EP0978639B1 - Cylinder head cover - Google Patents

Description

The invention relates to a cylinder head cover for an internal combustion engine, in particular a gasoline or diesel engine, especially for a motor vehicle, with a Vent valve, a first side, a second opposite the first side Side and a blanket, the vent valve comprising the following Base frame and a lid, which together form a valve housing, wherein a membrane (24) is arranged in the valve housing and rests on a seat supports and the valve housing in a first chamber, which with a Air intake duct of the internal combustion engine is connected, and a second chamber, which via a flow channel with an interior of a to be vented Crankcase is connected, according to the preamble of claim 1.

A generic cylinder head cover is for example from DE 36 15 397 C2 known. Here, an exhaust air duct connects the room to be vented Crankcase with a chamber of the ventilation device. The exhaust duct is as an opening in a common wall of the vent valve and Cylinder head cover executed. In addition, a is in the venting device mechanical liquid separator provided.

Document EP 0 730 086 A1 relates to a cyclone separator for crankcase ventilation an internal combustion engine with a vent valve, the Cyclone separator as a horizontal spiral separation channel with von radially inward the same or decreasing cross sections and with in Ratio to the largest outer diameter of the cyclone part many times over lower channel height is formed. Both the cyclone separator and one Suction openings are arranged immediately adjacent to the vent valve.

Document DE 33 26 881 A1 relates to a crankcase ventilation for a Internal combustion engine, wherein the ventilation valve and the cylinder head cover completely or essentially form a structural unit. The vent valve is an oil separator upstream, which consists of a substantially the length of the Cylinder head cover extending air duct, which is approximately in to the valve chamber half the hood height is tightly closed by a cover plate. The entrance opening the exhaust gases are located away from the vent valve.

Document EP 0 744 535 A1 relates to an internal combustion engine with a Oil separation chamber in the cylinder head cover, the oil separation chamber Oil channels that run like a labyrinth and are closed by an oil separator plate has a discharge of oil separated from oil mist via the Allow cylinder crankcase in an oil reservoir. The oil channels are in divided several sectors, so that through the openings in the space above the Oil separator plate entering oil and thus the oil selectively drains and thus the oil collection container can be fed.

Document US 4,721,090 relates to a crankcase ventilation for a Internal combustion engine, with a breathing chamber between the cylinder head cover and a baffle plate attached to the cylinder head cover is provided. The Breathing chamber stands with the interior of the cylinder head and one Air intake unit in connection. The respiratory chamber is divided into three sections, the are connected to each other via channels. In the breathing chamber is in blow-by gases contained oil mist separated.

Document EP 0 591 737 A1 relates to a system for venting oil vapor from a Crankcase of an internal combustion engine. Here are vertical in the cylinder head Bores are provided for removing oil condensed in the cylinder head. This vertical holes are partly parallel to feed-through holes for Fastening bolt arranged and at least one vertical bore is with a Feedthrough holes connected. Out of the cylinder head is an immediate one Connection to a ventilation opening provided on the cylinder head cover.

Document US 4 993 375 relates to a cylinder head cover, which on one long side a U-shaped blow-by gas channel with an oil separation main channel and on one opposite long side another U-shaped air duct with a Has oil separation subchannel. Ambient air is injected into the air duct Crankcase introduced to displace blow-by gases from the crankcase and to be discharged via the blow-by gas channel.

Document DE 197 32 367 A1 relates to a crankcase ventilation valve for a Internal combustion engine with a valve housing, one with the interior of the Crankcase connected gas inflow duct, one with an air intake duct Internal combustion engine connected gas discharge channel and a membrane, which the Splits valve housing into an inner chamber and an outer chamber on the crankcase side and has a breather valve plate, the membrane with the breather valve plate Depending on the pressure difference between the two chambers, the gas discharge channel is optional opens or closes. The outer chamber of the valve housing with the Gas inflow channel connected and further a ventilation channel on the crankcase side formed, which the inner crankcase chamber of the valve housing with connects an ambient pressure.

The invention has for its object a cylinder head cover of the above Art to provide, with improved oil separation from the Escaping crankcase gases is achieved in a simple manner.

This object is achieved by a cylinder head cover of the above. Kind with the features characterized in claim 1 solved. Advantageous embodiments of the Invention are specified in the dependent claims.

For this purpose, it is provided according to the invention that the flow channel includes: a first flow space, which on the first side of the cylinder head cover and in arranged gas-conducting connection with the second chamber, a second Flow space, which is on the second side of the cylinder head cover and in gas-conducting Connection is formed with the interior of the crankcase to be vented, and an overflow channel, which is on the ceiling of the cylinder head cover on the crankcase side is formed and the second flow space with the first flow space combines.

This has the advantage that one is already in front of the actual ventilation device additional calming room for oil separation from escaping Crankcase gases are available, making the ventilation device easier and less space can be trained to be consumable. A direct splash of oil into the Venting device, for example through below the cylinder head cover moving valves is effectively avoided. Furthermore, the additional Volume reduced flow velocities, which further calm down contribute and provide a damping effect with respect to air blasts. The The damping effect also reduces the entrainment of oil droplets venting the interior of the crankcase into the venting device, causing there less oil has to be separated from the escaping crankcase gases. Furthermore is the removal of crankcase gases by an appropriate arrangement of the second flow space adapted to corresponding fluidic Conditions in the crankcase and removed from places in the crankcase where splashes a lot of oil, flexibly and optimizes regardless of where it is installed Venting device can be designed.

For further calming of flowing crankcase gases and for prevention the entrainment of oil through the overflow channel is advantageously such is designed so that it is a particular in the operating position of the internal combustion engine has an arcuate increase against a direction of gravity.

To achieve low flow velocities in the second flow space this is designed, for example, such that it extends over an entire longitudinal side of the Cylinder head cover extends.

The second flow space expediently has at least on the crankcase side a connecting wall with at least one through hole as a connection to the interior of the crankcase.

To avoid oil splashes into the second flow space, the second one points Flow space on the crankcase side at least one closed wall, which adjoins the connecting wall and extends beyond it into the Interior of the crankcase extends into it.

In a particularly preferred embodiment, the second flow space is at one opposite the venting device and the first flow chamber one side of the cylinder head cover closest to the ventilation device, the overflow channel across a ceiling of the cylinder head cover the entire width of one side with the second flow space to the corresponding other side extends with the first flow space.

Fig. 1 eine bevorzugte Ausführungsform einer erfindungsgemäßen Zylinderkopfhaube in Unteransicht und

Fig. 2 in einer Schnittansicht entlang Linie A-A von Fig. 1.

Further features, advantages and advantageous embodiments of the invention result from the dependent claims and from the following description of the invention with reference to the accompanying drawings. These show in

Fig. 1 shows a preferred embodiment of a cylinder head cover according to the invention in bottom view and

FIG. 2 in a sectional view along line AA of FIG. 1.

The preferred embodiment shown in FIGS. 1 and 2 Cylinder head cover 10 according to the invention comprises a ventilation device 12, a first side 14, a second side 16 opposite the first side 14 and one Blanket 18. Adjacent to and near first side 14 is vent 12 arranged, which comprises the following, a base frame 20 and a cover 22, which together form a valve housing 20, 22. In the valve housing 20, 22 is a membrane 24 is arranged, which is supported on a seat 26 and the Valve housing 20, 24 in two chambers 28 and 30, namely a lower chamber 28 and an upper chamber 30. The lower chamber 28 is arranged on the crankcase side and the upper chamber 30 is opposite on a side facing away from the crankcase Side of the valve housing 20, 22 formed.

The seat 26 of the membrane 24 and the base frame 20 of the valve housing 20, 22 are formed integrally with the cylinder head cover 10. It is also a gas outflow channel 32 with a connector 34 for connection to an air intake duct, not shown the internal combustion engine provided. This gas discharge channel 32 cannot in one Alternative embodiment shown can also be formed on the cover 22. On this is the upper chamber 30 with the air intake duct Internal combustion engine connected. So 30 get into the upper chamber Crankcase gases are returned to the combustion process of the internal combustion engine and do not escape into the environment. On the membrane 24 is a vent valve plate 36 is arranged in such a way that when the membrane 24 moves back and forth either opens or closes the gas discharge channel 32.

The venting device 12 or its upper chamber 30 is via a Flow channel connected to an interior of the crankcase to be vented, the flow channel according to the invention from the following components composed. A first flow space 38, an overflow channel 40 and one second flow space 42. The first flow space 38 is on the first side 14 in gas-conducting connection with the ventilation device 12 and from the device to be vented Interior of the crankcase trained completed. The second flow space 42 is a full length of the second side 16 with a first wall 44 and one second wall 46 is formed. The first wall 44 is provided with openings 48, which is a gas-conducting connection between the second flow space 42 and the provide the interior of the crankcase to be vented. Through this Openings 48 enter crankcase gases from the interior of the crankcase the second flow space 42.

The overflow channel 40 is on the ceiling 18 of the cylinder head cover 10 formed on the crankcase side and connects the second flow chamber 42 with the first flow space 38. By a correspondingly broad design of this Overflow channel 40 there are low flow speeds, so that a entrainment of oil droplets as the crankcase gases pass through the second Flow space 42 via the overflow channel 40 into the first flow space 38 is avoided. This may be supported by the fact that the overflow channel is arcuate is designed so that the arch shape is an incline to be overcome for possibly entrained oil droplets caused by the low flow rate cannot be overcome by the oil droplets in the overflow channel 40. This then fall back into the second under the influence of gravity Flow space 42, where it enters the interior of the crankcase, for example the openings 48 fall back.

In the illustrated embodiment, the second flow space 42 is the Venting device 12 arranged opposite the second side 16, so that the Openings 48 least of those working through under the cylinder head cover 10, Valves, not shown, are sprayed with oil. As can be seen in particular from FIG. 2 results, the wall 46 of the second flow space 42 is above the wall 44 towards the crankcase to form an additional splash guard extended.

As a result, there is an oil portion in the outflow via the ventilation device 12 Crankcase gases significantly reduced, with the solution according to the invention any design of the crankcase and the cylinder head cover a suction the crankcase gases always and regardless of the installation location of the Venting device 12 with respect to a minimal penetration of oil into the Venting device 12 optimal location by appropriate arrangement of the second Flow space 42 can take place.

Claims (6)

1. Cylinder-head cover for an internal combustion engine, in particular a spark-ignition or diesel engine, in particular for a motor vehicle, having a venting valve (12), a first side (14), a second side (16) which lies opposite the first side (14), and a ceiling (18), the venting valve (12) comprising the following: a basic frame (20) and a cover (22) which together form a valve housing (20, 22), a diaphragm (24) being arranged in the valve housing (20, 22), which diaphragm (24) is supported on a seat (26) and subdivides the valve housing (20, 22) into a first chamber (28) which is connected to an air-intake duct of the internal combustion engine and a second chamber (30) which is connected, via a flow duct, to an interior space of a crankcase to be vented, characterized in that the flow duct comprises the following: a first flow space (38) which is arranged on the first longitudinal side (14), adjacent to the venting valve (12) and extending along the bank of cylinders, of the cylinder-head cover (10) and has a gas-conducting connection to the second chamber (30); a second flow space (42) which is formed on the second longitudinal side (16), lying opposite the first longitudinal side (14), of the cylinder-head cover (10) and has a gas-conducting connection to the interior space of the crankcase to be vented; and a crossflow duct (40) which is formed on the crankcase side on the ceiling (18) of the cylinder-head cover (10) and connects the second flow space (42) to the first flow space (38).
2. Cylinder-head cover according to Claim 1, characterized in that the crossflow duct (40) is formed in such a way that, in the operational position of the internal combustion engine, it has an in particular arcuate elevation counter to a direction of the force of gravity.
3. Cylinder-head cover according to one of the preceding claims, characterized in that the second flow space (42) is formed so as to extend over one entire longitudinal side (16) of the cylinder-head cover (10).
4. Cylinder-head cover according to one of the preceding claims, characterized in that, on the crankcase side, the second flow space (42) has at least one connecting wall (44) with at least one opening (48) as a connection to the interior space of the crankcase to be vented.
5. Cylinder-head cover according to Claim 4, characterized in that, on the crankcase side, the second flow space (42) has at least one closed wall (46) which adjoins the connecting wall (44) and extends beyond the latter into the interior space of the crankcase.
6. Cylinder-head cover according to one of the preceding claims, characterized in that the crossflow duct (40) extends transversely over the ceiling (18) of the cylinder-head cover (10) across the entire width of the latter from the one side (16) having the second flow space (42) to the corresponding other side (14) having the first flow space (38).

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