EP2297434A1

EP2297434A1 - Device and method for ventilating a crankcase

Info

Publication number: EP2297434A1
Application number: EP09768885A
Authority: EP
Inventors: Armin KÖLMEL; Jochen Loos
Original assignee: Bayerische Motoren Werke AG
Current assignee: Bayerische Motoren Werke AG
Priority date: 2008-06-24
Filing date: 2009-05-27
Publication date: 2011-03-23
Anticipated expiration: 2029-05-27
Also published as: ES2373778T3; ATE532948T1; WO2009156036A1; EP2297434B1; DE102008029904A1

Abstract

The invention relates to a device and a method for ventilating a crankcase (10) of a supercharged internal combustion engine, wherein a plurality of collecting chambers (28, 30) for ventilation gases are provided, having individual oil separators (88, 90) associated therewith. Contrary to full load operation, during partial load operation the ventilation gas of a collecting chamber (28) is fed to a non-associated oil separator (90) and is ventilated using the same.

Description

Device and method for crankcase ventilation

The invention relates to an apparatus and a method for Kurbelgehauseentluftung and return the Entluftungsgase in the combustion chamber of a supercharged internal combustion engine

In the operation of internal combustion engines, in particular reciprocating engines, combustion gases between the cylinders and the piston rings can escape into the spa. These gases are referred to as blow-by gases and can build up considerable pressure within the body of the spa so that venting of the body is required. By-gases in the crankcase are loaded with motor oil, which is why they should not be discharged into the environment and usually pass through an oil separator to finally be fed into the intake manifold of the internal combustion engine From here, the gases are directed back into the combustion chambers of the cylinder

In order to regulate the pressure in the Kurbeigehause to a constant value as possible, pressure control valves or variable throttles with or without Rückschlagfunktion zabe PCV valves (positive crankcase ventilation) can be provided About such control valves, the negative pressure in the intake tract is used to Suction gases from the crankcase When a turbocharger is provided, the extracted gas is sucked in Teugastbetπeb the downstream of the turbocharger in the intake, and at full load upstream of the turbocharger in the intake check valves at full load must prevent the pressure on the so-called part-load venting in the Kurbeigehause is transmitted

The extraction of the gases takes place either in the area of the bottom of the

In the case of extraction in the area of the cylinder head, a distinction is made, in particular, between the arrangement of the collection chamber in the cylinder head itself or in a valve cover surrounding the cylinder head. The collection chambers are, moreover, the spaces in which the de-aeration gas is present before the extraction is From EP 1 310 639 A1 a Kurbelgehauseentluftung in a V-engine known each cylinder row is associated with a turbocharger, wherein a common intake manifold is provided for both rows In addition, there is a common oil separator for both rows of cylinders, said provided in the cylinder head cover collecting chambers on a connecting line are coupled to each other The gas is then introduced in Teufastbetπeb downstream of the throttle cap in the intake and at full load in an air supply pipe upstream of the turbocharger

Another variant of a Kurbelgehauseentluftung a V-engine provides for each cylinder row its own turbocharger and a separate Olabscheider At Olabscheidem, especially gravity separators, the degree of separation is partly dependent on the throughput There are therefore Olabscheider, where individual stages (in multiple cyclone individual Cyclones) can be connected via switching elements Such switching elements usually consist of a spring and a, operated by the spring closure element

The object of the invention is to provide a simpler device for Kurbelgehauseentluftung and a method for this purpose

The device according to the invention for crankcase ventilation and jerk guidance of the vent gases (called blow-by gases) in the combustion chamber of a supercharged internal combustion engine has several manifolds for exhaust gases associated with the turbine housing and one or more cylinders. These manifolds can be provided in the turbine housing or on the cylinder head side At least one turbocharger is arranged in a suction line, whereby several suction lines can also be provided. In addition, each collecting chamber is assigned at least one separate oil separator. A partial gravity discharge line leads from an oil separator to the downstream of the turbocharger to the suction line into which it flows each Entlabscheider a Vollastruckfuhrleitung provided for Entluftungsgas, the upstream of the turbocharger mouths in the intake In full-load operation, de-aeration gas flows through each collecting chamber on the associated, own Olabsc heider in the intake pipe At least in part load bed the collecting chambers but stromungsmaßig are interconnected, and Entluftungsgas is guided by at least two collection chambers via the Olabscheider a collection chamber in the intake

The inventive device provides that in part-load operation less

Olabscheider in operation, so that the then operating oil separator achieve a higher throughput and Olabscheidegrad than in partial load operation Thus, additional switching elements are unnecessary Preferably, the invention

Device thus no switchable oil separator

According to the preferred embodiment, a plurality of rows of cylinders are provided, and each row of cylinders has its own collection chamber. As already explained, these collection chambers can be sections of the crankcase or be associated with the cylinder head and lie in its area

As also already explained, the collecting chambers must be current-connected with each other. This can preferably take place via the common crankcase, so that additional lines could be omitted

Preferably, a plurality of turbochargers are also provided, each associated with a single or a group of cylinders. According to the preferred embodiment, each row of cylinders (also called a cylinder bank) has its own associated turbocharger

Preferably, an oil separator is assigned to each turbocharger

It should be emphasized that, of course, several oil separators can work in the partial load cycle, but not all of these working oil separators the gas is then branched back to the intake manifolds, too to intake pipes of non-active oil separators

Full-throttle delivery lines may be provided which travel from the oil separators to the intake manifolds of the plurality of turbochargers. These full-load delivery conduits will then direct the gas to the intake manifolds upstream of the turbochargers at full load

According to one embodiment of the invention, one, preferably only one,

Ventilation provided, which leads to a collection chamber and on the Connection of the collecting chambers vented Such a ventilation line enables a so-called winding of the Kurbeigehauses with fresh air, which among other things, the chemical aging of the lubricating oil is reduced In this embodiment, the construction cost of ventilation is very low

Preferably, the aeration line in the oil separator, which does not work in part-load operation, mouth, so that from this, the ventilation is also hereby let the number of terminals or provided with terminals parts reduce

In order to reduce the number of lines, the ventilation line can be the full-load transfer line of the non-working oil separator. This line has, as it were, a double function and is flowed through in two directions, in one direction from the deaeration gas and in the other direction from the fresh air

In order to avoid switchable valves and yet to achieve a clear Stromungsfuhrung in the various load operations, check valves are arranged in the Vollastuckfύhrleitungen These prevent suction via these lines in Teillastbetneb

The check valve in serving as a ventilation line Vollastruckfuhrleitung can be provided with a throttled bypass, which is then vented, although the check valve is actually in the closed position This embodiment can be realized very inexpensive

In the at least one or each partial load line, a throttle unit with backlash function (eg PCV valve) should be arranged with the fresh air supply such PCV valves prevent the backflow of the gases Such PCV valves are available in heatable and unhookable execution About the PCV valves sucked by means of the negative pressure in the intake tract, the Entluftungsgase, in part-load bed

The oil separators are gravity separators, in particular cyclone separators, as already mentioned, preferably even non-switchable cyclone separators The venting takes place according to the preferred embodiment cylinder head side, wherein the collecting chambers may be provided in the cylinder head or in the valve bonnets.

Of course, in the embodiment with venting via the crankcase itself, the collecting chambers can also be sections of the interior of the crankcase that merge into one another. For optimal ventilation and

Ventilation, i. Flushing, it would be beneficial in this context if the

Open lines as far away from each other as possible into the crankcase.

The invention further relates, as already explained, a method for venting a crankcase of an internal combustion engine, in particular a

Reciprocating engine, which has several collecting chambers for venting gases, which are assigned their own oil separator. The procedure provides that in

Partial operation, the venting gases of a collection chamber is guided to an unassigned oil separator and vented through this, whereas in the full load operation, the venting gases of the collecting chambers are vented through their own, each associated oil separator.

Further features and advantages of the invention will become apparent from the following description of a preferred embodiment, which is shown in the single schematic figure.

In the figure, a motor, more specifically, a reciprocating engine one

Internal combustion engine shown. The engine is in this embodiment, a V-type engine with a crankcase 10, which has two rows of cylinders 12, 14. Denoted at 16 are the pistons and at 18 the intake and exhaust valves housed in the cylinder heads 20,22. Each row of cylinders is covered with a so-called. Valve cover 24, 26, wherein the valve bonnets 24, 26 can also merge into one another in one piece.

Between the valve covers 24, 26 and the cylinder heads 20, 22 are each so-called. Collection chambers 28, 30 are provided for vent gases.

These vent gases are contaminated with water, oil from the crankcase 10 and other components blow-by gases 32, which between the

Piston 16 and the cylinders 34, 36 can escape from the corresponding working spaces in the crankcase chamber 38. In the crankcase room 38 these blow-by gases 32 rupture oil 40 at the bottom of the crankcase chamber 38. The resulting vent gas 32 is then in the crankcase chamber 38, where it would generate an overpressure.

The vent gases 32 not only spread in the crankcase chamber 38, but may flow through passages 42, 44 in the cylinders 34, 36 or between the cylinders 34, 36 and the valve bonnets 24, 26 to the cylinder heads 20, 22.

In the illustrated embodiment, a separate collection chamber 28, 30 is provided for the vent gases for each cylinder row 12, 14 between the cylinder heads 22, 24 and the associated valve bonnets 24, 26.

Alternatively, the Sammelkammem 28, 30 could of course also be formed in the area of the cylinder heads 20, 22 and the cylinder head cover, as shown for example in DE 35 09 439 C2.

The collection chambers 28, 30 are interconnected via the crankcase 10 or, more specifically, via the merging passages 42, 44 (e.g., on the facing sides of the cylinders 34, 36). The

Junction is designated 46. In the region of this connection point 46, one of the several outflow openings 48 for the venting gas is also provided. The arrow 50 symbolizes at this point, the venting gas, which flows into the passages 42, 44.

The engine block shown is of course integrated in an air supply and an exhaust system, which will be described in more detail below.

Each cylinder bank 12, 14 is associated with its own intake manifold 52, 54, which is subdivided into several sections, in each of which a separate intake noise damper 56 and a possibly necessary hot-film air mass meter 58 are integrated. Each intake pipe 52, 54 is also associated with its own turbocharger 60, 62, which is integrated in an exhaust pipe 64, 66 and is driven by the exhaust gas.

The turbochargers 60, 62 divide the intake passages 52, 54 into an upstream section 68, 70 and a downstream section 72, 74. In the respective downstream portion 72, 74 are each a throttle valve 76, 78 and a charge air cooler 80, 82 integrated.

In the internal combustion engine, a device for crankcase ventilation and return of the venting gases in the respective combustion chamber 84, 86 of the cylinder 34 and 36 is provided.

This device comprises, inter alia, the collection chambers 28, 30 and at least one own oil cutters 88, 90 assigned to each collection chamber 28, 30.

Preferably, the oil separators 88, 90 are cyclone separators, with no switchable cyclones.

From the oil separator 88, a full return line 92 leads into the upstream section 68 of the intake line 52 for the cylinder bank 12

Vollastrückführleitung 92 is a check valve 94 is integrated, which has a

Bypass with throttle 96 can be bridged. Of course, the bypass with throttle 96 may also be fully integrated into the check valve 94.

The oil separator 90 of the other collection chamber 30 has a from the

Oil separator 90 outgoing gas return line, which divides several times, namely on the one hand in a Vollastrückführleitung 98, in the upstream

Section 70 opens and in which a check valve 99 is seated, and two part throttle return lines 100, 102nd

The part throttle return line 100 is provided with a so-called. PCV valve 104 and opens into the downstream section 72 of the suction line 52, which is not actually assigned to the oil separator 90.

The partial flow return line 102 is also provided with a PCV valve 106 and opens into the downstream section 74 of the suction line 54 associated with the oil separator 90.

The part throttle return lines 100, 102 preferably end after the throttle valves 76, 78 and also preferably after the intercoolers 80, 82nd

In the following, the operation of the crankcase ventilation device and the procedure behind are described in more detail. At full load, the exhaust gases drive the two turbochargers 60, 62, so that in the downstream sections 72, 74, a relatively high pressure prevails. The resulting in the combustion chambers 84, 86 exhaust gases are guided via the exhaust valves 18 to the exhaust pipes 64, 66. Blow-by gases 32, however, reach the crankcase chamber 38, where they also entrain oil 40. The resulting vent gases pass through the outflow openings 48 into the passages 42, 44 and thus into the collection chambers 28, 30 in the region of the cylinder heads 20, 22nd

In the upstream portions 68, 70 there is a negative pressure, so that the vent gases through the oil separator 88, 90 to flow (see arrows in the

Collecting chambers 28, 30). In the oil separators 88, 90 is the retained

Oil is then returned to the collection chambers 28, 30, where it is on the walls of the

Passages 42, 44 along back into the crankcase chamber 38 flows

(see thick arrows 108). The vent gas then flows from the oil separators 88, 90 through the open check valves 94, 99 into the upstream ones

Sections 68, 70 back into the exhaust pipes 64, 66. At full load are the

PCV valves 104, 106 due to the high pressure in the downstream

Sections 72, 74 closed.

At partial load, there is a vacuum in the downstream sections 72, 74 so that the PCV valves 104, 106 are open, whereas the valves 94, 99 are closed.

Since the collection chamber 28 does not have its own, open discharge line in part-load operation, the venting gas of the collection chamber 28 flows through the flow connection (here the passages 42, 44) to the collection chamber 30. Thus, a higher amount of vent gas is sucked through the oil separator 90, which can thus work more effectively ,

This switchover between partial and full load takes place for the venting without additional valve devices. The vent gas then splits downstream of the oil separator 90 and passes through the open PCV valves 104, 106 into the downstream sections 72, 74 of the exhaust conduits 64, 66, respectively.

In partial load operation, fresh air ventilation also takes place, namely ventilation of both the collection chambers 28, 30 and the crankcase. By way of the restrictor 46, fresh air drawn in (symbolized by a broken line parallel to the full return line 92) passes via the full return line 92 into the oil separator 88 and thus into the collecting space 28. From there, the fresh air can supply all the spaces provided with the vent gas Flow through chambers and get to the oil separator 90.

The inventive method thus provides that in partial load operation the

Venting gases of a collection chamber 28 to an unassigned

Oil separator 90 is guided and vented through this, whereas the exhaust gases of the collecting chambers 28, 30 via their own, each associated oil separator 88, 90 are vented in full load operation.

In partial load operation, a higher degree of separation in the oil separator 90 and thus an improvement in efficiency is achieved since separators are normally designed for maximum throughput. The oil separator 90 thus receives twice the amount of deaerating gas including aeration gas and works almost continuously only at maximum throughput. It also results in a lower coking of the intake valves. Since no additional switching elements are needed, resulting in lower costs and a lower weight.

Claims

claims

1. A device for crankcase ventilation and return of the vent gases in the combustion chamber (84, 86) of a supercharged internal combustion engine, with. a plurality of the crankcase (10) and one or more cylinders

(34, 36) associated venturi (28, 30) for vent gases, at least one in a suction line (52, 54) arranged turbocharger (60, 62), a plurality of oil separators (88, 90), each collecting chamber (28, 30) at least a separate oil separator (88, 90), a part throttle return line (100, 102) leading from an oil separator (90) downstream of the turbocharger (60, 62) to the intake line (52, 54), each oil separator (88, 90) opens a Vollastrückführleitung (92, 98) upstream of the turbocharger (60, 62) in the intake passage (52, 54), wherein at full load bleed gases each collecting chamber (28, 30) via the associated oil separator (88, 90) into the intake passage (52, 54) and the collecting chambers (28, 30) are fluidly connected, at least in part-load operation, and deaerating gas from at least two collecting chambers (28, 30) via the oil separator (90) of a collecting chamber (30) into the suction line (52, 54) flows.

2. Apparatus according to claim 1, characterized in that a plurality of rows of cylinders (12, 14) are provided and each row of cylinders (12, 14) has its own collection chamber (28, 30).

3. Apparatus according to claim 1 or 2, characterized in that the collecting chambers (28, 30) via the common crankcase (10) are fluidly connected to each other.

4. Device according to one of the preceding claims, characterized in that a plurality of turbochargers (60, 62) are provided which are each associated with individual or a group of cylinders (34, 36).

5. Apparatus according to claim 4, characterized in that each

Turbocharger (60, 62) an oil separator (88, 90) is associated.

6. Apparatus according to claim 4 or 5, characterized in that of the flow in the part-load operation oil separator (90) partial load return lines (100, 102) to the intake pipes (52, 54) downstream of the plurality of turbochargers (60, 62).

7. Device according to one of claims 4 to 6, characterized in that of the Ölabscheidem (88, 90) Vollastrückführleitungen (92, 98) to the intake pipes (52, 54) of the associated turbocharger (60, 62) lead.

8. Device according to one of the preceding claims, characterized in that a ventilation line is provided which leads to a collecting chamber (28) and via the connection of the collecting chambers (28, 30) is vented.

9. Apparatus according to claim 8, characterized in that the venting line in the Ölabscheidem (88), which does not work in part-load operation, opens.

10. Apparatus according to claim 8 or 9, characterized in that the

Vent line is the full return line (92).

11. Device according to one of the preceding claims, characterized in that check valves (94, 99) in the Vollastrückführleitungen (92, 98) are arranged.

12. The apparatus according to claim 10 or 11, characterized in that the

Check valve (94) is provided in the serving as a vent line Vollastrückführleitung (92) with a throttled bypass.

13. Device according to one of the preceding claims, characterized in that in the at least one or each partial load return line (100, 102) a variable throttle, in particular a PCV valve (104, 106), is provided.

14. Device according to one of the preceding claims, characterized in that the oil separator (88, 90) inertial, in particular cyclone, are. 15 Device according to one of the preceding claims, characterized in that the venting takes place zyhnderkopfseitig

16 Apparatus according to claim 15, characterized in that the collecting chambers (28, 30) in the valve covers (24, 26) are provided

17 A method for venting a Kurbeigehauses (10) of an internal combustion engine having a plurality of collecting chambers (28, 30) for Entluftungsgase, which own Olabscheider (88, 90) are assigned, characterized in that in part-load operation, the Entluftungsgase a collecting chamber (28) to a their unallocated oil separator (90) guided and vented over this, whereas in full load the Entluftungsgase the collecting chambers (28, 30) via their own, each associated oil separator (88, 90) are vented