DE102011102248B4 - Internal combustion engine - Google Patents

Abstract

Internal combustion engine (1) for a motor vehicle, with at least one combustion chamber (2) and an intake area (3) assigned to it, via which a fluid is supplied to the combustion chamber (2), and with at least one closed condensate collecting device arranged in the intake area (3) (8), which has a collecting chamber (9) into which condensate accumulating in the suction area (3) is forced by the influence of gravity, the collecting chamber (9) being formed by a cross-sectional area (10) of a line (5, 6) so that in the line (5, 6) - seen in cross section - a line region (11) and the collecting chamber (9) are present, or the line (5, 6) to form the collecting chamber (9) has a change in cross section (12) so that the Line (5, 6) - seen in cross section - has the collecting chamber (9) in addition to the line area (11) which is not changed in cross-section, characterized in that the collecting chamber (9) has a honeycomb structure (15) and from the line area (11) calibration (11) is at least partially separated by a perforated plate (17).

Description

The invention relates to an internal combustion engine, in particular for a motor vehicle, with at least one combustion chamber and an intake area assigned to it, via which a fluid is supplied to the combustion chamber, and with at least one closed condensate collecting device which is arranged in the intake area and has a collection chamber into which in condensate accumulating in the suction area is displaced by the influence of gravity, the collecting chamber being formed by a cross-sectional area of a line, so that in the line - seen in cross section - a line area and the collecting chamber are present, or the line to form the collecting chamber has a change in cross-section so that the line - seen in cross-section - has the collecting chamber in addition to the line area that is not changed in cross-section.

Internal combustion engines of the type mentioned are known from the prior art. The fluid is, in particular, air drawn in through the intake area, for example fresh air or mixed air containing fresh air. When such an internal combustion engine is operated at low ambient temperatures, in particular at temperatures around or below freezing point, condensate can occur in the intake area. The condensate is separated from the fluid. If there are temperatures in the intake area which are below the freezing point of the condensate, it will freeze. In this way, larger amounts of frozen condensate can collect in the suction area. The condensate usually consists mostly or entirely of water, so that the frozen condensate is in the form of ice.

If temperatures then occur in the suction area which are above freezing point, the frozen condensate melts again. The liquid condensate can now be entrained in larger quantities by the fluid and get into the combustion chamber of the internal combustion engine. This is particularly the case when the motor vehicle to which the internal combustion engine is assigned is parked in an environment in which the temperature is above the freezing point after driving at ambient temperatures that are well below the freezing point of the condensate. While the internal combustion engine is at a standstill, at least part of the frozen condensate can thaw and enter the combustion chamber when the internal combustion engine is then started. There is a risk that the condensate entering the combustion chamber in large quantities will damage the internal combustion engine or at least impair its operation.

For this reason, for example, in the DE 10 2009 006 966 A1 a method for regulating a charge air cooler is proposed in which the cooling capacity of the charge air cooler is set as a function of two threshold values of the charge air temperature of the charge air cooler during operation of the internal combustion engine. In this way, condensation in the intake area or ice formation can be at least partially prevented, so that the internal combustion engine is protected from damage by the condensate.

Such a control of the charge air cooler is on the one hand complex. On the other hand, due to the control, the entire nominal power of the internal combustion engine cannot be made available at every operating point. In addition, not every internal combustion engine has a charge air cooler.

Furthermore, the document is from the prior art DE 44 33 285 A1 known. This discloses an internal combustion engine with a crankcase in which a crankshaft is rotatably mounted, to which at least one connecting rod is articulated, which carries a piston that is movable in a cylinder tube covered by a cylinder head, gas exchange valves embedded in the cylinder head with an exhaust line and a combustion air line are connected. It is provided that the combustion air line has an oil trap device at the geodetically lowest point, which is designed as a trough.

An intake manifold for a multi-cylinder internal combustion engine is described in the publication JP 61-108 860 A1 described. The pamphlet JP H11-148 431 A in turn discloses an anti-icing structure for an intake throttle valve for an internal combustion engine and the document FR 2 862 576 A1 finally shows an intake duct for an internal combustion engine.

It is the object of the invention to provide an internal combustion engine which avoids the disadvantage mentioned at the beginning and in particular avoids damage to the internal combustion engine due to condensate. The measures used for this should be as efficient and inexpensive as possible.

According to the invention, this is achieved with an internal combustion engine having the features of claim 1. It is provided that the collecting chamber has a honeycomb structure and is at least partially separated from the line area by a perforated plate.

In principle, at least one closed condensate collecting device arranged in the suction area is provided. the The condensate collecting device is accordingly assigned to the suction area. It can be located at any point on or in the suction area, but is preferably provided in the line of the suction area. The closed condensate collecting device is to be understood as a condensate collecting device in which the condensate that has accumulated is not specifically discharged to the outside from the condensate collecting device, for example in the direction of a collecting container. Rather, no discharge of the condensate to the outside is provided. The condensate collecting device is accordingly a condensate collecting device which is closed to the outside. Fluid can only be supplied to this through the suction area. A discharge of the fluid and any condensate that may be present is provided exclusively through the intake area in the direction of the internal combustion engine. The internal combustion engine is, for example, a diesel internal combustion engine. The condensate collecting device can, however, also be provided in an Otto-cycle internal combustion engine. The fluid supplied to the combustion chamber is essentially gaseous. For example, the fluid is air or a fuel-air mixture. The air can be fresh air or, in particular in the case of exhaust gas recirculation, can have at least a portion of fresh air.

A further development of the invention provides that the suction area comprises at least one suction line and a collecting line as a line, the suction line being connected to the combustion chamber via an inlet and the collecting line being connected to the combustion chamber via the suction line. The fluid is fed to the combustion chamber via the suction line and the collecting line. Usually a suction line is assigned to each combustion chamber and a common collecting line is assigned to all combustion chambers. The individual suction lines open, on the one hand, into the respective combustion chamber and, on the other hand, into the common collecting line. The suction line can be connected to the combustion chamber via the inlet, which can also be referred to as an intake duct. At least one inlet valve, by means of which the amount of fluid introduced into the combustion chamber can be adjusted, is usually assigned to the inlet. The suction line and the collecting line are preferably designed to be rigid, that is to say they are each in the form of a tube. In this respect, the suction line is a suction pipe and the collecting line is a collecting pipe, which can also be referred to as a collector. It should be noted that the suction line is directly connected to the combustion chamber via the inlet. No further lines are therefore provided between the suction line and the combustion chamber.

A further development of the invention provides that the intake area has a charge air cooler and a charge air feed that opens into the charge air cooler. The internal combustion engine can therefore have a charger and the intercooler to increase performance. By means of the charger, which is designed as a turbocharger or compressor, for example, air that is sucked in can be compressed in order to increase the power density of the internal combustion engine. However, when the air is compressed, the temperature of the air increases, as a result of which the efficiency of the internal combustion engine drops. In order to achieve a particularly high increase in the performance of the internal combustion engine, the charge air cooler is therefore connected downstream of the charger. The compressed air therefore reaches the combustion chamber via the charge air cooler. The compressed air is cooled in the charge air cooler, i.e. brought to a lower temperature level, and then fed to the combustion chamber. On the side of the charge air cooler facing away from the combustion chamber, the charge air feed is provided which, for example, establishes a connection between the charger and the charge air cooler. The charge air supply is preferably also in the form of a line, preferably in the form of a pipeline.

A further development of the invention provides that the condensate collecting device is provided in the line, the charge air cooler or the charge air supply. In principle, the condensate collecting device can be arranged as desired in the suction area. However, it is preferably part of the line, the charge air cooler or the charge air feed, because in this way it can be arranged comparatively close to the combustion chamber. If there are several condensate collecting devices, these can be distributed as desired over the line, the charge air cooler and the charge air supply. For example, at least one condensate collecting device is provided in each case in the line, the charge air cooler and the charge air feed. Of course, it is also possible to have a common condensate collecting device in the areas mentioned. For example, the condensate collecting device can extend into the suction line in some areas and into the collecting line in some areas and in this respect be present as a common condensate collecting device of the two lines.

The invention provides that the condensate collecting device has a collecting chamber into which condensate accumulating in the suction area is forced by the influence of gravity. The collecting chamber serves to collect the condensate. The collecting chamber is not connected to the surroundings, so it is present as a collecting chamber that is closed to the outside. The collecting chamber is therefore only in flow connection with the suction area. The collecting chamber is arranged in the suction area in such a way that condensate accumulating in it is forced into it by the influence of gravity. This means that the collection chamber is usually in one lower area of the suction area, in particular an at least local low point of the suction area, is provided.

According to the invention it is provided that the collecting chamber is formed by a cross-sectional area of the line so that a line area and the collecting chamber are present in the suction pipe - seen in cross section - or that the line to form the collecting chamber has a change in cross section so that the line - in Cross-section seen - in addition to the line area that has not been changed in cross-section, it has the collecting chamber. The line is in particular in the form of the suction line or the collecting line. The collecting chamber can now be present directly in the cross-sectional area of the line, for example, viewed in cross section, it is subdivided in such a way that the line area and the collecting chamber are formed. Alternatively, the line can also have the change in cross section. This means that the line area and the collecting chamber continue to be present in the line when viewed in cross section. However, the line area is not or only slightly changed in cross-section compared to neighboring areas in which the collecting chamber is not present. The collecting chamber is thus essentially formed solely by the change in cross section of the line. This variant is more complex to manufacture, but the flow cross-section of the line in the area in which the collecting chamber is provided is not reduced. The pressure loss in the line is therefore comparatively low.

The invention provides that the collecting chamber has a honeycomb structure. In addition, it can optionally have a storable material, in particular a fiber structure or a porous foam, at least in some areas. The storable material or the honeycomb structure are used to collect and temporarily store the condensate. These are preferably designed in such a way that they are not damaged by freezing of the condensate. The storable material is present, for example, as a fiber structure or as a porous foam. The fiber structure is, for example, a fleece, a woven fabric, a knitted fabric or the like, consisting of several fibers. The honeycomb structure can be made of plastic or metal, for example. The individual honeycombs of the honeycomb structure are arranged in such a way that the condensate can flow into the honeycombs and is then held in them by the influence of gravity. The honeycombs are accordingly arranged essentially vertically, at least in relation to an expected arrangement of the internal combustion engine.

According to the invention it is provided that the collecting chamber is at least partially separated from the suction line area by a perforated plate. This is provided in particular to cover the honeycomb structure or the storable material. The collecting chamber is in flow connection with the suction line area through the perforated plate. Thus, condensate accumulating in the suction line area can easily pass through the perforated plate into the collecting chamber.

A further development of the invention provides that the collecting chamber forms an intermediate fluid store. This means that the condensate should only be temporarily present in the collecting chamber and in particular can get out of it again through evaporation or evaporation. The collecting chamber is preferably designed in such a way that the condensate can only get out of it again with a low throughput (mass or volume of the condensate per unit of time). The collecting chamber or the intermediate fluid store is accordingly provided for the slow or targeted delivery of the condensate to the fluid or in the direction of the combustion chamber, the throughput being less than or equal to a certain throughput at which no impairment or damage to the internal combustion engine occurs. It is therefore not provided that the condensate remains permanently in the collection chamber. Rather, it should be discharged in a targeted manner in the direction of the combustion chamber, this being provided with such a low throughput that the internal combustion engine is not damaged.

A further development of the invention provides that the condensate collecting device, in particular the intermediate fluid store, is heated at least in some areas by heat from the internal combustion engine. During the operation of the internal combustion engine, this heat is generated. The condensate collecting device should now be arranged in such a way that it can be heated by this heat. In this way, the condensate present in the condensate collecting device can be heated in a targeted manner so that - if it is in a frozen state - it is thawed. However, the heating can also be provided so that the condensate is heated above its boiling point so that it can be fed to the combustion chamber in a gaseous state.

• 1 eine schematische Ansicht einer Brennkammer einer Brennkraftmaschine mit einer in einem Ansaugbereich angeordneten Kondensatsammeleinrichtung,
• 2 einen Querschnitt durch eine Leitung, in welcher die Kondensatsammeleinrichtung vorliegt, in einer ersten Ausführungsform,
• 3 eine zweite Ausführungsform der Leitung mit der darin angeordneten Kondensatsammeleinrichtung,
• 4 einen Querschnitt durch eine nicht erfindungsgemäße erste Ausführungsform der Kondensatsammeleinrichtung,
• 5 einen Querschnitt und eine Draufsicht auf eine nicht erfindungsgemäße zweite Ausführungsform der Kondensatsammeleinrichtung, und
• 6 einen Querschnitt und eine Draufsicht auf eine erfindungsgemäße dritte Ausführungsform der Kondensatsammeleinrichtung.

The invention is explained in more detail below with reference to the exemplary embodiments shown in the drawing, without restricting the invention. Show it:

• 1 a schematic view of a combustion chamber of an internal combustion engine with a condensate collecting device arranged in an intake area,
• 2 a cross section through a line in which the condensate collecting device is present, in a first embodiment,
• 3 a second embodiment of the line with the condensate collecting device arranged therein,
• 4th a cross section through a first embodiment of the condensate collecting device, not according to the invention,
• 5 a cross section and a plan view of a second embodiment of the condensate collecting device, not according to the invention, and
• 6th a cross section and a plan view of a third embodiment of the condensate collecting device according to the invention.

the 1 shows a schematic view of an internal combustion engine 1 , which is present, for example, as a diesel internal combustion engine. The internal combustion engine 1 has at least one combustion chamber 2 , in which via a suction area 3 a fluid can be introduced. The suction area 3 in particular includes an inlet 4th , a suction line 5 and a manifold 6th . The suction line 5 lies as a suction pipe and the collecting line 6th as a collecting pipe in front of both lines 5 and 6th are therefore rigid. In the manifold 6th the fluid is provided, which is subsequently through the suction line 5 and the inlet 4th into the combustion chamber 2 can get. The inlet 4th is at least one inlet valve 7th assigned, by means of which the fluid is targeted in the combustion chamber 2 can be brought in. On that of the combustion chamber 2 remote side of the manifold 6th A charge air cooler (not shown here) and a charge air supply opening into this can be provided.

When the internal combustion engine is operated at low ambient temperatures, condensate can condense out of the fluid in the intake area. Lying in the suction area 3 Temperatures below the freezing point of the condensate, which can be the case in particular when using the charge air cooler, the condensate freezes in the intake area 3 . This allows a larger amount of frozen condensate to accumulate while driving. If the frozen condensate thaws again, it can suddenly enter the combustion chamber with a high throughput 2 reach. Under certain circumstances, this can damage the internal combustion engine 1 to lead. It is particularly dangerous when the internal combustion engine is operated at low temperatures so that - as described above - the condensate accumulates, the internal combustion engine is deactivated and a higher ambient temperature then occurs, so that the temperature in the intake area rises above the freezing point of the condensate. In this case, a large part of the frozen condensate or all of the condensate can thaw and suddenly enter the combustion chamber when the internal combustion engine is subsequently activated 2 arrive, which leads to malfunction of the internal combustion engine 1 or can lead to their damage.

Because of this, it is in the suction area 3 a closed condensate collector 8th arranged. This is only with the suction area 3 connected to the flow, so has no means to the in the condensate collecting device 8th evacuate condensate to the outside, for example in a collecting device. The condensate collecting device 8th is available as a closed condensate collecting device. The condensate collecting device 8th has a collection chamber 9 on which that in the suction area 3 accumulating condensate is pushed by the influence of gravity. Preferably the collection chamber is 9 with regard to an expected orientation of the internal combustion engine 1 arranged below, in particular in a local low point of the suction area 3 . In principle, the condensate collecting device 8th any in the suction area 3 be arranged. However, it is preferred in the lines 5 or 6th , the intercooler or the charge air supply.

the 2 shows a cross section through the manifold 6th . The representation is only to be understood as an example; in principle, what is described below can also apply to another line or another element of the suction area 3 be transferred, for example to the suction line 5 , the intercooler or the charge air supply. With the manifold shown here 6th becomes the collection chamber 9 of a cross-sectional area 10 the manifold 6th educated. Thus lie in the collecting line 6th both a management area 11 as well as the collection chamber 9 before. The management area 11 is the flow cross-section available to the fluid while it is in the collecting chamber 9 the resulting condensate collects.

the 3 shows a further variant of the manifold 6th . In contrast to the 2 The embodiment described here has the manifold 6th a change in cross-section 12th on. The collection chamber 9 lies in the change in cross-section 12th before that in the manifold 6th still the management area 11 is available, which is, however, compared to that based on the 2 shown is not changed in cross-section. In this way, the entire cross section of the collecting line is still available 6th for the flow through with the fluid available, whereby Pressure losses can be reduced. The one in the 3 Shown configuration of the manifold 6th is to be understood purely as an example. For example, it could be in the area of the change in cross-section 12th also have an oval cross-section and the collection chamber 9 in the over the circular cross-section of the line area 11 areas of the manifold beyond 6th are present.

the 4th shows a cross section through the condensate collecting device 8th , which is present in a first embodiment not according to the invention. It becomes clear that in the collection chamber 9 the condensate collecting device 8th a storable material 13th is arranged. This can, for example, have a fiber structure or be a porous foam. The fiber structure is to be understood in particular as a fleece, a woven fabric, a knitted fabric or the like, which is designed to absorb and store or temporarily store the condensate. The material 13th can of a cover 14th be covered, which has openings, so that the condensate in the material 13th can get. The cover 14th however, it is purely optional.

the 5 shows a second embodiment of the condensate collecting device, not according to the invention, with a cross section at the top and a plan view of the condensate collecting device at the bottom 8th is shown. In this embodiment it is in the collecting chamber 9 a honeycomb structure 15th provided, which is formed for example by a honeycomb lattice. The honeycomb structure 15th exhibits numerous honeycombs 16 , of which only a few are identified as examples. The honeycombs 16 the honeycomb structure 15th can, but do not have to be flow-separated from one another. This means that in the honeycomb 16 present condensate not in an adjacent honeycomb 16 can get.

the 6th shows a third embodiment of the condensate collecting device according to the invention 8th Again, a cross section is shown above and a plan view is shown below. In the top view it becomes clear that the collection chamber 9 with a perforated sheet 17th is covered, so that in the suction area 3 existing condensate only through holes 18th of the perforated sheet 17th , of which only a few are marked, into the collecting chamber 9 can get in. Below the perforated sheet 17th is based on the 5 honeycomb structure shown 15th before. However, it can also only be braces 19th to support the perforated plate 17th are present.

The collection chamber described above 9 is available as an intermediate fluid store. This means that the condensate is from the suction area 3 into the collection chamber 9 and is only cached there. The condensate is therefore returned to the suction area over a certain period of time 3 or delivered to the fluid flowing through it. However, this only takes place with a low throughput, so that no larger amount of the condensate which is again from the collection chamber 9 got out, suddenly into the combustion chamber 2 is introduced.

With the collection chamber 9 or the condensate collecting device 8th is accordingly caused that even if a larger amount of condensate is present in the suction area 3 an introduction of this condensate into the combustion chamber 2 always takes place only with a low throughput or mass flow. This will damage the internal combustion engine 1 or an impairment of their operations is avoided as far as possible. It is particularly advantageous if the condensate collecting device 8th is arranged such that it is at least partially from the heat of the internal combustion engine 1 is heatable. The heat of the internal combustion engine 1 can, for example, via thermal conduction of the lines 5 and 6th or via convection to the condensate collector 8th reach. For this purpose, the condensate collection device 8th in the area of the combustion chamber 2 arranged, for example in the 1 is shown.

List of reference symbols

1

Internal combustion engine

2

Combustion chamber

3

Suction area

4th

inlet

5

Suction line

6th

Manifold

7th

Inlet valve

8th

Condensate collecting device

9

Collection chamber

10

Cross-sectional area

11th

Management area

12th

Change in cross-section

13th

material

14th

cover

15th

Honeycomb structure

16

Honeycomb

17th

Perforated sheet

18th

Holes

19th

Bracing

Claims (7)

Internal combustion engine (1) for a motor vehicle, with at least one combustion chamber (2) and an intake area (3) assigned to it, via which a fluid is supplied to the combustion chamber (2), and with at least one closed condensate collecting device arranged in the intake area (3) (8), which has a collecting chamber (9) into which condensate accumulating in the suction area (3) is forced by the influence of gravity, the collecting chamber (9) being formed by a cross-sectional area (10) of a line (5, 6) so that in the line (5, 6) - seen in cross section - a line area (11) and the collecting chamber (9) are present, or the line (5, 6) to form the collecting chamber (9) has a change in cross section (12) so that the Line (5, 6) - seen in cross section - has the collecting chamber (9) in addition to the line area (11) which is not changed in cross-section, characterized in that the collecting chamber (9) has a honeycomb structure (15) and from the line area (11) rich (11) is at least partially separated by a perforated plate (17). Internal combustion engine after Claim 1 , characterized in that the suction area (3) comprises as a line (5, 6) at least one suction line (5) and a collecting line (6), the suction line (5) via an inlet (4) and the collecting line (6) via the suction line (5) is connected to the combustion chamber (2). Internal combustion engine according to one of the preceding claims, characterized in that the intake area (3) has a charge air cooler and a charge air feed opening into the charge air cooler. Internal combustion engine according to one of the preceding claims, characterized in that the condensate collecting device (8) is provided in the line (5, 6), in the charge air cooler or in the charge air feed. Internal combustion engine according to one of the preceding claims, characterized in that the collecting chamber (9) has a storable material (13) at least in some areas. Internal combustion engine according to one of the preceding claims, characterized in that the collecting chamber (9) forms an intermediate fluid store. Internal combustion engine according to one of the preceding claims, characterized in that the condensate collecting device (8) is at least partially heated by heat from the internal combustion engine (1).

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