EP1090210B1 - Method for removing oil from crankcase ventilation gases and devices for implementing said method - Google Patents

Description

The present invention relates to a method for deoiling of crankcase ventilation gases of an internal combustion engine, being an oil separator such as a Cyclone, through which the crankcase ventilation gases flow and the oil droplets contained in it Oil separating element to be separated.

The invention further relates to a device for carrying it out of the process, with one of crankcase ventilation gases flowed through an internal combustion engine Oil separator, such as a cyclone.

A procedure of the type mentioned at the outset is fundamental e.g. known from DE 31 28 470 A. To carry out Suitable devices of the method are from the practical Operation from a variety of use cases known. The oil separation from the crankcase ventilation gases known separation elements used, in most cases cyclones have two determinants Company sizes, namely the separation performance and the differential pressure from the volume flow of the passed Crankcase ventilation gas, the so-called Blow-by gases, depend. This results from operational reasons a volume flow range in which both the separation performance as well as the differential pressure of the separating element optimally to the requirements of the internal combustion engine are coordinated.

The volume flow of the crankcase ventilation gas is depending on operating parameters, such as load status and Speed, the associated internal combustion engine and from the state of wear of the same. This results in the Operation of an internal combustion engine such a large volume flow range, that this disadvantageously with a single Separator can not be covered because the optimal operating state of the separating element only observed in a small area. In other areas e.g. decreases the separation performance at low volume flows below a desired level or at correspondingly larger volume flows exceed that which arises Differential pressure a still permissible value.

It is therefore the object of the invention to provide a method and a device for de-oiling crankcase ventilation gases to be specified for all company sizes of Internal combustion engine work in the optimal range.

• daß der Volumenstrom der Kurbelgehäuseentlüftungsgase in mindestens zwei Teilvolumenströme aufgeteilt wird,
• daß der Volumenstrom nach der Teilung durch mindestens zwei Ölabscheideelemente geleitet wird und
• daß die Größe der mindestens zwei Teilvolumenströme abhängig von der Größe des Volumenstroms geregelt wird.

The part of the task using the method is solved with a generic method with the characterizing features of patent claim 1. The method according to the invention is characterized in that

• that the volume flow of the crankcase ventilation gases is divided into at least two partial volume flows,
• that the volume flow after the division is passed through at least two oil separating elements and
• that the size of the at least two partial volume flows is regulated depending on the size of the volume flow.

This advantageously ensures that at low volume flows only one separating element by appropriate regulation is applied and that with large volume flows applied to the at least two separating elements become. It is of course possible to have three or four or use correspondingly more separating elements that are each regulated so that the partial volume flow flowing to them optimally cleaned of the oil droplets can. The method according to the invention is therefore advantageous achieved the separation performance and the differential pressure are always kept in the optimal range can, even in extreme operating conditions such as overrun and / or heavy wear, the internal combustion engine.

The solution of the part of the device Task is carried out with a generic device the characterizing features of claim 2. The The device according to the invention is characterized by Means for dividing the volume flow into at least two Partial volume flows, at least two downstream oil separation elements and at least one rule element that in Depending on the size of the volume flow flowing to it regulates at least one of the partial volume flows. With This device can be the method specified above practically perform.

According to a first embodiment of the device, that the at least two downstream oil separating elements are connected in parallel and that the Oil separation elements upstream a common control element is connected upstream, the volume flow of the crankcase ventilation gases depending on its size divided into the at least two partial volume flows and this feeds the at least two oil separating elements.

The advantage of this solution with a single common The control element lies in the relatively simple structure.

A second embodiment of the device provides that the at least two downstream oil separation elements are connected in parallel and that the oil separating elements upstream each have their own control element is, depending on the size of a partial stream flowing to it Oil separating element regulates. In this second embodiment is a separate control element for each oil separator element necessary, but they can each be advantageous because of the smaller partial electricity volumes to be absorbed in in most cases smaller than the first embodiment be executed.

For a further development of the previously specified configuration the device is intended to be upstream an additional common control element from the control elements is present, which is the volume flow of the crankcase ventilation gases depending on its size divided into the at least two partial volume flows and this the at least two downstream control elements passes, with control commands from the common control element feedable to the downstream control elements are. The common control element is more suitable here Manner, e.g. through electrical control signal lines, with connected to the downstream several control elements in such a way that control commands from the common control element too the downstream control elements can be forwarded and in particular control signals for opening or closing can be forwarded.

In a further embodiment of the device strikes the invention that the at least two downstream Oil separator elements are connected in parallel and that the oil separating elements each have a flow control element is connected in parallel, the oil separating elements each flow through one of the partial flows are, the size of each by the assigned control element is adjustable. In this version, the number is the control elements equal to the number of oil separator elements; the control elements are advantageous here but not fully flowed through by the partial flows, whereby in some cases an even smaller construction of the control elements is possible.

Another embodiment of the device according to the invention is characterized in that the at least two downstream oil separator elements connected in series are and that the oil separating elements upstream respectively a control element is connected upstream, each control element depending on the volume flow flowing to it divides it into two sub-streams, one of which in each case one partial stream downstream of the control element Oil separating element flows in and each other substream flows into a bypass line that is on passes the downstream oil separator. at this version of the device can have a too large volume flow bypassed the oil separators if this is permitted in some operating conditions or is desired.

For all embodiments of the device explained above can in a first, simple version, the control element be a passive element that is immediate over the volume flow or over one exerted by this Force can be actuated. This will on the one hand simple and inexpensive construction and on the other hand achieved high reliability in operation.

Alternatively, the control element can be an active element be that according to a by measuring the volume flow obtained control signal is actuated. This execution requires a slightly higher technical level Effort, but allows a more precise regulation and enables a stronger influence e.g. on the course of Generally characteristics.

With regard to the aforementioned measurement of the volume flow sees a first development of the device before that a measuring device for measuring the volume flow one through which an electric current flows Includes hot wire and that the control element can be actuated electrically is. Both measurements are advantageous here of the volume flow and the actuation of the control element electrical, so a simple conversion of Measuring signals in control signals on a purely electrical way is possible.

An alternative embodiment suggests that a measuring device a Venturi pressure sensor to measure the volume flow comprises and that the control element mechanically, preferably via a valve tappet Control element acting membrane, is actuated. This Execution has the advantage that both the measurement and. also the actuation of the control element on a purely mechanical basis Paths are made so that a conversion from mechanical Measured values in electrical signals or vice versa from electrical signals to mechanical manipulated variables is not necessary.

To make the device compact and clear as well as easy to assemble to hold, it is preferably provided that the control element directly in the gas inlet of the associated oil separator is arranged and that by means of the control element, the inlet cross section of the oil separating element between an open and a closed position, preferably continuously or in several stages, is changeable.

An equivalent, alternative version of the device suggests that the control element be immediate arranged in the gas outlet of the associated oil separating element and that by means of the control element, the gas outlet cross section of the oil separating element between one Open and closed position, preferably continuously or in several stages, is changeable.

To in the last described embodiment of the device to avoid that cleaned when the gas outlet is closed Unwanted gas through an oil outlet the oil separating element escapes, is also provided that in addition to the control element each immediately in the oil outlet of the associated oil separator element an additional control element is arranged that by means of Additional control element of the oil outlet cross section of the oil separating element between an open and a closed position, preferably continuously or in several stages, is changeable and that the control element and the additional control element coupled together adjustable are. This coupling of control element and additional control element ensures that only when the gas outlet is open also the oil outlet is open and that when closed Gas outlet is also closed the oil outlet.

In a concrete form of the coupled unit Control element and additional control element is proposed that the control element and the additional control element each one by weight or spring force in the closing direction include preloaded valve ball, the valve ball of the control element has a larger diameter than the valve ball of the additional control element and where the two valve balls through a coupling element for common Adjustment are interconnected. hereby becomes a common and like-minded movement the valve balls and thus a coupled adjustment guaranteed by control element and additional control element. The coupling element is in its simplest design a thin and connecting the two valve balls lightweight rod with the two valve balls vividly forms an asymmetrical dumbbell.

Figur 1

eine erste Ausführung,

Figur 2

eine zweite Ausführung,

Figur 3

eine dritte Ausführung,

Figur 4

eine vierte Ausführung und

Figur 5

eine fünfte Ausführung der erfindungsgemäßen Vorrichtung, jeweils in Form eines Blockdiagramms,

Figur 6

eine Ausführung der Vorrichtung mit zwei parallel geschalteten Zyklonen als Ölabscheideelemente und mit einem Regelelement, in schematischer Darstellung,

Figur 7

einen Zyklon mit vorgeschaltetem Regelelement als Teil der Vorrichtung aus Figur 6, im Querschnitt und

Figur 8

einen Zyklon als Teil der Vorrichtung, im Längsschnitt.

Various embodiments of the invention will now be explained in more detail with reference to a drawing. The figures in the drawing show:

Figure 1

a first execution,

Figure 2

a second version,

Figure 3

a third version,

Figure 4

a fourth version and

Figure 5

a fifth embodiment of the device according to the invention, in each case in the form of a block diagram,

Figure 6

an embodiment of the device with two cyclones connected in parallel as oil separating elements and with a control element, in a schematic representation,

Figure 7

a cyclone with upstream control element as part of the device of Figure 6, in cross section and

Figure 8

a cyclone as part of the device, in longitudinal section.

With reference to Figure 1 flows in the direction of the arrow Volume flow 2 of the crankcase ventilation gases to one common control element 3 ', which the volume flow 2nd divided into up to four sub-streams 21, 22, 23, 24, the each flow through an oil separator 1, whereupon the partial flows through appropriate cable routing reunite to a de-oiled volume flow 2, the derived to the right in Figure 1 in the usual way e.g. in the intake tract of the associated internal combustion engine. Depending on the current size of the incoming Volume flow 2 are more or less many of the four available oil separators 1 used. The partial streams 21 to 24 must of course are not the same with each other, but they can be certain operating states of the associated internal combustion engine his.

In Figure 2, a volume flow 2 through branching divided into four sub-streams 21 to 24, each Partial current flows through a control element 3 and then through an oil separator 1, whereupon the four de-oil Streams 21 to 24 are merged again.

In Figure 3, a volume flow 2 is again in four sub-flows 21 to 24 divided, after which each partial stream 21 to 24 again divided into two flow paths by a pair of oil separators connected in parallel 1 and a control element 3 flows, after which the two flow paths are combined and also the four partial streams 21 to 24 again to a common de-oiled volume flow 2 flow together.

In Figure 4, the volume flow 2 initially flows in its Entirety through a common first control element 3 ', after leaving it into four sub-streams 21 to 24 to be divided, after which each partial stream is divided by a Control element 3 flows and then through an oil separator 1, whereupon the four sub-streams become one again common de-oiled volume flow 2 are combined. In Figure 4 are signal transmission means 5, e.g. electrical Control signal lines, between the common first Control element 3 'and the four control elements 3, the Control signals transmitted, indicated by dashed lines. It can be seen that the common control element 3 'with each individual downstream control element 3 through the signal transmission means 5 in connection stands.

Figure 5 shows an embodiment in which the common Volume flow 2 first passed into a control element 3 in which it is divided into two sub-streams. The a partial flow flows down in FIG. 5 and then to the right through a bypass line 4, so touches no oil separator. The other partial flow flows through an oil separating element 1 and further to a downstream one Control element 3, again a division as done in the first stage. A first partial flow flows into the bypass line 4 and the other Partial flow through an oil separator 1 and from there continue to a third control element 3. This is also done here a division into a partial flow, which in the bypass line 4 flows and another partial flow, which flows through the third oil separating element 1, whereupon he then flows into the common line, which the Volume flow 2 takes up, which also includes the partial flow that has flowed through the bypass line 4 is.

An embodiment is shown in a schematic representation in FIG shown the device, the two connected in parallel Cyclones as oil separators 1 and one has individual control element 3. From the raw side, i.e. from the crankcase one not shown here Internal combustion engine, there is a volume flow 2 from crankcase gas loaded with oil droplets. The volume flow 2 is divided into two partial streams 21, 22. The first partial stream 21 becomes a first one, in FIG. 6 Cyclone 1 shown above through its gas inlet 11 fed. Inside the cyclone 1 takes place in a known manner Way a separation into clean gas and oil, the clean gas leaves the cyclone 1 upwards through a gas outlet 12, while the oil separated by the one provided below Oil outlet 13 flows off.

Since no control element precedes the first cyclone 1 is, this is in operation of the associated internal combustion engine constantly flowed through by gas.

The second cyclone 1 is connected to the second partial stream 22 the crankcase ventilation gases. this Cyclone 1 is the control element 3 upstream, which here by a ball valve preloaded in the closing direction 31 is formed. Due to the preload in Closing direction at low volume flow 2 is the control element 3 closed; only when the Volume flow 2 opens the valve 31 due to the increasing Volume flow, here of partial flow 22, e.g. by a force exerted by the latter on the valve ball. As soon as the control element 3 opens, becomes parallel to the first Cyclone 1 now also the second cyclone 1, which is shown in FIG shown below, from a partial flow of the crankcase ventilation gas flows through. This is how she works Device for both small and large volume flow each in a favorable separation area the cyclones 1.

This also happens with the second, lower cyclone 1 cleaning gas through a gas inlet 11 into the cyclone 1 into it. The cleaned gas leaves through an upward Gas outlet 12 the second cyclone; the separated oil flows down into the oil outlet 13 and is together with that deposited in the first, upper cyclone 1 Oil preferably in the oil pan of the internal combustion engine recycled.

After the two cyclones 1, the partial flows 21, 22 again to a common, now cleaned volume flow 2 merged and derived, preferably in the intake tract of the associated internal combustion engine.

In an embodiment, not shown, the Oil outlets 13 of the oil separating elements 1 in a common Oil collection container, which is located directly on the oil outlets 13 connects. Here is the oil reservoir via a valve, a so-called anti-return valve, connected to the crankcase. That way avoided that the oil outlets 13 of the oil separating elements be subjected to the crankcase pressure. To drain of the collected oil opens the anti-return valve at times so that the oil can drain into the crankcase can. The anti-return valve can also be designed as a siphon his. To prevent an undesirable gas flow through the Oil outlet 13 of the oil separating element 1, the gas inlet or gas outlet closed via the control element 3 is to prevent, this oil outlet 13 has an additional control element 3 '' on opposite the oil outlet 13 can shut off or open the oil reservoir.

In a further embodiment, not shown open the oil outlets 13 of at least two connected in parallel Oil separating elements 1 in their own Oil collection container, each via a non-return valve is connected to the crankcase. Take over here the anti-return valves also function of the aforementioned additional regulations 3 ''.

FIG. 7 of the drawing shows an exemplary embodiment in cross section for a cyclone 1 with an upstream Control element 3 in the form of a valve 31. The valve 31 is here as a prefabricated unit in a pipe socket, which in the course of the partial flow 22 to the gas inlet of the Cyclones 1 is installed, pressed in here. By means of a The spring is preloaded on a valve plate in the closing direction. Through the partial flow 22, if the partial flow 22 is sufficiently large, the valve plate from Valve seat can be lifted against the force of the spring, so that the partial flow 22 through the control element 3 through to the gas inlet 11 of the cyclone 1 and then flows through the cyclone 1. At the center of the cyclone 1 part of the gas outlet 12 can still be seen.

Figure 8 of the drawing shows an example of a cyclone 1 as an oil separator, in which a control element 3 in the gas outlet 12 and an additional control element 3 '' is provided in the oil outlet 13. The gas to be cleaned passes through the gas inlet at the top left of cyclone 1 11 inside the cyclone 1 and is in this set in a rotating flow. The oil droplets due to the centrifugal force inner surface of the cyclone 1 and flow down towards the oil outlet 13. That of the oil droplets freed, cleaned gas flows in the center of the cyclone 1 upwards through a central dip tube 12 'in the direction to the gas outlet 12.

The control element 3 in the gas outlet 12 is here by a Valve ball 32 formed on one at the top of the dip tube 12 'molded annular valve seat rests. In the area immediately above the oil outlet 13, a second valve ball 33 is arranged, which in their lower position closes the oil outlet 13, like this is shown in Figure 8. The valve ball 32 of the control element 3 and the valve ball 33 of the additional control element 3 '' are straight through a coupling element 34 running thin and light rod, mechanical interconnected so that they can move in Carry out vertical direction together.

In the state shown here, in which the two Valve balls 32, 33 are in their closed position, there is no gas throughput through cyclone 1.

As soon as a sufficiently large volume flow at the gas inlet 11 of the cyclone 1 is obtained by means of that Differential pressure between the inside of the Cyclones 1 and the area of the gas outlet 12 above the valve ball 32 raised this upwards. hereby is the gas outlet 12 for a flow through the cleaned gas opened. By moving the valve ball 32 upward, the lower valve ball 33 around also moved up the same path, causing the at the lower end of the cyclone 1 oil outlet 13 is also opened. So separated oil can flow down through the oil outlet 13.

So that the pressure difference also the desired lifting of the Valve balls 32, 33 can cause is the upper valve ball 32 with a larger diameter than the lower valve ball 33. At the same pressure difference between the inside of the cyclone on the one hand and the areas of the outside of the valve balls 32, 33 Cyclones always result in a resulting, after Force directed above that opens the control element 3 and 3 ''.

Claims (17)

1. Method for the deoiling of crankcase ventilation gases of a combustion engine, in which the crankcase ventilation gases flow through an oil separator element (1) in the manner of a cyclone, thereby separating, in the oil separator element (1), the oil droplets contained in said gases,
   characterized in that

   the volume flow (2) of the crankcase ventilation gases is split into at least two partial volume flows (21, 22, 23, 24);

   the volume flow (2), after having been split, is guided through at least two oil separator elements (1);

   the magnitude of the at least two partial volume flows (21 to 24) is controlled in relation to the magnitude of the volume flow.
2. Apparatus for the implementation of the method according to claim 1, with an oil separator element (1) through which crankcase ventilation gases of a combustion engine flow in the manner of a cyclone,
   characterized by

   means for splitting the volume flow (2) into at least two partial volume flows (21, 22, 23, 24);

   at least two downstream oil separator elements (1); and

   at least one control element (3, 3') that controls at least one of the partial volume flows (21, 22, 23, 24) in relation to the magnitude of the incoming volume flow (2).
3. Apparatus according to claim 2, characterized in that

   the at least two downstream oil separator elements (1) are in a parallel arrangement; and

   the oil separator elements (1) have a joint upstream control element (3') that splits the volume flow (2) of the crankcase ventilation gases into at least two partial volume flows (21 to 24) in relation to the magnitude of the volume flow (2) and guides the partial volume flows to the at least two oil separator elements (1).
4. Apparatus according to claim 2, characterized in that

   the at least two downstream oil separator elements (1) are in a parallel arrangement; and

   the oil separator elements (1) each have their own upstream control element (3), each of which controls the downstream oil separator element (1) in relation to the magnitude of an incoming partial flow (21 to 24).
5. Apparatus according to claim 4, characterized in that an additional joint control element (3') is arranged upstream of the control elements (3) and splits the volume flow (2) of the crankcase ventilation gases into at least two partial volume flows (21 to 24) in relation to the magnitude of the volume flow (2) and guides these two partial volume flows to the at least two downstream control elements (3), with the joint control element (3') being capable of communicating control commands to the downstream control elements (3).
6. Apparatus according to claim 2, characterized in that

   the at least two downstream oil separator elements (1) are in a parallel arrangement; and

   a control element (3) is arranged in parallel to each of the oil separator elements (1) in accordance with the flow, wherein one of the partial flows (21 to 24) each can flow through each of the oil separator elements (1), with the magnitude of the flow being controllable by the corresponding control element (3).
7. Apparatus according to claim 2, characterized in that

   the at least two downstream oil separator elements (1) are in a serial arrangement; and

   the oil separator elements (1) each have an upstream control element (3), wherein each control element (3) splits the incoming volume flow into two partial flows in relation to the incoming volume flow, such that one of these two partial flows flows to the oil separator element (1) downstream of the control element (3) and the other partial flow flows into a bypass line (4) bypassing the downstream oil separator element (1).
8. Apparatus according to anyone of the claims 2 to 7, characterized in that the control element (3) is a passive element that can be actuated directly via the volume flow (2, 21 to 24) or via a force exerted by this volume flow.
9. Apparatus according to anyone of the claims 2 to 7, characterized in that the control element (3) is an active element that can be actuated according to a control signal obtained by measuring the volume flow (2, 21 to 24).
10. Apparatus according to claim 9, characterized in that a measuring instrument for measuring the volume flow (2, 21 to 24) comprises a hot wire, through which an electric current flows, and in that the control element (3) can be actuated electrically.
11. Apparatus according to claim 9, characterized in that a measuring instrument for measuring the volume flow (2, 21 to 24) comprises a Venturi pressure transducer and in that the control element (3) can be actuated mechanically, preferably via a diaphragm acting upon a valve tappet of the control element (3).
12. Apparatus according to anyone of the claims 2 to 11, characterized in that each control element (3) is arranged directly in the gas inlet (11) of the corresponding oil separator element (1) and in that the cross-section of the inlet of the oil separator element (1) can be changed from an open position to a closed position and vice versa by means of the control element (3), preferably continuously or in several steps.
13. Apparatus according to anyone of the claims 2 to 11, characterized in that each control element (3) is arranged directly in the gas outlet (12) of the corresponding oil separator element (1) and in that the cross-section of the gas outlet of the oil separator element (1) can be changed from an open position to a closed position and vice versa by means of the control element (3), preferably continuously or in several steps.
14. Apparatus according to claim 13, characterized in that, in addition to each control element (3), an additional control element (3") is arranged directly in an oil outlet (13) of the corresponding oil separator element (1); in that the cross-section of the oil outlet of the oil separator element (1) can be changed from an open position to a closed position and vice versa by means of the additional control element (3"), preferably continuously or in several steps; and in that the control element (3) and the additional control element (3"), being coupled to one another, can be readjusted jointly.
15. Apparatus according to claim 14, characterized in that the control element (3) and the additional control element (3") each comprise a valve ball (32, 33) that is preloaded in closing direction by a weight or spring force, wherein the diameter of the valve ball (32) of the control element (3) is larger than the diameter of the valve ball (33) of the additional control element (3") and wherein the two valve balls (32, 33) are connected to one another by means of a coupling element (34) permitting their joint readjustment.
16. Apparatus according to anyone of the claims 12 to 15, characterized in that the oil outlets (13) of at least two oil separator elements (1) in a parallel arrangement terminate in a joint oil collection container that is connected to the crankcase via a valve, wherein the oil outlet of at least one oil separator element (1) comprises an additional control element (3") that changes the cross-section of the oil outlet from an open position to a closed position and vice versa in direction of the oil collection container, preferably continuously or in several steps.
17. Apparatus according to anyone of the claims 12 to 15, characterized in that the oil outlets (13) of at least two oil separator elements (1) in a parallel arrangement each terminate in their own oil collection container each of which is connected to the crankcase via a valve.

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