EP0251159B1 - Return line for leak gas from a crank case - Google Patents

Return line for leak gas from a crank case Download PDF

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Publication number
EP0251159B1
EP0251159B1 EP87109025A EP87109025A EP0251159B1 EP 0251159 B1 EP0251159 B1 EP 0251159B1 EP 87109025 A EP87109025 A EP 87109025A EP 87109025 A EP87109025 A EP 87109025A EP 0251159 B1 EP0251159 B1 EP 0251159B1
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EP
European Patent Office
Prior art keywords
return conduit
cylinder head
opening
return line
intake
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
EP87109025A
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German (de)
French (fr)
Other versions
EP0251159A2 (en
EP0251159A3 (en
Inventor
Herbert Schleiermacher
Reinhard Rechberg
Lothar Bauer
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Kloeckner Humboldt Deutz AG
Original Assignee
Kloeckner Humboldt Deutz AG
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Filing date
Publication date
Priority claimed from DE19863622024 external-priority patent/DE3622024A1/en
Priority claimed from DE19873704567 external-priority patent/DE3704567A1/en
Application filed by Kloeckner Humboldt Deutz AG filed Critical Kloeckner Humboldt Deutz AG
Publication of EP0251159A2 publication Critical patent/EP0251159A2/en
Publication of EP0251159A3 publication Critical patent/EP0251159A3/en
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Publication of EP0251159B1 publication Critical patent/EP0251159B1/en
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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
    • F02B75/00—Other engines
    • F02B75/16—Engines characterised by number of cylinders, e.g. single-cylinder engines
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01M—LUBRICATING OF MACHINES OR ENGINES IN GENERAL; LUBRICATING INTERNAL COMBUSTION ENGINES; CRANKCASE VENTILATING
    • F01M13/00—Crankcase ventilating or breathing
    • 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
    • F02B2075/027—Engines characterised by their cycles, e.g. six-stroke having less than six strokes per cycle four
    • 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
    • F02B3/00—Engines characterised by air compression and subsequent fuel addition
    • F02B3/06—Engines characterised by air compression and subsequent fuel addition with compression ignition

Definitions

  • the invention relates to a return line for leak gases from the crankcase of a four-stroke internal combustion engine into the intake pipes of the cylinders.
  • the recirculation of the leakage gases has a positive side effect, especially with diesel engines.
  • the leakage gases returned to the intake pipes take oil droplets out of the crankcase. These finely divided, entrained oil droplets are sufficient to lubricate the valve seats of the intake valves and to protect them from wear. This is much more advantageous than if lubrication along the valve stems were caused by seeping oil. Because of the heat acting on the valve stem there is a risk that the oozing oil cokes on the valve stems and thus narrows the cross section of the intake pipe.
  • the invention has set itself the task of distributing the leakage gases evenly over each cylinder in such a way that sufficient lubrication of the valve seats of all intake valves is ensured.
  • the return line is advantageously connected to each intake pipe of a cylinder via an opening. This ensures that each of the cylinders can suck in leakage gases and thus its inlet valves are adequately lubricated in the valve seats.
  • the different diameters of the orifices in the return line as seen in the direction of flow of the leak gases, so that the last orifice has a much larger diameter and a different exit direction into the intake pipe than the first orifice, ensure that each cylinder is the same Amount of leak gases can be sucked in. According to the flow laws, the area of an opening and the direction of its exit can directly influence the amount of gas flowing through this opening per unit of time.
  • the cylinder lying first in the flow direction of the return line sucks in the leakage gases from the smallest opening.
  • the leakage gases still contain the highest proportion of oil mist in this part of the return line.
  • the amount of leakage gases and their oil mist content decrease in the return line from intake pipe to intake pipe.
  • the last opening in the return line viewed in the direction of flow of the leakage gases, is considerably larger than the first.
  • the openings are arranged in a spiral or almost spiral line around the return line, the first opening as seen in the flow direction of the return line being on the side facing away from the suction opening of the suction pipe and the last one being on the side of the return line facing the suction opening of the suction pipe .
  • This arrangement of the holes advantageously prevents oil from dripping through a vertically downward opening at the point where the leakage gases have the highest content of oil mist and oil droplets can precipitate on the wall, get into the intake port of the cylinder and for an oversupply of oil. Even if oil droplets are deposited at the location of the first hole, only oil mist with the leakage gases gets into the intake pipe of the cylinder. Since the number of cylinders causes the leakage gases to become less oil-rich, the openings can also be turned towards the intake manifold. At the last intake pipe, the leak gases have already become so low in oil mist that there is no danger that larger oil drops will separate.
  • the openings in the return line have a nozzle-like extension toward the outside. This configuration of the openings advantageously ensures that the leakage gases flow out uniformly and thus the oil mist is evenly distributed in the intake air of the intake pipes.
  • the return line is used as a separate tube in the intake box.
  • This design is advantageously used when the intake box is flanged to the cylinder head of the internal combustion engine as a separate component, for example made of plastic.
  • the Return line as a straight line along the intake ports in the cylinder head and the openings open directly into the intake ports leading to the intake valves.
  • the space requirement for the return line is limited to a minimum and the number of attachments is reduced.
  • the cylinder head cover is formed in one piece and the return line is integrated into the cylinder head cover.
  • the cylinder head is composed of single cylinder heads and the return line is integrated into the single cylinder heads or also into the single cylinder head covers.
  • a continuous return line is formed by connecting pieces arranged between the individual cylinder heads.
  • the return line is expediently designed as a bore or is left out when the cylinder head is cast.
  • the return line can also, for. B. are cast as a tube in the cylinder head or the cylinder head.
  • the return line advantageously runs through the entire length of the cylinder head and is arranged in the immediate vicinity of the intake pipes in order to achieve a short connecting line from the return line to the intake pipes.
  • These connecting channels are expediently designed as bores or as throttle screw plugs.
  • the connecting channels expediently open into the return line at the geodetically lowest point.
  • the flow cross-section of the connecting channels in the flow direction of the returned leakage gases is expediently formed.
  • the intake pipes advantageously protrude from the cylinder head base plate at an angle of approximately 30 ° .
  • a supply line for the return line is advantageously incorporated into the cylinder head.
  • FIG. 1 The intake box of a four-cylinder four-stroke diesel engine is shown in the open state. The view is from the air filter side.
  • the housing of the intake box 1 is fastened to the respective cylinder heads, which are not shown here, with fastening tabs 2.
  • the four intake pipes 3 can be seen in the top view. They are inclined with their intake openings 3 "to the left and below the intake box the flanges 4 can be seen for connection to the intake port of the respective cylinder.
  • the return line 6 for the leak gases is led to the crankcase from a connecting piece 5.
  • the return line 6 is located as a pipe inside the intake box I above the intake pipes 3.
  • the return line 6 is fastened to the housing of the intake box I with a screw connection 7.
  • each suction pipe 3 there is an opening 8 in the return line 6. These openings 8 are located on an almost spiral line around the center line 9 of the return line 6.
  • the opening is very small compared to the subsequent openings, which are each rotated by several degrees in the direction of the intake openings of the intake pipes 3, so that the last opening above the last suction pipe points vertically downwards, directly in the direction of the suction opening 3 "of the suction pipe 3. This opening is the largest of all four openings shown.
  • the arrangement of the holes 8 on the return line 6 thus ensures that when entering the intake box I only Oil mist is sucked in by the first suction pipe 3 and that the last suction pipe can also suck in the same amount of leakage gases with the same amount of oil.
  • Tubes can also be inserted into the openings of the return line. If the tubes all have the same cross-section, an opening of any shape and size can be formed by pressing the end together. By bending the pipes, the openings can be rotated as desired in the area of the suction openings of the suction pipes.
  • Fig. 2 shows a section through the intake box I with a view of the intake opening 3 "of an intake pipe 3.
  • the intake pipe 3 opens upwards towards the viewer, while it opens into the intake port of the cylinder at the bottom left of flange 4.
  • return line 6 runs clearly.
  • An opening 8 can be seen clearly, which passes through at an angle of approximately 45 ° to the vertical the center line 9 is directed downward onto the suction opening 3 ′′ of the suction pipe 3.
  • the opening 8 has a nozzle-shaped extension 10 towards the outside.
  • This shape of the opening ensures a uniform outflow of the leakage gases and an optimal fanning out of the emerging jet of leakage gases and oil mist, so that there is good mixing with the air sucked in by the suction pipe 3.
  • the processing of the openings 8 must be done very carefully so that no burrs and unevenness arise. This could namely have a very strong influence on the flow, so that the leakage gases would be distributed unevenly.
  • the intake pipe shown is the penultimate one of the exhaust pipes shown in FIG.
  • the return line 6 can also be shielded from the upstream air filter by a short, downward-reaching, sheet metal plate (not shown here). This can prevent, depending on the position of the openings 8, the upstream filter from being wetted by oil mist.
  • the diameter of the respective openings 8 in the return line 6 increases continuously in the same steps, as seen in the flow direction of the leak gases. If it is advantageous for the flow conditions due to the design, two successive holes can also have the same diameter.
  • the selected angular misalignment of the holes on the circumference of the return line 6 does not take place in angular steps of the same size.
  • two successive holes can be located at the same point on the circumference, at the same angular degree.
  • the return line 6 is incorporated directly into the cylinder head 10.
  • the return line 6 is designed as a straight-line channel, which is cut out directly in the casting process of the cylinder head 2 by a corresponding casting core or is subsequently worked into the cylinder head 10 by, for example, drilling.
  • the return line 6 is arranged above the intake ducts II and the openings 8 open directly into the housing walls of the intake ducts II.
  • the alignment of the openings 8 in the intake ducts II is carried out analogously to the explanations as described in FIGS. I and 2.
  • the supply line, from which the return line 6 is supplied with leakage gases and oil mist, is advantageously incorporated into the cylinder head 10 in this embodiment and connected to the crankcase of the internal combustion engine via corresponding lines and possibly valves.
  • FIGS. 4 and 5 show the different openings of the openings 8 into the intake ducts II of the cylinder head 10, reference being made to the description of the drawing relating to FIGS. I and 2 with regard to the orientation of the openings 8.
  • the return line 6 according to the invention can be used in all types of four-stroke internal combustion engines.
  • three-, five-, six- and multi-cylinder engines are suitable for the application of the invention.
  • FIG. 6 shows a section of a cylinder head 3 'of a four-stroke internal combustion engine with an integrated return line for leak gases.
  • An intake pipe 2 'or an inlet duct for the combustion gases is arranged at an angle of approximately 30 ° from the cylinder head base plate 9'.
  • the intake pipe 2 ' is connected to a combustion chamber (not shown) via an inlet valve 10'.
  • the inlet valve 10 ' can be acted upon by a rocker arm II' against the force of a spring 12 ', the other end, not shown, of the rocker arm II' being operatively connected to the camshaft or the tappet tube of the engine.
  • the rocker arm 11 'together with the spring 12' is covered by a cylinder head cover 5 'which is connected to the cylinder head 3' via a seal 13 '.
  • the cylinder head 3 ' is designed as a block cylinder head or as a single cylinder head and in the cylinder head 3' there is a return line 4 'running through the entire length of the head, ie the return line 4' is integrated in the cylinder head 3 '.
  • the continuous return line 4' is formed by connecting pieces arranged between the cylinder heads 3 '. As connectors are z. B. Double plug-in pieces are ideally suited.
  • the return line 4 ' is arranged in the immediate vicinity of the intake pipes 2' and is either designed as a bore or cast in or recessed in the mold.
  • the return line 4' is connected to the intake pipes 2 'via connecting channels 8'. It is ever a connecting duct 8 'is assigned to the intake pipe or inlet duct.
  • the connecting channels 8' advantageously open into the return line 4 'at the geodetically lowest point.
  • the connecting channels 8 ' can advantageously be designed as bores or as throttle screw plugs 5'.
  • the size of the connecting duct 8 'or its position relative to the intake pipe 2' expediently differs depending on the number of engine cylinders.
  • the flow cross section of the connecting channels 8' in the flow direction of the returned gases is expediently formed.
  • the connecting channels -8 ' are introduced into the return line 4' starting from the inside of the intake pipes 2 '. This eliminates the need for additional closure parts that would be necessary if the connecting channels 8 'were introduced from the outside.
  • a recess 14 ' is arranged between the connecting duct 8' and the intake pipe 2 'and serves for better attachment of the connecting duct 8'.
  • Fig. 7 shows an alternative embodiment in which the cylinder head cover 5 'is formed in one piece and the return line 4' is integrated in the cylinder head cover.
  • the cylinder head cover 5 ' is flanged to the cylinder head 3' with the interposition of seals 13 '.
  • a connecting duct 8 ' leads from the return line 4' in the direction of the seam between the cylinder head cover and the cylinder head and is designed as described in FIG. 6.
  • the connecting channel 8 ' can easily be introduced into the cylinder head cover 5' before it is installed.
  • the connecting duct 8 ' is connected to the intake pipe 2' via a further connecting duct 8 'with a larger diameter.
  • the arrangement of the return line 4 'in the region of the steeply rising intake pipes 2' or inlet channels prevents the formation of oil sump or an oil deposit in the air intake housing or in the intake pipe 2 '. Even with extreme engine inclinations, the oil drain is guaranteed by the 30 ° angle of attack of the intake pipe 2 'to the cylinder head base 9' (see FIG. 6), in the direction of the valve seat 15 '.
  • Fig. 8 shows a view Fig. 8a and a section of a breather valve housing 7 'arranged on the engine.
  • This vent valve housing 7 ' is part of the return line. It can be seen that the return line 4 'directly via sealing elements 6' z. B. a round seal is flanged to the vent valve housing 7 '.
  • the vent valve housing 7 ' is in turn connected directly to the crankcase.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Lubrication Details And Ventilation Of Internal Combustion Engines (AREA)

Description

Die Erfindung betrifft eine Rückführleitung für Leckgase aus dem Kurbelgehäuse eines Viertakt-Verbrennungsmotors in die Ansaugrohre der Zylinder.The invention relates to a return line for leak gases from the crankcase of a four-stroke internal combustion engine into the intake pipes of the cylinders.

Beim Viertakt-Verfahren eines Verbrennungsmotors gelangen bei den Takten des Verdichtens und Verbrennens Gase an den Kolben vorbei in das Kurbelgehäuse. Der Grund liegt darin, daß die Kolbenringe nie eine hundertprozentige Abdichtung zwischen Zylinder und Kurbelgehäuse herstellen können. Deshalb gelangen sog. Leckgase ins Kurbelgehäuse, die teils aus unverbranntem Luft-Kraftstoff-Gemisch, teils aus den Verbrennungsgasen bestehen. Während früher das Kurbelgehäuse in die Umgebung entlüftet wurde, ist heutzutage aus Gründen des Umweltschutzes eine Rückführung der Leckgase erforderlich. Die Rückführung erfolgt bei Viertakt-Benzinmotoren in der Regel hinter dem Luftfilter in das Ansaugrohr des Vergasers, bei Viertakt-Diesemotoren hinter dem Luftfilter vor die Ansaugrohre der Zylinder.In the four-stroke process of an internal combustion engine, gases pass the pistons and into the crankcase during the compression and combustion cycles. The reason is that the piston rings can never create a 100% seal between the cylinder and crankcase. So-called leakage gases enter the crankcase, which partly consist of an unburned air-fuel mixture and partly of the combustion gases. While the crankcase was previously vented to the environment, it is now necessary to recycle the leakage gases for environmental reasons. With four-stroke petrol engines, the return is usually behind the air filter in the intake pipe of the carburetor, with four-stroke diesel engines behind the air filter in front of the intake pipes of the cylinders.

Die Rückführung der Leckgase hat vor allem bei Dieselmotoren einen positiven Nebeneffekt. Die vor die Ansaugrohre rückgeführten Leckgase reißen nämlich Öltröpfchen aus dem Kurbelgehäuse mit. Diese feinverteilten, mitgerissenen Oltröpfchen genügen, um die Ventilsitze der Einlaßventile zu schmieren und vor Verschleiß zu schützen. Dieses ist wesentlich vorteilhafter, als wenn eine Schmierung entlang der Ventilschäfte durch herabsickerndes Öl erfolgen würde. Aufgrund der Wärmeeinwirkung auf den Ventilschaft besteht nämlich die Gefahr, daß das herabsickernde Öl an den Ventilschäften verkokt und damit den Querschnitt des Ansaugrohrs verengt.The recirculation of the leakage gases has a positive side effect, especially with diesel engines. The leakage gases returned to the intake pipes take oil droplets out of the crankcase. These finely divided, entrained oil droplets are sufficient to lubricate the valve seats of the intake valves and to protect them from wear. This is much more advantageous than if lubrication along the valve stems were caused by seeping oil. Because of the heat acting on the valve stem there is a risk that the oozing oil cokes on the valve stems and thus narrows the cross section of the intake pipe.

Werden die Leckgase aber unkontrolliert vor die Ansaugrohre der Zylinder über eine einzige Öffnung rückgeführt, besteht die Gefahr, daß der Zylinder, dem die Öffnung der Rückführleitung am nächsten liegt, die meisten Leckgase ansaugt, und daß der am entferntesten liegende Zylinder keine Leckgase mehr ansaugen kann. Das führt naturgemäß zu einer ungleichmäßigen Verteilung des Ölnebels auf die einzelnen Zylinder, so daß sich die Einlaßventile der Zylinder, die den meisten Ölnebel ansaugen, mit Ölkohle zusetzen, während bei Ventilen der Zylinder, die keine Leckgase mehr ansaugen, wegen mangelnder Schmierung Ventilschäden durch Ventilsitzverschleiß auftreten.However, if the leakage gases are returned in an uncontrolled manner in front of the intake pipes of the cylinders through a single opening, there is a risk that the cylinder which is closest to the opening of the return line will suck in most of the leakage gases and that the most distant cylinder will no longer be able to suck in leakage gases . This naturally leads to an uneven distribution of the oil mist to the individual cylinders, so that the inlet valves of the cylinders that draw in most of the oil mist are clogged with oil carbon, while in the case of valves of the cylinders that no longer suck in leakage gases, valve damage due to insufficient seat lubrication occurs due to insufficient lubrication occur.

Um die Nachteile dieser unkontrollierten Leckgasrückführung zu vermeiden, hat die Erfindung sich die Aufgabe gestellt, die Leckgase so gleichmäßig auf jeden Zylinder zu verteilen, daß eine ausreichende Schmierung der Ventilsitze aller Einlaßventile gewährleistet ist.In order to avoid the disadvantages of this uncontrolled leakage gas recirculation, the invention has set itself the task of distributing the leakage gases evenly over each cylinder in such a way that sufficient lubrication of the valve seats of all intake valves is ensured.

Die Aufgabe wird mit Hilfe der kennzeichnenden Merkmale des Anspruchs I gelöst.The object is achieved with the aid of the characterizing features of claim I.

In vorteilhafter Weise steht die Rückführleitung mit jedem Ansaugrohr eines Zylinders über eine Öffnung in Verbindung. Dadurch ist gewährleistet, daß jeder der Zylinder Leckgase ansaugen kann und damit seine Einlaßventile eine genügende Schmierung in den Ventilsitzen erfahren. Die unterschiedlichen Durchmesser der Öffnungen, die sich in Strömungsrichtung der Leckgase gesehen in der Rückführleitung, so ändern, daß die letzte Öffnung einen wesentlich größeren Durchmesser und eine andere Austrittsrichtung in das Ansaugrohr aufweist als die erste Öffnung, stellen sicher, daß von jedem Zylinder die gleiche Menge Leckgase angesaugt werden kann. Nach den Strömungsgesetzen kann über die Fläche einer Öffnung sowie über die Richtung ihres Austritts direkt auf die pro Zeiteinheit durch diese Öffnung strömende Gasmenge Einfluß genommen werden. Der in Strömungsrichtung der Rückführleitung gesehen erstliegende Zylinder saugt die Leckgase aus der kleinsten Öffnung an. In diesem Teil der Rückführleitung enthalten die Leckgase noch den höchsten Ölnebelanteil. Die Menge der Leckgase und ihr Ölnebelanteil nimmt aber in der Rückführleitung von Ansaugrohr zu Ansaugrohr ab. Um alle Zylinder gleichmäßig mit Leckgasen zu versorgen und dadurch eine Schmierung der Ventilsitze der Einlaßventile sicherzustellen, ist die in Strömungsrichtung der Leckgase gesehen letzte Öffnung in der Rückführleitung wesentlich größer als die erste.The return line is advantageously connected to each intake pipe of a cylinder via an opening. This ensures that each of the cylinders can suck in leakage gases and thus its inlet valves are adequately lubricated in the valve seats. The different diameters of the orifices in the return line, as seen in the direction of flow of the leak gases, so that the last orifice has a much larger diameter and a different exit direction into the intake pipe than the first orifice, ensure that each cylinder is the same Amount of leak gases can be sucked in. According to the flow laws, the area of an opening and the direction of its exit can directly influence the amount of gas flowing through this opening per unit of time. The cylinder lying first in the flow direction of the return line sucks in the leakage gases from the smallest opening. The leakage gases still contain the highest proportion of oil mist in this part of the return line. However, the amount of leakage gases and their oil mist content decrease in the return line from intake pipe to intake pipe. In order to supply all cylinders with leakage gases evenly and thereby ensure lubrication of the valve seats of the inlet valves, the last opening in the return line, viewed in the direction of flow of the leakage gases, is considerably larger than the first.

In Ausgestaltung der Erfindung sind die Öffnungen in einer spiralförmigen oder nahezu spiralförmigen Linie um die Rückführleitung angeordnet, wobei die in Strömungsrichtung der Rückführleitung gesehen erste Öffnung auf der der Ansaugöffnung des Ansaugrohrs abgewandten Seite und die letzte auf der der Ansaugöffnung des Ansaugrohrs zugewandten Seite der Rückführleitung liegen. Diese Anordnung der Löcher verhindert vorteilhaft, daß an der Stelle, wo die Leckgase den höchsten Gehalt an Ölnebel aufweisen und sich Öltröpfchen an der Wandung niederschlagen können, durch eine senkrecht nach unten weisende Öffnung Öl heraustropft, in den Ansaugstutzen des Zylinders gelangt und fur ein Überangebot an Öl sorgt. Selbst wenn sich an der Stelle des ersten Lochs Öltröpfchen abscheiden sollten, gelangt doch nur Ölnebel mit den Leckgasen in das Ansaugrohr des Zylinders. Da mit zunehmender Anzahl der Zylinder die Leckgase ölärmer werden, können auch die Öffnungen entsprechend zu den Ansaugstutzen hin gedreht werden. Am letzten Ansaugrohr sind die Leckgase bereits so ölnebelarm geworden, daß keine Gefahr besteht, daß sich größere Öltropfen abscheiden.In an embodiment of the invention, the openings are arranged in a spiral or almost spiral line around the return line, the first opening as seen in the flow direction of the return line being on the side facing away from the suction opening of the suction pipe and the last one being on the side of the return line facing the suction opening of the suction pipe . This arrangement of the holes advantageously prevents oil from dripping through a vertically downward opening at the point where the leakage gases have the highest content of oil mist and oil droplets can precipitate on the wall, get into the intake port of the cylinder and for an oversupply of oil. Even if oil droplets are deposited at the location of the first hole, only oil mist with the leakage gases gets into the intake pipe of the cylinder. Since the number of cylinders causes the leakage gases to become less oil-rich, the openings can also be turned towards the intake manifold. At the last intake pipe, the leak gases have already become so low in oil mist that there is no danger that larger oil drops will separate.

In weiterer Ausgestaltung der Erfindung weisen die Öffnungen in der Rückführleitung nach außen hin eine düsenförmige Erweiterung auf. Durch diese Ausgestaltung der Öffnungen wird vorteilhaft sichergestellt, daß die Leckgase gleichmäßig ausströmen und sich damit der Olnebel gleichmäßig in der angesaugten Luft der Ansaugrohre verteilt.In a further embodiment of the invention, the openings in the return line have a nozzle-like extension toward the outside. This configuration of the openings advantageously ensures that the leakage gases flow out uniformly and thus the oil mist is evenly distributed in the intake air of the intake pipes.

In Weiterbildung der Erfindung ist die Rückführleitung als separates Rohr in den Ansaugkasten eingesetzt. Diese Ausbildung wird vorteilhaft dann angewendet, wenn der Ansaugkasten als separates beispielsweise aus Kunststoff gefertigtes Bauteil an den Zylinderkopf des Verbrennungsmotors angeflanscht ist. Es ist auch erfindungsgemäß vorgesehen, die Rückführleitung direkt in den Zylinderkopf einzuarbeiten bzw. zu integrieren. In dieser erfindungsgemäßen Ausgestaltung erstreckt sich die Rückführleitung als geradliniger Kanal entlang der Ansaugkanäle in dem Zylinderkopf und die Öffnungen münden direkt in die zu den Einlaßventilen führenden Ansaugkanäle.In a development of the invention, the return line is used as a separate tube in the intake box. This design is advantageously used when the intake box is flanged to the cylinder head of the internal combustion engine as a separate component, for example made of plastic. It is also provided according to the invention to incorporate or integrate the return line directly into the cylinder head. In this embodiment according to the invention, the Return line as a straight line along the intake ports in the cylinder head and the openings open directly into the intake ports leading to the intake valves.

Durch die erfindungsgemäße Integrierung der Rückführleitung in den Blockzylinderkopf oder den Einzelzylinderkopf ist der Platzbedarf für die Rückführleitung auf ein Minimum beschränkt und die Zahl der Anbauteile verrringert.By integrating the return line into the block cylinder head or the single cylinder head according to the invention, the space requirement for the return line is limited to a minimum and the number of attachments is reduced.

In einer vorteilhaften Ausführungsform ist die Zylinderkopfhaube einteilig ausgebildet und die Rückführleitung in die Zylinderkopfhaube integriert.In an advantageous embodiment, the cylinder head cover is formed in one piece and the return line is integrated into the cylinder head cover.

In einer alternativen Ausführungsform ist der Zylinderkopf aus Einzelzylinderköpfen zusammengesetzt und die Rückführleitung in die Einzelzylinderköpfe oder auch in die Einzelzylinderkopfhauben integriert. Dabei ist durch zwischen den Einzelzylinderköpfen angeordnete Verbindungsstücke eine durchgehende Rückführleitung gebildet.In an alternative embodiment, the cylinder head is composed of single cylinder heads and the return line is integrated into the single cylinder heads or also into the single cylinder head covers. In this case, a continuous return line is formed by connecting pieces arranged between the individual cylinder heads.

Die Rückfuhrleitung ist in allen Ausführungsformen zweckmäßigerweise als Bohrung ausgebildet oder aber beim Gießen des Zylinderkopfes ausgespart. Ferner kann die Rückführleitung auch z. B. als Rohr in den Zylinderkopf bzw. die Zylinderkopfhabe eingegossen werden.In all of the embodiments, the return line is expediently designed as a bore or is left out when the cylinder head is cast. Furthermore, the return line can also, for. B. are cast as a tube in the cylinder head or the cylinder head.

Damit die Leckgase auf alle Zylinder verteilt werden können, durchzieht vorteilhafterweise die Rückführleitung die ganze Länge des Zylinderkopfes und ist jeweils in unmittelbarer Nachbarschaft der Ansaugrohre angeordnet, um eine kurze Verbindungsleitung von der Rückführleitung zu den Ansaugrohren zu erreichen. Diese Verbindungskanäle sind zweckmäßigerweise als Bohrungen oder als Drosselschraubstopfen ausgebildet. Zur Vermeidung eines Ölsumpfes in der Rückführleitung münden zweckmäßigerweise die Verbindungskanäle an geodätisch tiefster Stelle in die Rückführleitung. Damit, in Strömungsrichtung gesehen, alle Zylinder die gleiche Menge an Leckgasen zugeführt bekommen, ist sinnvollerweise der Strömungsquerschnitt der Verbindungskanäle, in Strömungsrichtung der rückgeführten Leckgase, zunehmend ausgebildet.So that the leakage gases can be distributed to all cylinders, the return line advantageously runs through the entire length of the cylinder head and is arranged in the immediate vicinity of the intake pipes in order to achieve a short connecting line from the return line to the intake pipes. These connecting channels are expediently designed as bores or as throttle screw plugs. In order to avoid an oil sump in the return line, the connecting channels expediently open into the return line at the geodetically lowest point. In order that, in the flow direction, all cylinders receive the same amount of leakage gases, the flow cross-section of the connecting channels in the flow direction of the returned leakage gases is expediently formed.

Um ein Abfließen des in den Leckgasen enthaltenen Öls in die Zylinder auch bei Schräglage des Motors sicherzustellen, stehen die Ansaugrohre vorteilhafterweise in einem Winkel von ca. 30° von der Zylinderkopfbodenplatte ab.In order to ensure that the oil contained in the leakage gases flows into the cylinders even when the engine is in an inclined position, the intake pipes advantageously protrude from the cylinder head base plate at an angle of approximately 30 ° .

Weiterhin ist es zweckmäßig, die Rückführleitung unmittelbar über Dichtungselemente an ein Entlüftungsventilgehäuse anzuflanschen, um eine möglichst kompakte Bauform des Motors zu erreichen.Furthermore, it is expedient to flange the return line directly to a breather valve housing via sealing elements in order to achieve the most compact possible construction of the engine.

Vorteilhafterweise ist eine Versorgungsleitung für die Rückführleitung in den Zylinderkopf eingearbeitet.A supply line for the return line is advantageously incorporated into the cylinder head.

Weitere Merkmale der Erfindung ergeben sich aus der Beschreibung und den Figuren, die verschiedene Ausführungsformen der Erfindung zeigen und nachfolgend näher beschrieben sind.Further features of the invention result from the description and the figures, which show different embodiments of the invention and are described in more detail below.

Es zeigt:

  • Fig. I: den geöffneten Ansaugkasten eines Viertakt-Dieselmotors von der Luftfilterseite aus gesehen,
  • Fig. 2: einen Querschnitt durch diesen Ansaugkasten mit Blick auf ein Ansaugrohr,
  • Fig. 3: eine in den Zylinderkopf eingearbeitete Rückführleitung,
  • Fig. 4 u. 5: Querschnitte durch die Rückführleitung im Bereich der Öffnungen in die Ansaugkanäle,
  • Fig. 6: einen Ausschnitt aus einem Zylinderkopf mit integrierter Rückführleitng für Leckgase,
  • Fig. 7: einen Ausschnitt aus einem Zylinderkopf mit in die Zylinderkopfhaube integrierter Rückführleitung und
  • Fig. 8: eine Ansicht und einen Schnitt von einem am Motor angeordneten Entlüftungsventilgehäuse.
It shows:
  • I: the open intake box of a four-stroke diesel engine seen from the air filter side,
  • 2 shows a cross section through this intake box with a view of an intake pipe,
  • 3: a return line incorporated in the cylinder head,
  • Fig. 4 u. 5: cross sections through the return line in the area of the openings into the intake ducts,
  • 6: a section of a cylinder head with an integrated return line for leak gases,
  • Fig. 7: a section of a cylinder head with a return line integrated in the cylinder head cover and
  • 8: a view and a section of a vent valve housing arranged on the engine.

In Fig. ist der Ansaugkasten eines vierzylindrigen Viertakt-Dieselmotors in geöffnetem Zustand dargestellt. Die Ansicht erfolgt von der Luftfilterseite aus. Das Gehäuse des Ansaugkastens 1 wird mit Befestigungslaschen 2 an den jeweiligen Zylinderköpfen, die hier nicht näher dargestellt sind, befestigt. In dem Ansaugkasten I sind die vier Ansaugrohre 3 in der Aufsicht zu erkennen. Sie sind mit ihren Ansaugöffnungen 3" nach links geneigt und unterhalb des Ansaugkastens sind die Flansche 4 zum Anschluß an den Ansaugkanal des jeweiligen Zylinders zu sehen. Af der linken Seite wird von einem Anschlußstutzen 5 die Rückführleitung 6 für die Leckgase zum Kurbelgehäuse hingeführt. Die Rückführleitung 6 liegt als Rohr im Inneren des Ansaugkastens I oberhalb der Ansaugrohre 3. Mit einer Schraubverbindung 7 ist die Rückführleitung 6 an dem Gehäuse des Ansaugkastens I befestigt.In Fig. The intake box of a four-cylinder four-stroke diesel engine is shown in the open state. The view is from the air filter side. The housing of the intake box 1 is fastened to the respective cylinder heads, which are not shown here, with fastening tabs 2. In the intake box I, the four intake pipes 3 can be seen in the top view. They are inclined with their intake openings 3 "to the left and below the intake box the flanges 4 can be seen for connection to the intake port of the respective cylinder. On the left side, the return line 6 for the leak gases is led to the crankcase from a connecting piece 5. The return line 6 is located as a pipe inside the intake box I above the intake pipes 3. The return line 6 is fastened to the housing of the intake box I with a screw connection 7.

In Höhe der Ansaugöffnung 3" eines jeden Ansaugrohrs 3 ist in der Rückführleitung 6 jeweils eine Öffnung 8. Diese Öffnungen 8 befinden sich auf einer nahezu spiralförmigen Linie um die Mittellinie 9 der Rückführleitung 6. Am Anfang der Rückführleitung 6 in dem Ansaugkasten I befindet sich die Öffnung oberhalb des ersten Ansaugrohrs links nahezu auf der entgegengesetzten Seite von der Ansaugöffnung 3" des Ansaugrohrs 3. Außerdem ist die Öffnung sehr klein im Vergleich zu den darauf folgenden Öffnungen, die jeweils um mehrere Winkelgrade in Richtung auf die Ansaugöffnungen der Ansaugrohre 3 hingedreht sind, so daß die letzte Öffnung über dem letzten Ansaugrohr senkrecht nach unten weist, direkt in Richtung auf die Ansaugöffnung 3" des Ansaugrohrs 3 hin. Diese Öffnung ist die größte von allen vier dargestellten Öffnungen.At the level of the suction opening 3 ″ of each suction pipe 3 there is an opening 8 in the return line 6. These openings 8 are located on an almost spiral line around the center line 9 of the return line 6. At the beginning of the return line 6 in the suction box I there is the opening Opening above the first intake pipe on the left almost on the opposite side from the intake opening 3 "of the intake pipe 3. In addition, the opening is very small compared to the subsequent openings, which are each rotated by several degrees in the direction of the intake openings of the intake pipes 3, so that the last opening above the last suction pipe points vertically downwards, directly in the direction of the suction opening 3 "of the suction pipe 3. This opening is the largest of all four openings shown.

Werden sehr stark mit Olnebel beladene Leckgase aus dem Kurbelgehäuse angesaugt, besteht die Gefahr, daß sich Öltröpfchen in der Olleitung niederschlagen. Das ist besonders beim Eintritt der Rückführleitung in den Ansaugkasten I der Fall, wo die kalte, angesaugte Luft das Rohr umströmt. Wäre dort die Öffnung 8 direkt im Bereich der Ansaugöffnung 3" des Ansaugrohrs 3 nach unten gerichtet, würde die Gefahr bestehen, daß die abgeschiedenen Öltröpfchen in das erste Ansaugrohr hineingesaugt würden und somit ein Überangebot an 01 in dem darunterliegenden Ansaugrohr und damit an dem Einlaßventil anfiele, während beim letzten Ansaugrohr kein Öl mehr ankäme. Die Anordnung der Löcher 8 auf der Rückführleitung 6 stellt somit sicher, daß beim Eintritt in den Ansaugkasten I nur Ölnebel von dem ersten Ansaugrohr 3 angesaugt wird und daß auch das letzte Ansaugrohr die gleiche Menge Leckgase mit dem gleichen Ölanteil ansaugen kann. In die Öffnungen der Rückführleitung können auch Röhrchen gesteckt werden. Weisen die Röhrchen alle den gleichen Querschnitt auf, kann durch Zusammendrücken des Endes eine Öffnung beliebiger Form und Größe geformt werden. Durch Biegen der Rohre können die Öffnungen beliebig in den Bereich der Ansaugöffnungen der Ansaugrohre gedreht werden.If leakage gases heavily loaded with oil mist are sucked out of the crankcase, there is a risk of oil droplets being deposited in the oil line. This is particularly the case when the return line enters intake box I, where the cold, intake air flows around the pipe. If the opening 8 were directed downward directly in the area of the suction opening 3 "of the suction pipe 3, there would be the danger that the separated oil droplets would be sucked into the first suction pipe and thus an oversupply of 01 would occur in the suction pipe underneath and thus at the inlet valve , while no more oil would arrive at the last intake pipe. The arrangement of the holes 8 on the return line 6 thus ensures that when entering the intake box I only Oil mist is sucked in by the first suction pipe 3 and that the last suction pipe can also suck in the same amount of leakage gases with the same amount of oil. Tubes can also be inserted into the openings of the return line. If the tubes all have the same cross-section, an opening of any shape and size can be formed by pressing the end together. By bending the pipes, the openings can be rotated as desired in the area of the suction openings of the suction pipes.

Fig. 2 zeigt einen Schnitt durch den Ansaugkasten I mit Blick auf die Ansaugöffnung 3" eines Ansaugrohrs 3. Auf der rechten Seite des Ansaugkastens I muß man sich den Luftfilter ergänzt denken, während die Befestigungslasche 2 mit dem zugehörigen Zylinderkopf verschraubt ist. Das Ansaugrohr 3 öffnet sich nach oben zum Betrachter hin, während es unten links am Flansch 4 in den Ansaugstutzen des Zylinders mündet. Oberhalb des Ansaugrohrs 3 verläuft die Rückführleitung 6. Deutlich zu erkennen ist eine Öffnung 8, die unter einem Winkel von etwa 45 0 zur Senkrechten durch die Mittellinie 9 nach unten auf die Ansaugöffnung 3" des Ansaugrohrs 3 hin gerichtet ist. Die Öffnung 8 weist nach außen hin eine düsenförmige Erweiterung 10 auf. Diese Form der Öffnung sichert ein gleichmäßiges Ausströmen der Leckgase und eine optimale Auffächerung des austretenden Strahles an Leckgasen und Olnebel, so daß eine gute Vermischung mit der vom Ansaugrohr 3 angesaugten Luft erfolgt. Die Bearbeitung der Öffnungen 8 muß sehr sorgfältig erfolgen, damit keinerlei Grate und Unebenheiten entstehen. Diese könnten nämlich die Strömung sehr stark beeinflussen, so daß es zu einem ungleichmäßigen Verteilen der Leckgase käme. Der Lage der Öffnung 8 in der Rückführleitung 6 entsprechend ist das dargestellte Ansaugrohr das vorletzte der in Fig. dargestellten Ausaugrohre, von links an gerechnet.Fig. 2 shows a section through the intake box I with a view of the intake opening 3 "of an intake pipe 3. On the right side of the intake box I, one must think of the air filter as supplemented, while the mounting bracket 2 is screwed to the associated cylinder head. The intake pipe 3 opens upwards towards the viewer, while it opens into the intake port of the cylinder at the bottom left of flange 4. Above intake pipe 3, return line 6 runs clearly. An opening 8 can be seen clearly, which passes through at an angle of approximately 45 ° to the vertical the center line 9 is directed downward onto the suction opening 3 ″ of the suction pipe 3. The opening 8 has a nozzle-shaped extension 10 towards the outside. This shape of the opening ensures a uniform outflow of the leakage gases and an optimal fanning out of the emerging jet of leakage gases and oil mist, so that there is good mixing with the air sucked in by the suction pipe 3. The processing of the openings 8 must be done very carefully so that no burrs and unevenness arise. This could namely have a very strong influence on the flow, so that the leakage gases would be distributed unevenly. According to the position of the opening 8 in the return line 6, the intake pipe shown is the penultimate one of the exhaust pipes shown in FIG.

Um die Strömungsverhältnisse in dem Ansaugkasten I zu verbessern, kann die Rückführleitung 6 auch durch ein hier nicht dargestelltes kurzes, nach unten reichendes, das Rohr überdeckendes Blech gegenüber dem vorgesetzten Luftfilter abgeschirmt sein. Dadurch kann verhindert werden, daß, je nach Lage der Öffnungen 8, der vorgeschaltete Filter durch Ölnebel benetzt wird.In order to improve the flow conditions in the intake box I, the return line 6 can also be shielded from the upstream air filter by a short, downward-reaching, sheet metal plate (not shown here). This can prevent, depending on the position of the openings 8, the upstream filter from being wetted by oil mist.

Im vorliegenden Ausführungsbeispiel, wie in Fig. I dargestellt, nimmt, in Strömungsrichtung der Leckgase gesehen, der Durchmesser der jeweiligen Öffnungen 8 in der Rückführleitung 6 kontinuierlich in gleichen Schritten zu. Ist es aufgrund der konstruktiven Ausführung für die Strömungsverhältnisse vorteilhaft, können auch zwei aufeinanderfolgende Löchen den gleichen Durchmesser aufweisen.In the present exemplary embodiment, as shown in FIG. I, the diameter of the respective openings 8 in the return line 6 increases continuously in the same steps, as seen in the flow direction of the leak gases. If it is advantageous for the flow conditions due to the design, two successive holes can also have the same diameter.

Außerdem ist es denkbar, daß der gewählte Winkelversatz der Löcher auf dem Umfang der Rückführleitung 6 nicht in gleich großen Winkelschritten erfolgt. So können beispielsweise zwei aufeinanderfolgende Löcher an der gleichen Stelle des Umfangs, auf demselben Winkelgrad, liegen.In addition, it is conceivable that the selected angular misalignment of the holes on the circumference of the return line 6 does not take place in angular steps of the same size. For example, two successive holes can be located at the same point on the circumference, at the same angular degree.

Bei dem Ausführungsbeispiel nach Fig. 3 ist die Rückführleitung 6 direkt in den Zylinderkopf 10 eingearbeitet. Dabei ist die Rückführleitung 6 als geradliniger Kanal ausgebildet, der direkt beim Gießvorgang des Zylinderkopfs 2 durch einen entsprechenden Gießkern ausgespart wird oder nachträglich durch beispielsweise Bohren in den Zylinderkopf 10 eingearbeitet wird. Die Rückführleitung 6 ist oberhalb der Ansaugkanäle II angeordnet und die Öffnungen 8 münden direkt in die Gehäusewandungen der Ansaugkanäle II. Die Ausrichtung der Öffnungen 8 in die Ansaugkanäle II erfolgt analog zu den Ausführungen, wie sie in den Fig. I und 2 beschrieben sind. Die Versorgungsleitung, von der die Rückführleitung 6 mit Leckgasen und Ölnebel versorgt wird, ist bei dieser Ausführung vorteilhaft in den Zylinderkopf 10 eingearbeitet und über entsprechende Leitungen und ggf. Ventile mit dem Kurbelgehäuse des Verbrennungsmotors verbunden.In the exemplary embodiment according to FIG. 3, the return line 6 is incorporated directly into the cylinder head 10. The return line 6 is designed as a straight-line channel, which is cut out directly in the casting process of the cylinder head 2 by a corresponding casting core or is subsequently worked into the cylinder head 10 by, for example, drilling. The return line 6 is arranged above the intake ducts II and the openings 8 open directly into the housing walls of the intake ducts II. The alignment of the openings 8 in the intake ducts II is carried out analogously to the explanations as described in FIGS. I and 2. The supply line, from which the return line 6 is supplied with leakage gases and oil mist, is advantageously incorporated into the cylinder head 10 in this embodiment and connected to the crankcase of the internal combustion engine via corresponding lines and possibly valves.

Die Schnitte nach Fig. 4 und 5 zeigen die unterschiedlichen Mündungen der Öffnungen 8 in die Ansaugkanäle II des Zylinderkopfs 10, wobei bezüglich der Ausrichtung der Öffnungen 8 auf die Zeichnungsbeschreibung zu den Fig. I und 2 verwiesen wird.The sections according to FIGS. 4 and 5 show the different openings of the openings 8 into the intake ducts II of the cylinder head 10, reference being made to the description of the drawing relating to FIGS. I and 2 with regard to the orientation of the openings 8.

Die erfindungsgemäße Rückführleitung 6 kann bei allen Arten von Viertakt-Verbrennungsmotoren verwendet werden. Neben den in den Figuren dargestellten Zwei- und Vierzylinder-Motoren kommen für die Anwendung der Erfindung beispielsweise Drei-, Fünf-, Sechs- und Mehrzylindermotoren in Frage.The return line 6 according to the invention can be used in all types of four-stroke internal combustion engines. In addition to the two- and four-cylinder engines shown in the figures, three-, five-, six- and multi-cylinder engines are suitable for the application of the invention.

Fig. 6 zeigt einen Ausschnitt aus einem Zylinderkopf 3' eines Viertakt-Verbrennungsmotors mit integrierter Rückführleitung für Leckgase. Ein Ansaugrohr 2' bzw. ein Einlaßkanal für die Verbrennungsgase ist in einem Winkel von ca. 30° von der Zylinderkopfbodenplatte 9' abstehend angeordnet. Über ein Einlaßventil 10' steht das Ansaugrohr 2' mit einem nicht gezeigten Brennraum in Verbindung. Das Einlaßventil 10' ist von einem Kipphebel II' entgegen der Kraft einer Feder 12' kraftbeaufschlagbar, wobei das andere, nicht gezeigte Ende des Kipphebels II' mit der Nockenwelle bzw. dem Stößelrohr des Motors in Wirkverbindung steht. Der Kipphebel 11' mitsamt der Feder 12' ist von einer Zylinderkopfhaube 5' abgedeckt, die über eine Dichtung 13' mit dem Zylinderkopf 3' verbunden ist. Erfindungsgemäß ist der Zylinderkopf 3' als Blockzylinderkopf oder als Einzelzylinderkopf ausgebildet und im Zylinderkopf 3' eine die ganze Länge des Kopfes durchziehende Rückführleitung 4' angeordnet, d. h. die Rückführleitung 4' ist in den Zylinderkopf 3' integriert.6 shows a section of a cylinder head 3 'of a four-stroke internal combustion engine with an integrated return line for leak gases. An intake pipe 2 'or an inlet duct for the combustion gases is arranged at an angle of approximately 30 ° from the cylinder head base plate 9'. The intake pipe 2 'is connected to a combustion chamber (not shown) via an inlet valve 10'. The inlet valve 10 'can be acted upon by a rocker arm II' against the force of a spring 12 ', the other end, not shown, of the rocker arm II' being operatively connected to the camshaft or the tappet tube of the engine. The rocker arm 11 'together with the spring 12' is covered by a cylinder head cover 5 'which is connected to the cylinder head 3' via a seal 13 '. According to the invention, the cylinder head 3 'is designed as a block cylinder head or as a single cylinder head and in the cylinder head 3' there is a return line 4 'running through the entire length of the head, ie the return line 4' is integrated in the cylinder head 3 '.

Ist der Zylinderkopf 3' aus Einzelzylinderköpfen zusammengesetzt, so ist die durchgehende Rückführleitung 4' durch zwischen den Zylinderköpfen 3' angeordnete Verbindungsstücke gebildet. Als Verbindungsstücke sind z. B. Doppelsteckstücke bestens geeignet.If the cylinder head 3 'is composed of individual cylinder heads, the continuous return line 4' is formed by connecting pieces arranged between the cylinder heads 3 '. As connectors are z. B. Double plug-in pieces are ideally suited.

Die Rückführleitung 4' ist dabei in unmittelbarer Nachbarschaft der Ansaugrohre 2' angeordnet und ist entweder als Bohrung ausgebildet oder eingegossen bzw. in der Gußform ausgespart.The return line 4 'is arranged in the immediate vicinity of the intake pipes 2' and is either designed as a bore or cast in or recessed in the mold.

Damit die rückgeführten Leckgase in die jeweiligen Ansaugrohre 2' der Zylinder gelangen können, ist die Rückführleitung 4' mit den Ansaugrohren 2' über Verbindungskanäle 8' verbunden. Dabei ist jedem Ansaugrohr bzw. Einlaßkanal ein Verbindungskanal 8' zugeordnet.So that the recirculated leakage gases can get into the respective intake pipes 2 'of the cylinders, the return line 4' is connected to the intake pipes 2 'via connecting channels 8'. It is ever a connecting duct 8 'is assigned to the intake pipe or inlet duct.

Zur Vermeidung eine Olsumpfes in der Rückführleitung 4' münden vorteilhafterweise die Verbindungskanäle 8' an geodätisch tiefster Stelle in die Rückführleitung 4' .In order to avoid an oil sump in the return line 4 ', the connecting channels 8' advantageously open into the return line 4 'at the geodetically lowest point.

Die Verbindungskanäle 8' können vorteilhafterweise als Bohrungen oder als Drosselschraubstopfen 5' ausgebildet sein. Zweckmäßigerweise ist die Größe des Verbindungskanals 8' bzw. dessen Lage zuum Ansaugrohr 2' je nach Motorzylinderzahl unterschiedlich. Um eine gleichmäßige Versorgung aller Ansaugrohre 2' mit der gleichen Menge an Leckgasen sicherzustellen, ist sinnvollerweise der Strömungsquerschnitt der Verbindungskanäle 8' in Strömungsrichtung der rückgeführten Gase zunehmend ausgebildet. Wie in der Fig. 6 zu sehen, sind die Verbindungskanäle -8' von der Innenseite der Ansaugrohre 2' ausgehend in die Rückführleitung 4' eingebracht. Es entfallen dadurch zusätzliche Verschlußteile, die nötig wären, wenn die Verbindungskanäle 8' von außen eingeführt würden. Zwischen dem Verbindungskanal 8' und dem Ansaugrohr 2' ist eine Ausnehmung 14' angeordnet, die zur besseren Anbringung des Verbindungskanals 8' dient.The connecting channels 8 'can advantageously be designed as bores or as throttle screw plugs 5'. The size of the connecting duct 8 'or its position relative to the intake pipe 2' expediently differs depending on the number of engine cylinders. In order to ensure a uniform supply of all intake pipes 2 'with the same amount of leakage gases, the flow cross section of the connecting channels 8' in the flow direction of the returned gases is expediently formed. As can be seen in FIG. 6, the connecting channels -8 'are introduced into the return line 4' starting from the inside of the intake pipes 2 '. This eliminates the need for additional closure parts that would be necessary if the connecting channels 8 'were introduced from the outside. A recess 14 'is arranged between the connecting duct 8' and the intake pipe 2 'and serves for better attachment of the connecting duct 8'.

Fig. 7 zeigt eine alternative Ausführungsform, bei der die Zylinderkopfhaube 5' einteilig ausgebildet ist und die Rückführleitung 4' in die Zylinderkopfhaube integriert ist. Die Zylinderkopfhaube 5' ist unter Zwischenschaltung von Dichtungen 13' am Zylinderkopf 3' angeflanscht. Von der Rückführleitung 4' in Richtung Verbindungsnaht Zylinderkopfhaube-Zylinderkopf führt ein Verbindungskanal 8', der wie in Fig. 6 beschrieben ausgeführt ist. Der Verbindungskanal 8' kann leicht vor der Montage der Zylinderkopfhaube 5' in diesen eingebracht werden. Der Verbindungskanal 8' ist mit dem Ansaugrohr 2' über einen weiteren, im Durchmesser größeren Verbindungskanal 8' verbunden. In der Verbindungsnaht Zylinderkopfhaube-Zylinderkopf gehen die beiden Verbindungskanäle 8' ineinander über. Durch die Anordnung der Rückführleitung 4' im Bereich der steil ansteigenden Ansaugrohre 2' bzw. Einlaßkanäle, ist eine Olsumpfbildung bzw. eine Ölablagerung im Luftansauggehäuse bzw. im Ansaugrohr 2' verhindert. Selbst bei extremen Motorschräglagen ist der Ölablauf durch den 30°-Anstellwinkel des Ansaugrohrs 2' zum Zylinderkopfboden 9' (siehe Fig. 6), in Richtung Ventilsitz 15' gewährleistet.Fig. 7 shows an alternative embodiment in which the cylinder head cover 5 'is formed in one piece and the return line 4' is integrated in the cylinder head cover. The cylinder head cover 5 'is flanged to the cylinder head 3' with the interposition of seals 13 '. A connecting duct 8 'leads from the return line 4' in the direction of the seam between the cylinder head cover and the cylinder head and is designed as described in FIG. 6. The connecting channel 8 'can easily be introduced into the cylinder head cover 5' before it is installed. The connecting duct 8 'is connected to the intake pipe 2' via a further connecting duct 8 'with a larger diameter. In the connecting seam cylinder head cover cylinder head, the two connecting channels 8 'merge into one another. The arrangement of the return line 4 'in the region of the steeply rising intake pipes 2' or inlet channels prevents the formation of oil sump or an oil deposit in the air intake housing or in the intake pipe 2 '. Even with extreme engine inclinations, the oil drain is guaranteed by the 30 ° angle of attack of the intake pipe 2 'to the cylinder head base 9' (see FIG. 6), in the direction of the valve seat 15 '.

Fig. 8 zeigt eine Ansicht Fig. 8a und einen Schnitt von einem am Motor angeordneten Entlüftungsventilgehäuse 7'. Dieses Entlüftungsventilgehäuse 7' ist Bestandteil der Rückführleitung. Es ist zu erkennen, daß die Rückführleitung 4' unmittelbar über Dichtungselemente 6' z. B. einer Runddichtung an das Entlüftungsventilgehäuse 7' angeflanscht ist. Das Entlüftungsventilgehäuse 7' ist wiederum direkt mit dem Kurbelgehäuse verbunden.Fig. 8 shows a view Fig. 8a and a section of a breather valve housing 7 'arranged on the engine. This vent valve housing 7 'is part of the return line. It can be seen that the return line 4 'directly via sealing elements 6' z. B. a round seal is flanged to the vent valve housing 7 '. The vent valve housing 7 'is in turn connected directly to the crankcase.

Im Betrieb des Motors gelangen die Leckgase vom Kurbelgehäuse I' über das Entlüftungsventil im Entlüftungsventilgehäuse 7' in die Rückführleitung 4' und vo dort aus über die Verbindungskanäle 8' in die jeweiligen Ansaugrohre 2' der Zylinder. Diese erfindungsgemäße Ausführung ist kostengünstig, da kein separates Olverteilrohr und keine Verbindungsleitung zwischen Entlüftungsventil und Zylinderkopf nötig ist. Ferner ist der Platzbedarf auf ein Minimum reduziert, da die Rückführleitung 4' im vorhandenen Zylinderkopfbauraum bzw. in der Zylinderkopfhaube 5' untergebracht ist.During operation of the engine, the leakage gases pass from the crankcase I 'via the vent valve in the vent valve housing 7' into the return line 4 'and from there via the connecting channels 8' into the respective intake pipes 2 'of the cylinders. This embodiment according to the invention is inexpensive since no separate oil distribution pipe and no connecting line between the vent valve and the cylinder head is necessary. Furthermore, the space requirement is reduced to a minimum, since the return line 4 'is accommodated in the existing cylinder head space or in the cylinder head cover 5'.

Claims (20)

1. A return conduit for leakage gases from the crankcase of a four-stroke internal-combustion engine into the suction pipes of the cylinders, characterised in that the return conduit (6) is in communication with each suction pipe (3) of a cylinder through an opening (8), wherein the diameters of the openings (8) change, seen in the direction of flow of the leakage gases in the return conduit (6), and the last opening has a substantially larger diameter than the first opening and its direction of exit into the suction pipe is different from that of the first opening.
2. A return conduit for leakage gases according to claim 1, characterised in that the openings (8) are arranged in a line of spiral or nearly spiral form about the return conduit (6), while the first opening (8), seen in the direction of flow of the return conduit (6), lies on the side remote from the suction opening (3") of the suction pipe (3) and the last opening lies on the side of the return conduit (6) facing the suction opening (3") of the suction pipe (3).
3. A return conduit for leakage gases according to claim 1 or 2, characterised in that, seen in the direction of flow of the leakage gases, the diameter of the respective openings (8) in the return conduit (6) increases from the first to the last opening.
4. A return conduit for leakage gases according to any one of claims 1 to 3, characterised in that the openings (8) of the return conduit (6) have, outwards, a widening (10) of nozzle form.
5. A return conduit for leakage gases according to any one of claims 1 to 4, characterised in that the return conduit (6) is arranged as a separate pipe in the intake case (1).
6. A return conduit according to any one of claims 1 to 4, characterised in that the cylinder head (3') is formed as a block-type cylinder head and the return conduit (4') is integrated into the cylinder head (3').
7. A return conduit according to claim 6, characterised in that the cylinder head cover (5') is made in one piece and the return conduit (4') is integrated into the cylinder head cover (5').
8. A return conduit according to any one of claims 1 to 4, characterised in that the cylinder head (3') is composed of single cylinder heads, the return conduit (4') is integrated into the single cylinder heads, and a continuous return conduit (4') is formed by connection pieces arranged between the single cylinder heads.
9. A return conduit according to claim 8, characterised in that the return conduit (4') is integrated into the single cylinder head covers.
10. A return conduit according to any one of claims 6 to 9, characterised in that the return conduit (4') is formed as a bore.
11. A return conduit according to any one of claims 6 to 9, characterised in that the return conduit (4') is cast into position.
12. A return conduit according to any one of claims 6 to 11, characterised in that the return conduit (4') extends through the whole length of the cylinder head (3') and is arranged in the immediate vicinity of the suction pipes (2').
13. A return conduit according to any one of claims 6 to 12, characterised in that the return conduit (4') is flanged directly through sealing elements (6') to a venting valve housing (7')..
14. A return conduit according to any one of claims 6 to 13, characterised in that the return conduit (4') is connected with the suction pipes (2') through connection passages (8').
15. A return conduit according to claim 14, characterised in that the connection passages (8') open into the return conduit (4') at the geodetically lowest point.
16. A return conduit according to claim 14 or 15, characterised in that the connection passages (8') are made as bores.
17. A return conduit according to any one of claims 14 to 16, characterised in that the connection passages (8') are formed as a threaded throttle stopper.
18. A return conduit according to any one of section of the connection passages (8') increases in the direction of flow of the returned gases.
19. A return conduit according to any one of claims 6 to 18, characterised in that the suction pipes (2') protrude at an angle of about 30° from the cylinder head base plate (9').
20. A return conduit according to any one of claims 1 to 19, characterised in that a supply conduit for the return conduit (6) is machined into the cylinder head (10).
EP87109025A 1986-07-01 1987-06-23 Return line for leak gas from a crank case Expired - Lifetime EP0251159B1 (en)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
DE3622024 1986-07-01
DE19863622024 DE3622024A1 (en) 1986-07-01 1986-07-01 Return line for leakage gases from the crankcase
DE19873704567 DE3704567A1 (en) 1987-02-13 1987-02-13 Return line for leakage gases from the crankcase
DE3704567 1987-02-13

Publications (3)

Publication Number Publication Date
EP0251159A2 EP0251159A2 (en) 1988-01-07
EP0251159A3 EP0251159A3 (en) 1989-02-01
EP0251159B1 true EP0251159B1 (en) 1990-10-24

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ID=25845142

Family Applications (1)

Application Number Title Priority Date Filing Date
EP87109025A Expired - Lifetime EP0251159B1 (en) 1986-07-01 1987-06-23 Return line for leak gas from a crank case

Country Status (2)

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EP (1) EP0251159B1 (en)
DE (1) DE3765705D1 (en)

Cited By (4)

* Cited by examiner, † Cited by third party
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DE4038509A1 (en) * 1990-12-03 1992-06-11 Mann & Hummel Filter INTAKE DISTRIBUTOR FOR AN INTERNAL COMBUSTION ENGINE
DE10045636A1 (en) * 2000-09-15 2002-03-28 Audi Ag Secondary gas directing device, has channel integrated with wall section of collecting area, the channel communicating at one end with connecting piece and with inlet openings at the other
DE19546545B4 (en) * 1995-12-13 2006-01-12 Mahle Filtersysteme Gmbh intake manifold
DE102008021055A1 (en) 2008-04-26 2009-10-29 Ford Global Technologies, LLC, Dearborn Combustion engine comprises valve hood, steering housing and positive crankcase ventilation system assigned on cylinder head, and component of positive crankcase ventilation system is integrated in steering housing

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DE4111772A1 (en) * 1991-04-11 1992-10-15 Kloeckner Humboldt Deutz Ag INTAKE SYSTEM FOR A SELF-IGNITION COMBUSTION ENGINE
DE4221913C1 (en) * 1992-07-03 1994-01-27 Freudenberg Carl Fa Intake manifold for an internal combustion engine with a cylinder head
US5307784A (en) * 1993-04-05 1994-05-03 Ford Motor Company Induction system for internal combustion engine
DE4406986B4 (en) * 1994-03-03 2005-05-12 Deutz Ag Reciprocating internal combustion engine
DE29901854U1 (en) * 1999-02-03 2000-06-29 Fink, Gerhard, 35080 Bad Endbach Internal combustion engine, compressor or pump, with the channels controlling the rotary valves rotating around the axes of the cylinders and directly driven by external teeth
SE520863C2 (en) 2000-05-05 2003-09-09 Volvo Personvagnar Ab Method and apparatus for venting gases in an internal combustion engine
US7246610B2 (en) * 2003-10-07 2007-07-24 S & S Cycle, Inc. Cylinder head
DE102011014541B4 (en) 2011-03-19 2019-01-17 Audi Ag Air supply element for an internal combustion engine and method for manufacturing an air supply element

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DE318639C (en) *
US1478094A (en) * 1922-12-30 1923-12-18 Harry D Barrett Oiling system
US2057123A (en) * 1935-11-09 1936-10-13 William B Ullrich Means for lubricating and cooling engine valves
US2681051A (en) * 1952-07-03 1954-06-15 Lawton H Robinson Vapor top oiler
US3156226A (en) * 1963-05-23 1964-11-10 William J Linn Air intake fitting for internal combustion engine
DE2036045A1 (en) * 1970-07-21 1972-03-09 Daimler-Benz Ag, 7000 Stuttgart Multi-cylinder injection internal combustion engine

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE4038509A1 (en) * 1990-12-03 1992-06-11 Mann & Hummel Filter INTAKE DISTRIBUTOR FOR AN INTERNAL COMBUSTION ENGINE
DE19546545B4 (en) * 1995-12-13 2006-01-12 Mahle Filtersysteme Gmbh intake manifold
DE10045636A1 (en) * 2000-09-15 2002-03-28 Audi Ag Secondary gas directing device, has channel integrated with wall section of collecting area, the channel communicating at one end with connecting piece and with inlet openings at the other
DE10045636B4 (en) * 2000-09-15 2012-04-12 Audi Ag Apparatus for carrying a secondary gas
DE102008021055A1 (en) 2008-04-26 2009-10-29 Ford Global Technologies, LLC, Dearborn Combustion engine comprises valve hood, steering housing and positive crankcase ventilation system assigned on cylinder head, and component of positive crankcase ventilation system is integrated in steering housing
DE102008021055B4 (en) * 2008-04-26 2015-10-22 Ford Global Technologies, Llc Internal combustion engine with a protected PCV system

Also Published As

Publication number Publication date
EP0251159A2 (en) 1988-01-07
DE3765705D1 (en) 1990-11-29
EP0251159A3 (en) 1989-02-01

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