becomes air from the air duct 10 via the piston pockets 14a and 14b through the overflow window 13th , 16 in the overflow ducts 12th and 15th sucked in. The mouth openings 71 and 72 as well as the mixture inlet opening 20th are completely to the crankcase interior 29 open. In the area of the top dead center of the piston 5 the mixture is in the combustion chamber 3rd ignited, causing the piston 5 in the direction of the crankcase interior 29 is accelerated.

On the downstroke of the piston 5 first is the connection of the air intakes 9a and 9b with the piston pockets 14a and 14b interrupted. Then the connection of the overflow window 13th and 16 to the piston pockets 14a and 14b interrupted, and the mixture inlet opening 20th will be closed. With a further downward stroke of the piston 5 first becomes the mouth opening 71 and then the mouth opening 72 from the descending piston 5 locked. The outlet 11 from the combustion chamber 3rd begins to open, removing exhaust gases from the combustion chamber 3rd can flow out. With a further downward stroke of the piston 5 the overflow windows begin 13th and 16 to open. The second mouth opening 72 is already off the piston at this point 5 closed. The ones in the overflow ducts 12th and 15th upstream air flushes exhaust gases out of the combustion chamber 3rd out. These leave the combustion chamber 3rd through the outlet opening 11 .

The second mouth opening 72 is on the upstroke of the piston 5 preferably already over a crankshaft angle of at least 30 °, in particular at least 40 ° to the crankcase interior 29 open when the at least one overflow channel 12th , 15th with the air duct 10 is connected. This ensures that there is a sufficiently large negative pressure at the first drainage opening over a sufficiently long period of time 73 is applied before the negative pressure from the crankcase interior 29 at the air duct opening 9 is present.

The first mouth opening 71 is on the upstroke of the piston 5 preferably opened over a crankshaft angle of less than 30 °, in particular less than 20 °, before the mixture inlet opening 20th is opened to the crankcase interior.

The cross section of the drainage channels 51 and 52 is significantly smaller than the flow cross-section of the air duct 10 and mixture duct 21 . The cross section of the drainage channels is advantageous 51 and 52 less than 20%, in particular less than 10% of the flow cross section of the air duct 10 or the mixture channel 21. Due to the small flow cross-section, the drainage channels are 51 and 52 particularly active at low speeds, for example when idling. Fuel that collects in the air duct can particularly occur when the internal combustion engine is idling and when the engine is cold 1 Too unsteady running until the combustion engine goes out 1 as the fuel flows through the transfer channels 12th and 15th directly into the combustion chamber 3rd without first entering the crankcase interior 29 to have been processed. The combustion engine heats up at high speeds 1 fast, and the engine running is more stable due to the inertial masses, so that at high engine speeds the discharge of accumulated fuel is less critical. The drainage channels are due to the small flow cross-sections 51 and 52 largely ineffective at high speeds. As a result, the control times are not or only slightly influenced, so that low exhaust gas values can be achieved.

In the exemplary embodiment is the connecting flange 45 a comparatively massive component, which is preferably made of dimensionally stable plastic. A design made of metal, in particular made of light metal, can also be provided. In an alternative design, the connecting flange 45 Also be designed as an elastic, thin-walled connecting flange, preferably as a connecting piece made of an elastomer or the like.

In an alternative design it can be provided that the first mouth opening 71 and the second orifice 72 at least partially, in particular completely at the same time as the crankcase interior 29 are open. In 9 is a corresponding alternative position for a second orifice with a dashed line 72 ' drawn.

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• US 2013/0098325 A1 [0002]
• DE 10143435 A1 [0003]

Claims (21)

Connecting flange for connecting an air filter (41) to an internal combustion engine (1), an air duct (10) and a mixture duct (21) being guided separately from one another in the connecting flange (45), the connecting flange (45) having an end face (47) , wherein the section of the air channel (10) guided in the connecting flange (45) and the section of the mixture channel (21) guided in the connecting flange (45) open out at the end face (47), characterized in that the connecting flange (45) has a first drainage channel ( 51) for the mixture channel (21), which forms a connection between the mixture channel (21) and a first connection area (78, 78 '), and that the connecting flange (45) has a second drainage channel (52) for the air channel (10) which forms a connection formed separately from the first drainage channel (51) between the air channel (10) and a second connection area (79, 79 '). Connecting flange according to Claim 1 , characterized in that at least one drainage channel (51, 52) is connected to the mixture channel (21) or to the air channel (10) via at least one drainage opening (73, 74, 75). Connecting flange according to Claim 2 , characterized in that at least one drainage opening (73, 74, 75) is formed on the end face (69) on the connecting flange (45). Connecting flange according to Claim 3 , characterized in that at least one connection area (78, 79) is arranged on the end face (69). Connecting flange according to Claim 4 , characterized in that at least one drainage channel (51, 52) from the drainage opening (73, 74, 75) to the connection area (78, 79) is formed as a recess (58, 59) on the end face (69) of the connection flange (45) is. Connecting flange according to Claim 4 or 5 , characterized in that the first connection area (78) is arranged on the end face (69) separately from the mixture channel (21). Connection flange according to one of the Claims 4 to 6th , characterized in that the second connection area (79) is arranged on the end face (69) separately from the air duct (10). Connection flange according to one of the Claims 4 to 7th , characterized in that the second drainage channel (52) is designed as an annular channel. Connection flange according to one of the Claims 4 to 8th , characterized in that the first connection area (78) and the second connection area (79) are arranged on the side of the mixture channel (21) facing away from the air channel (10). Connection flange according to one of the Claims 4 to 8th , characterized in that the second connection area (79) is arranged on the side of the first connection area (78) facing away from the mixture duct (21). Connecting flange according to Claim 2 or 3rd , characterized in that at least one connection area (78 ', 79') is arranged on a circumferential side (76) of the connecting flange (45). Connection flange according to one of the Claims 1 to 11 , characterized in that the second drainage channel (52) opens into the air channel (10) with at least two drainage openings (74, 75). Connection flange according to one of the Claims 1 to 12th , characterized in that the end face (69) is provided for connection to a cylinder connection flange (60) of a cylinder (2) of an internal combustion engine (1). Cylinder for an internal combustion engine, in which a cylinder bore (26) is formed, with at least one overflow duct (12, 15), with a mixture duct (21) for supplying the fuel / air mixture and with an air duct (10) for supplying of flushing air can be connected to at least one overflow channel (12, 15), characterized in that the cylinder (2) has a first drainage channel (51) for the mixture channel (21), and that the cylinder (2) has a second drainage channel (52) for the air duct (10) which is guided in the cylinder (2) separately from the first drainage duct (51). Cylinder after Claim 14 , characterized in that the cylinder (2) has a cylinder connection flange (60) on which a first connection opening (61) for the first drainage channel (51) and a second connection opening (62) for the second drainage channel (52) are formed. Internal combustion engine with a cylinder (2) in which a cylinder bore (26) is formed, a piston (5) being guided to be movable back and forth in the cylinder bore (26), the piston (5) having a cylinder (2) formed combustion chamber (3), the piston (5) driving a crankshaft (7) rotatably mounted in a crankcase (4), with at least one overflow channel (12, 15), which in at least one position of the piston (5) has an in Crankcase (4) formed crankcase interior (29) connects to the combustion chamber (3), with a mixture duct (21) for supplying a fuel / air mixture into the crankcase interior (29), and with an air duct (10) which is connected to at least one overflow duct (12, 15) in at least one position of the piston (5) for the supply of flushing air, characterized in that the internal combustion engine (1) has a first drainage duct (51) , which connects the mixture channel (21) with the crankcase interior (29) in at least one position of the piston (5), the first drainage channel (51) opening with a first opening (71) into the crankcase interior (29), and that a second Drainage channel (52) is provided which connects the air channel (10) with the crankcase interior (29) in at least one position of the piston (5). Internal combustion engine after Claim 16 , characterized in that the first drainage channel (51) and the second drainage channel (52) open into the crankcase interior (29) with different mouth openings (71, 72). Internal combustion engine after Claim 16 or 17th , characterized in that at least one mouth opening (71, 72) of a drainage channel (51, 52) is controlled by the piston (5). Internal combustion engine after Claim 18 , characterized in that both mouth openings (71, 72) are controlled by the piston (5). Internal combustion engine after Claim 19 , characterized in that the orifices (71, 72) are arranged on the cylinder bore (26) in such a way that they open into the crankcase interior (29) during the upward stroke of the piston (5) at different control times. Internal combustion engine after Claim 20 , characterized in that the orifices (71, 72) are arranged on the cylinder bore (26) that the second orifice (72) of the second drainage channel (52) on the upward stroke of the piston (5) in front of the first orifice (71) of the first drainage channel (51) is connected to the crankcase interior.

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