WO2007131670A2

WO2007131670A2 - Cyclone with a deflecting element as a separator in the crankcase ventilation system of an internal combustion engine

Info

Publication number: WO2007131670A2
Application number: PCT/EP2007/004073
Authority: WO
Inventors: Sieghard Pietschner; Lars Deters
Original assignee: Hengst Gmbh & Co. Kg
Priority date: 2006-05-11
Filing date: 2007-05-08
Publication date: 2007-11-22
Also published as: EP2018467A2; DE202006007625U1; WO2007131670A3; DE502007004792D1; ATE478241T1; EP2018467B1

Abstract

The invention relates to an oil separator for removing oil from crankcase ventilation gases of an internal combustion engine, wherein the oil separator comprises at least one cyclone (1) which has a gas inlet (2), wherein the cyclone (1) is assigned a cover (3) in which is arranged a gas outlet (4, 6), and wherein the cyclone (1) is assigned a deflecting element (9, 19, 24, 29, 32, 33) in its interior (7). The oil separator according to the invention is characterized in that the deflecting element (9, 19, 24, 29, 32, 33) is formed, as viewed in the peripheral direction of the cyclone (1), with varying longitudinal extents with respect to the cover (3).

Description

Description :

Cyclone with rejection element as separator in the crankcase ventilation system of an internal combustion engine

The invention relates to an oil separator for de-oiling crankcase ventilation gases of an internal combustion engine, wherein the oil separator comprises at least one cyclone having a gas inlet, wherein the cyclone is associated with a lid in which a gas outlet is arranged, and wherein the cyclone in its interior Is assigned rejection element.

EP 1 095 209 B1 relates to an oil separator for deoiling crankcase ventilation gases of an internal combustion engine, wherein the oil separator comprises at least one cyclone having a gas inlet connected to the crankcase of the internal combustion engine, a gas outlet connected to the air intake tract of the internal combustion engine and one with the oil sump Internal combustion engine has associated oil outlet. The gas outlet protrudes as a dip tube through a top closing the cyclone in the cyclone interior. Above the gas outlet, a gas line section is provided above the cover with a jumped to at least twice the enlarged cross-section. From the gas line section, accumulating oil can be returned to the oil outlet or to the oil sump. The dip tube ends just above the lid. From the top of the lid, starting from the gas a Ölableitkanal separated from the dip tube to the oil outlet or led to the oil sump.

DE 100 65 328 A1 discloses a gas / liquid separator having a generally cylindrical container defining inside a cyclone chamber and having a gas inlet disposed on an inner peripheral wall of the cyclone chamber for introducing a gas into the cyclone chamber in a circumferential direction of the cyclone chamber for separating a liquid component from the gas through a centrifugal separation action, with a gas passageway having a gas outlet connected to the cyclone chamber via the gas outlet, the gas outlet being disposed separately from the gas inlet in the axial direction of the container , and a baffle disposed in the cyclone chamber and generally dividing a space between the gas outlet and the gas inlet to form a gas flow flowing from the gas inlet to the gas outlet along the inner peripheral wall, the gas passage conduit from the baffle at the gas inlet projected side.

DE 43 44 507 Al deals with a cyclone for the separation of oil from oil-containing aerosols. In the interior of the cyclone extends an exhaust pipe. The exhaust port is flared from its lower inlet end to its upper outlet end. The exhaust pipe is enclosed near its inlet end by a hollow cone-shaped Abweisring whose larger diameter faces the inlet end.

Cyclones as oil separators are known in the crankcase ventilation area. Depending on the application (eg Ottooder diesel engine, type of ventilation system) depending on the design, the cyclones reduce the requirement to reduce the oil content in the blow-by gas (crankcase ventilation gas). For fine oil cyclones, the geometry is designed and designed in such a way that effectively the finest oil mist droplets (fine oil: x _T ro _Pfe n <10 μm) are deposited. For this purpose, the cyclone or the cyclone size with respect to the differential pressure behavior is adapted to the operating conditions of the engine, in particular its blow-by map, adjusted so that sufficiently wide cyclone differential pressures prevail over wide engine operating ranges for effective fine oil separation.

At high engine oil discharge rates, e.g. in the form of coarse oil (coarse oil: Xτropfen> 10 microns, visible oil components in splash or Kriechölform), it may be necessary, in addition to the fine oil separator (fine oil cyclone or other Feinölabscheidertypen, eg textile separator) coarse oil to use. These are usually integrated on the crankcase side of the fine oil separator in the venting systems. Possibly. In the case of low fine oil ejection quantities, a fine oil separator can be dispensed with, so that the oil separation (protection against oil entrainment in the intake tract) is only guaranteed by the coarse oil separator. In order not to detune the pressure balance of the engine or the internal combustion engine, these coarse oil separators are adapted to their specific task by the geometry. As a rule, the differential pressures are below the values for the fine oil separators.

As coarse oil separators also offer cyclones. Conventional simple-dip-tube cyclones, however, show weaknesses in the deposition, especially when coarse oil in the form of entrained drops and splashes occurs. Drops that hit the dip tube run down and are partially covered by the dive lower edge of the tube inside the immersion tube transported upwards to the clean side. In some cases, smaller coarse oil droplets (^ drops> 10 μm <50 μm) are not deposited in the required low differential pressure design of coarse oil cyclones, but are transported undesirably directly to the clean side.

In order to avoid the entrainment of oil components of the Tauchrohraußenwand inside, so-called baffles or deflector rings are used around the dip tube, such. B. in DE 100 65 328 Al and in DE 43 44 507 Al executed. However, these designs do not show the desired effect for the requirements in the crankcase ventilation area.

Based on the requirements in the crankcase ventilation area, the known measures for avoiding the oil pressure rupture by the cyclone are not a suitable solution. The time of oil leakage is delayed at most. Coarse oil is not safely separated over longer periods of time (normal driving). Oil components that have already been separated are squirted by the vortex flow. These drops are then transported by the flow on to the clean side. At 45 ° pitch of the cyclone, conventional baffles or deflector rings do not perform the desired function.

Entrained oil components can basically be traced back to the cyclone oil outlet by the so-called pure-side oil drain holes from the immersion pipe clean side, as comprehensively shown in EP 1 095 209, which has proven itself in practice. However, this existing solution must be adapted to the relatively high coarse oil volumes accordingly and means a correspondingly increased technical standard when implemented in series Effort and space requirements and thus additional costs.

The invention has for its object to improve an oil separator of the type mentioned in that its deposition efficiency is improved, at the same time a simple and inexpensive oil separator is to be provided.

The solution of this object is achieved according to the invention by an oil separator of the type mentioned, which is characterized in that the rejection element seen in the circumferential direction of the cyclone with respect to the lid is designed with varying longitudinal extents.

In the case of the oil separator according to the invention, a 100% oil separation efficiency, for example of creeping oil and spray oil, is achieved with the special geometric configuration of the rejection element. The oil separator can be used both as a coarse oil separator and as a fine oil separator.

In this case, the gas outlet in the cover can be designed as a dip tube, which protrudes into the interior of the cyclone. Of course, the gas outlet can also be designed as a simple line, which is introduced only in the lid and preferably flush with the bottom of the lid, so it does not protrude into the interior of the cyclone.

Favorable in the context of the invention is when the rejection element has a free edge, which is designed with respect to the cover in the circumferential direction of the cyclone with varying lengths or heights. It is expedient for the purposes of the invention if the rejection element is arranged to run concentrically around the center axis in the interior of the cyclone, so that the deflecting element is arranged in a quasi-cylindrical manner in a cross section through the cyclone. Conceivable, however, is of course any geometric configuration of the rejection element, for example, a quadrangular in cross-section design or the like.

In a first advantageous embodiment, the gas inlet is arranged in the upper region of the cyclone, ie near the lid.

In this embodiment, the rejection element is advantageously arranged on or connected to the cover and extends with its free edge in the direction of a cone-shaped region of the cyclone opposite the cover, at the apex of which the oil outlet is preferably arranged.

Favorable in the context of the invention is when the rejection element has a course at its free edge, which resembles quasi an obliquely cut cylinder. In this case, the rejection element with respect to the lid advantageously has a minimum height (hs _m i _n ) and a maximum height (hS _ma x), which are arranged diametrically opposite relative to a central axis of the cyclone. In this embodiment, the deposited on the Abweiselement drops run on its outer wall to the free edge. Drops adhering to the free edge are conveyed by the vortex flow to the deepest point of the rejection element (hS _max ), so that the oil drops drip at this point in a targeted and continuous manner. The maximum height (hs _ma x) / thus the lowest point of the rejection element, is in particular in their position to the gas inlet in Inside of the cyclone depending on the application determinable or variable. The targeted dripping at a defined location relative to the position of the gas inlet is desirable in order to prevent subsequent entrainment of the squirting droplets through the flow in the gas outlet or in the dip tube and thus on the cyclone clean. Therefore, the rejection element advantageously has the special geometric design or manner of length increase in coordination with the prevailing vortex flow formation and thus the cyclone geometry.

In a further advantageous embodiment, the rejection element has at least one drip edge. In this embodiment, the height or longitudinal extent of the rejection element abruptly decreases at one point. In this case, the rejection element expediently has a minimum height (hs _m i _n ) and a maximum height (hs _max ), which are arranged one above the other when viewed in the vertical direction. The free edge preferably runs helical or spiral from the minimum height (hs _m i _n ) in the direction of the maximum height (hs _max ). Between both, ie the minimum height (hSπiin) and the maximum height (hs _ma χ), the free edge is perpendicular, ie parallel to the central axis, so that the arranged in this area free edge can be referred to as a trailing edge. By means of this advantageous embodiment, the targeted dripping is further improved.

In a further preferred embodiment, the rejection element may have two drip edges, which are arranged diametrically opposite relative to the central axis of the cyclone. In this advantageous embodiment, the rejection element has two circular section-like wall sections which are diametrically opposed to the central axis. te, whose maximum height (hs _max ) and minimum height (hs _m i _n ) are each arranged on a plane, wherein the respective minimum height (hs _m i _n ) abruptly decreases to the respective maximum height (hs _ma χ) the desired run-off edge is formed. The free edge extending between the respective wall sections extends continuously inclined from the respective minimum height (hs _m i _n ) to the respective maximum height (hs _max ), wherein the diametrically opposite, continuously inclined free edges are inclined in opposite directions.

In a further preferred embodiment, the rejection element has a plurality of drip edges, so that the rejection element is executed at its free edges quasi sawtooth-like. Here, too, the respective minimum height (hs _m i _n ) abruptly decreases to the respective maximum height (hs _max ) for the formation of the respective run-off edge.

In the advantageous embodiments described above, the rejection element is arranged quasi as a hollow cylinder between an outer wall of the cyclone and an imaginary extension of the gas outlet into the cyclone or between the outer wall of the cyclone and the immersion tube protruding into the interior of the cyclone and connected to the cover. The respective different embodiments can be advantageously produced by means of simple tools as plastic injection molded parts.

In a further preferred embodiment, the rejection element can be designed as a segment-like segment which extends from the lid in the direction of the cone-shaped region. In another advantageous embodiment, the gas inlet is arranged in the lower region of the cyclone, that is to say in the vicinity of its cone-shaped region. Here, the gas inlet is positioned at a defined distance from the lid. It is expedient in this case if the rejection element is connected to the conical region, wherein the rejection element has a cutout, so that a free edge is formed. In this advantageous embodiment, the length hs of the rejection element can be minimally equal to zero (hs _m i _n = 0) in order to ensure removal of the separated oil by the oil drain of the cyclone. Furthermore, in this case, the height of the rejection element may also abruptly decrease from hs _ma χ to hs _ra i _n to form the trailing edge. The dimensioning of the minimum height and the maximum height here refers to the point of attachment of the rejection element to the conical region of the cyclone.

In a preferred embodiment, the free edge extends from the maximum height hs _max to the minimum height hs _m i _{n in a} perspective manner quasi wing-like.

The gas inlet can not only be made round, but have all suitable geometrical configurations. For example, the gas inlet can be made square.

Overall, with the different configurations and arrangements of the rejection element, an improved oil-separating effect, in particular in the case of coarse oil in the form of entrained drops and splashes, is achieved even with an inclined position of the oil separator. It also improves the fine oil separation effect. The respective deflector element with its varying length can, with appropriate adaptation, be advantageously used in different cyclone configurations. used to reduce Ölmitreißneigung. For example, an application in parallel cyclones is conceivable.

Oil recirculation of the separated oil may e.g. via a siphon or, for example, via an oil tank with oil return valve.

Further advantageous embodiments of the invention are disclosed in the subclaims and the following description of the figures. Show it:

1 shows a cyclone with a rejection element in a perspective view,

FIG. 2 shows the cyclone from FIG. 1 with a further embodiment of the rejection element, FIG.

3 shows the cyclone from FIG. 1 with a further embodiment of the rejection element,

4 shows the cyclone from FIG. 1 with a further embodiment of the rejection element,

Fig. 5 shows the cyclone of Figure 1 with a further embodiment of the rejection element, and

6 shows a cyclone with a gas inlet at the bottom and a further embodiment of the deflecting element in a perspective view.

In the different figures, the same parts are always provided with the same reference numerals, which is why these are usually described only once. FIG. 1 shows a cyclone 1 of an oil separator for de-oiling crankcase ventilation gases (blow-by-gas) of an internal combustion engine. The cyclone 1 has a gas inlet 2, wherein the cyclone 1 is associated with a cover 3. In the cover 3, a gas outlet 4 is arranged, which projects somewhat into the interior 7 of the cyclone 1 in the embodiment shown in Figure 1 as a dip tube 6. The dip tube 6 or the gas outlet 4 is arranged concentrically around a central axis X of the cyclone 1 around. In the interior 7 of the cyclone 1, a rejection element 9 is arranged. The rejection element 9 is viewed in the circumferential direction of the cyclone 1 with respect to the cover 3 with varying longitudinal extent.

The cyclone 1 has a cylindrical region 11, which is closed at the top by the cover 3, and a conical region 12 adjoining the cylindrical region 11 at the bottom. The conical region 12 opens with its conical tip directed away from the cover 3 into an oil outlet 13.

The rejection element 9 has a free edge 16, which is designed with respect to the cover 3 in the circumferential direction of the cyclone 1 with varying lengths or heights.

The deflector 9 is arranged concentrically around the central axis X of the cyclone 1 between its wall and the dip tube 6 and has a quasi-hollow cylindrical configuration. In a preferred embodiment, the deflector 9 is connected to the lid 3, wherein a cohesive connection may be provided. But it is also possible a one-piece production of the lid 3 with the rejection element 9 and possibly with the dip tube 6 and the gas outlet. 4 With its lid 3 opposite free edge 16, the deflector 9 extends in the direction of the cone-shaped portion 12th

At its free edge 16, the deflector element 9 has a course which resembles a hollow cylinder cut off obliquely. In this case, the rejection element 9 advantageously has a minimum height (hs _m i _n , referred to by reference numeral 17 in the figures 1 to 5) and a maximum height (hs _max , in FIGS. designated by the reference numeral 18), which are arranged diametrically opposite to the central axis X of the cyclone 1. In this embodiment, the deposited on the rejection element 9 drops run on its outer wall to the free edge 16.

FIG. 2 shows a further embodiment of the deflector element 19, which has at least one drip edge 21. In this embodiment, the height or longitudinal extension of the Abweiselements 19 decreases abruptly at one point, so that a drain edge 23 is formed. Expediently, the rejection element 19 has a minimum height (hs _m i _n ) and a maximum height (hs _max ), which are arranged one above the other when viewed in the vertical direction. The free edge 16 preferably runs helically or spirally from the minimum height (hs _m i _n ) in the direction of the maximum height (hs _max ). Between the two, ie the minimum height (hs _m i _n ) and the maximum height (hs _max ), the free edge 16 runs perpendicular, ie parallel to the central axis X, so that the free edge 16 arranged in this region is referred to as the discharge edge 23 can.

FIG. 3 shows a further embodiment of the deflector element 24, which has two drip edges 26, 27, which relative to the central axis X of the cyclone 1 are arranged diametrically opposite one another. In this embodiment, the rejection element 24 has two circular section-like wall sections 28 lying diametrically opposite the central axis X whose maximum height (hs _max ) and minimum height (hsmin) are each arranged on one plane, wherein the respective minimum height (hs _m i _n ) respective maximum height (hs _max ) decreases abruptly to form the drainage edge 23. The running between the respective wall sections 28 free edge 16 in this case runs continuously inclined from the respective minimum height (hs _ra i _n ) to the respective maximum height (hs _ma χ), wherein the diametrically opposed continuously sloping free edges 16 are inclined in opposite directions. In the embodiment according to FIG. 3, the dip tube 6 does not protrude into the cyclone 1 by way of example.

Figure 4 shows a further embodiment of the Abweiselements 29, which has a plurality of Abtropfkanten 31, so that the Abweiselement 29 is carried out at its free edges 16 quasi sawtooth. Here, too, the respective minimum height (hs _m i _n ) decreases abruptly to the respective maximum height (hs _max ), in order to form one of the several trailing edges 31 in each case. Of course, the illustrated number of drip edges 31 is only exemplary and not intended to be limiting; it may also be provided more or less dripping edges 31.

The different design Abweiselemente 9, 19, 24 and 29 in the embodiments according to Figures 1 to 4 are quasi a hollow cylinder between an outer wall of the cyclone 1 and an imaginary extension of the gas outlet 4 into the cyclone 1 or between the outer wall of the cyclone 1 and into the interior 7 arranged the cyclone protruding dip tube 6 and connected to the lid 3.

FIG. 5 shows a further embodiment of the deflection element 32, which is designed as a segment segment-like segment which extends from the cover 3 in the direction of the conical region 12. Furthermore, in contrast to FIGS. 1 to 4, FIG. 5 shows a quadrangular gas inlet 2.

FIG. 6 shows an embodiment in which the gas inlet 4 is arranged in the lower region of the cyclone 1, that is to say in the vicinity of the cone-shaped region 12. Here, the gas inlet 4 is positioned at a defined distance from the lid 3. Furthermore, a further embodiment of the deflector element 33 is shown, which is connected to the conical region 12, wherein the deflector element 33 has a cutout 34, so that the free edge 16 is formed. In this embodiment, the length hs of the rejection element 33 may be minimal (denoted by reference numeral 36 in FIG. 6) equal to zero. Furthermore, the height of the rejection element 33 in this case can also abruptly decrease from hs _max (denoted by the reference numeral 37 in FIG. 6) to hs _m i _{n in} order to form a drainage edge 23. The dimensioning of the minimum height and the maximum height here refers to the attachment point of the rejection element 33 with the conical region 12 of the cyclone. Nevertheless, the free edge 16 with respect to the lid 3 has a varying longitudinal extent or height. Here, the free edge 16 runs from the maximum height hs _max to the minimum height hs _m i _{n in a} perspective manner in a wing-like manner.

Claims

Claims:

An oil separator for de-oiling crankcase ventilation gases of an internal combustion engine, the oil separator comprising at least one cyclone (1) having a gas inlet (2), wherein the cyclone (1) is associated with a cover (3) in which a gas outlet ( 4, 6) is arranged, and wherein the cyclone (1) in its interior (7) is associated with a rejection element (9, 19, 24, 29, 32, 33), characterized in that the rejection element (9, 19, 24, 29, 32, 33) seen in the circumferential direction of the cyclone (1) relative to the lid (3) is designed with varying longitudinal extents.

2. Oil separator according to claim 1, characterized in that the deflector (9, 19, 24, 29, 32, 33) has a free edge (16), which relative to the cover (3) in the circumferential direction of the cyclone (1) seen is designed with varying lengths or heights.

3. Oil separator according to claim 1 or 2, characterized in that the rejection element (9, 19, 24, 29, 33) in the interior (7) of the cyclone (1) concentrically around the central axis (X) is arranged to extend around.

4. Oil separator according to one of the preceding claims, characterized in that the deflector element (9) at its free edge (16) has a course which is substantially similar to a skewed cylinder.

5. Oil separator according to one of the preceding claims, characterized in that the deflecting element (9) relative to the lid (3) has a minimum height and a maximum height, relative to the central axis (X) of the cyclone (1) arranged diametrically opposite one another are.

6. Oil separator according to one of claims 1 to 3, characterized in that the deflector element (19) has at least one drip edge (21), wherein the deflector element (19) relative to the lid (3) has a minimum height and a maximum height, which are arranged one above the other in the height direction.

7. Oil separator according to claim 6, characterized in that the free edge (16) preferably helically or spirally from the minimum height in the direction of the maximum height, wherein the free edge (16) between the two parallel to the central axis (X), so that a drainage edge (23) is formed.

8. Oil separator according to one of claims 1 to 3, characterized in that the deflector element (24) has two Abtropfkanten (26, 27), which are arranged diametrically opposite relative to the central axis (X) of the cyclone (1).

9. Oil separator according to claim 8, characterized in that the deflector (24) has two to the central axis (X) diametrically opposite wall portions (28) which are executed in a circle-section, the minimum height and maximum height are each arranged on a plane, wherein the respective minimum height decreases abruptly to the maximum height, so that the free edge (16) is formed here as a discharge edge (23).

10. Oil separator according to claim 9, characterized in that between the respective wall sections (28) extending free edge (16) extends continuously inclined from the respective minimum height to the respective maximum height.

11. Oil separator according to one of claims 1 to 3, characterized in that the deflector element (29) has a plurality of Abtropfkanten (31), so that virtually a sawtooth-like course of the free edge (16) is formed with the trailing edge (23).

12. Oil separator according to one of claims 1 or 2, characterized in that the deflector element (32) is designed as a segment-like segment extending from the lid (3) with its free edge

(16) extends in the direction of the conical region (12).

13. Oil separator according to one of claims 1 to 3, characterized in that the rejection element (33) is connected to a conical region (12) of the cyclone (1), wherein the rejection element (33) has a cutout (34), wherein the free edge (16) is virtually wing-like and wherein a run-off edge (23) is formed.