GB2321672A

GB2321672A - Venting device with integrated oil separator for a crankcase of an internal combustion engine

Info

Publication number: GB2321672A
Application number: GB9801731A
Authority: GB
Inventors: Roland Clauss; Georg Leipner; Willy Treyz
Original assignee: Daimler Benz AG
Current assignee: Daimler Benz AG
Priority date: 1997-02-01
Filing date: 1998-01-27
Publication date: 1998-08-05
Anticipated expiration: 2018-01-27
Also published as: ITRM980060A0; IT1298883B1; FR2759115A1; GB2321672B; GB9801731D0; ITRM980060A1; DE19703770C1; FR2759115B1

Abstract

A vent device with integrated oil separator for a crankcase of an i.c. engine with cylinder head 11 and cylinder head cover 5 having a housing consisting of a lower part and an upper lid part 8, with an inlet (18, figure 2) for vent gases from the crankcase leading to a crude gas space 16 in the housing which is separated from a clean gas space 17 by a partition, the crude gas space 16 and the clean gas space 17 having an outlet orifice 20 and inlet orifice 21 respectively adjacent each other, causing 180 degree change in direction of the air steam resulting in separation of the oil; the orifices 20,21 being positioned above a port leading back to the crankcase, through which the oil returns. Preferably the outlet orifice 20 is at an end of a narrow duct 19, which is surrounded by clean air space 17, and accelerates the oil droplets in the air stream.

Description

1 Vent device with integrated oil separator for a crankcase of an internal

combustion engine 2321672 The invention relates to a vent device with integrated oil separator for a crankcase of an internal combustion engine, especially but not exclusively, with cylinder rows arranged in a V-shaped manner, having a housing consisting of an upper part and a lower part, with an inlet for vent gases rising out of the crankcase and with an outlet for the vent gases which are freed of oil and which pass via a connecting conduit to the suction pipe of the internal combustion engine.

A vent device of this type with integrated oil separator is known from DE 37 13 210 C2. The vent device and the oil separator are an integral part of a housing provided with baffles and located in the V-space of the cylinder rows of the internal combustion engine which are arranged in a Vshaped manner. The housing consisting of an upper part and a lower part is pot-shaped and consists of plastic. The baffles are formed by partially overlapping webs of the upper part and lower part. The inlet of the vent gases takes place directly from the crankcase into the pot- shaped housing through which the vent gases flow.

The present invention is based on a vent device of the generic type with integrated oil separator, to provide special measures which allow uncomplicated manufacture and assembly, require only a small amount of space on the internal combustion engine and nevertheless ensure crankcase venting which functions efficiently.

According to the present invention there is provided a vent device with integrated oil separator in a crankcase of an internal combustion engine with cylinder head and cylinder head cover, having a housing consisting of a lower part and of a lidlike upper part., with an inlet for vent gases rising out of the crankcase and with a gas outlet for the vent gases which are freed of oil and which pass via a connecting conduit to the inlet passage of the internal combustion engine, wherein the lower part of the housing carrying vent gases is a cover part of the cylinder head cover, between which cover part and the lid-like upper part a partition is provided for separating a crude-gas space from a clean-gas space, of which the crude-gas space has an outlet orifice facing the cylinder head and the clean-gas space has an inlet orifice adjacent to the outlet 2 orifice, and an inlet port of an oil return leading to the crankcase is arranged below the two orifices, the said inlet orifice allowing the reversal of flow of the vent gases.

Beneficial developments of the invention are also specified in the subclaims.

Since the lower part or bottom of the housing carrying vent gases is a structural part of the cylinder head cover, a considerable simplification of the vent housing is achieved in production terms. Moreover, the lower part, which is formed by the cylinder head cover itself, ensures a weight saving. A further advantage is a space-saving construction space, so that no appreciable restriction in the design of conventional mounted parts in the region of the longitudinal side of the internal combustion engine has to be accepted.

The arrangement of the partition in the housing likewise results in a simple way in spatial separation between the crude-gas space and the clean-gas space.

With a view to a further simplification of manufacture, the outlet orifice on the crude-gas side and the inlet orifice on the clean-gas side as well as an inlet port on the cylinder-head side, the said inlet port overlapping the two orifices, can lie in a separating plane formed by the cylinder head cover and the cylinder head.

The event gases are accelerated due to the special design of the narrow duct outlet on the crude-gas side.

An embodiment of the invention is illustrated in the drawing and is explained in more detail below with reference to the drawing, in which:

Figure 1 shows a top view of a cylinder head cover with a closed housing carrying the vent gases, Figure 2 shows, on an enlarged scale, a top view of the housing partially covered by an upper part, Figure 3 shows an enlarged illustration, in cross-section, of an oil separator integrated in the housing, and Figure 4 shows the oil separator from the underside of the cylinder head cover.

A vent device 1 with integrated oil separator 2 for a multi-cylinder internal combustion engine 3 having cylinder rows 4 arranged in a Vshaped manner consists of a slender elongate housing 6 which is arranged on the cylinder head cover 3 and which is composed of a lower part 7 and of a lid-like upper part 8 (Figure 3). The lower part 7 of this housing 6 is the cover part of the cylinder head cover 5 (Figure 2) and forms one limiting wall 9 extending over half of one cylinder row 4. The opposite limiting wall 10 runs parallel to the limiting wall 9 and is integrally formed on the cylinder head cover 5 in a lower region 5a which faces the cylinder head 11 and starting from which the limiting wall 10 runs laterally upwards and, as seen in cross-section, has, together with the limiting wall 9, a V-shaped form. The end faces 12,13 of the housing 6 are likewise integrally formed on the cylinder head cover 5.

The cylinder head cover 5 and the lower part 7 of the housing 6 thus form a one-piece structural unit.

The housing 6 is provided with a partition 14 which separates a crudegas space 16 from a clean-gas space 17. For the sake of simpler machining, the partition 14 is integrally formed on the lid-like upper part 6, on the one hand, and on the cylinder head cover 5, on the other hand (Figure 3). However, it may also be integrally formed on the cylinder head cover 5 only and, starting from this, extend continuously as far as the lid- like upper part 8.

The oil-enriched vent gases driven upwards out of the crankcase are sucked in out of a space in the cylinder head 11, the said space being free of splash oil, and flow into the crude-gas space 16 via the inlet 18 located approximately in the longitudinal centre of the cylinder head cover 5. The vent gases are carried through the crude-gas space as far as one end face 13 of the cylinder head cover 5 and, after running in an arc, are guided into a narrow duct 19 running in the direction of the cylinder head 11 and having a small cross-section. The oil droplets contained in the vent gases are greatly accelerated at the same time.

The outlet orifice 20 of this duct 19 lies in a separating plane A formed by the cylinder head cover 5 and the cylinder head 11, as does an adjacent inlet orifice 21 connected to the clean-gas space 17 and having a relatively large cross-section (Figure 3).

The inlet orifice 21 surrounds the outlet orifice 20 in a U-shaped manner (Figure 4). The two orifices are located in a projecting part 22 on the end face of the cylinder head cover 5. Below these orifices, an inlet port 23 overlapping these two 4 orifices is provided in the cylinder head 11. A reversal of flow of the vent gases freed of oil takes place in the region of these orifices. The oil droplets are not deflected due to their inertia, but pass into a cavity 24 cast on the cylinder head 11, into an oil return in the crankcase, the said oil return not being illustrated in any more detail.

After the reversal of flow of the vent gases, these pass via the inlet orifice 21 into the clean-gas space 17 which extends approximately as far as half the entire length of the housing 6 (Figure 1) and which, at its end located opposite the inlet orifice 2 1, has a lateral gas outlet 25 in the lid-like upper part 8, the said gas outlet being connected (not illustrated in any more detail) to the inlet passage of the internal combustion engine via a connecting conduit 26..

The upper part 8 designed as a lid is sealed off on the housing 6 by means of a silicone-filled tongue-and-groove connection 27 which is screwed to the cylinder head cover 5 and which also extends over the entire length of the partition halves (Figures 1, 3, 4).

Claims

1. A vent device with integrated oil separator in a crankcase of an internal combustion engine with cylinder head and cylinder head cover, having a housing consisting of a lower part and of a lid-like upper part, with an inlet for vent gases rising out of the crankcase and with a gas outlet for the vent gases which are freed of oil and which pass via a connecting conduit to the inlet passage of the internal combustion engine, wherein the lower part of the housing carrying vent gases is a cover part of the cylinder head cover, between which cover part and the lid-like upper part a partition is provided for separating a crude-gas space from a clean-gas space, of which the crude-gas space has an outlet orifice facing the cylinder head and the clean gas space has an inlet orifice adjacent to the outlet orifice, and an inlet port of an oil return leading to the crankcase is arranged below the two orifices, the said inlet orifice allowing the reversal of flow of the vent gases.

2. A vent device according to Claim 1, wherein the outlet orifice on the crude-gas side and the inlet orifice on the clean-gas side as well as the inlet port on the cylinder-head side, overlapping the two orifices, lie in a separating plane running through the cylinder head cover and the cylinder head.

3. A vent device according to Claim 1 or 2, wherein the crude-gas space merges into a downwardly directed duct extending as far as the outlet orifice and having a small cross-section, the inlet orifice of the duct on the clean- gas side having a relatively large cross-section.

4. A vent device according to Claim 2 or 3, wherein the duct on the clean gas side surrounds the duct on the crude-gas side in a U-shaped manner in the region of the separating plane.

5. A vent device according to Claim 4, wherein the walls limiting in each case the duct on the clean-gas side and that on the crude-gas side are integrally formed externally on the end face of the cylinder head cover.

6 A vent device according to Claim 1, wherein the upper part comprises a lid and is sealed off by means of a silicone-filled tongue-and-groove connection secured to the cylinder head cover.

6

7. A vent device according to Claim 1, wherein the housing containing vent gases extends approximately over half the length of the cylinder row of the internal combustion engine, the inlet of the vent gases being located approximately in the longitudinal centre of the cylinder row.

8. A vent device with integrated oil separator in a crankcase of an internal combustion engine with cylinder head and cylinder head cover, substantially as described herein with reference to, and as illustrated in, the accompanying drawings.