EP2935827A1

EP2935827A1 - Intake pipe for an internal combustion engine

Info

Publication number: EP2935827A1
Application number: EP13753616.5A
Authority: EP
Inventors: Volker Cornelius
Original assignee: Volkswagen AG
Current assignee: Volkswagen AG
Priority date: 2012-09-01
Filing date: 2013-08-23
Publication date: 2015-10-28
Also published as: WO2014033053A1; DE102012017391A1

Abstract

The invention relates to an intake pipe (20) for an internal combustion engine, comprising a housing, which forms an inlet duct (28) and one or more outlet ducts (46) connected to the inlet duct (28) in a fluid-conducting manner, wherein each outlet duct (46) is designed for a fluid-conducting connection to a respective inlet duct of the internal combustion engine. The intake pipe (20) is characterized by the arrangement of a compressor inside the housing, which compressor is driven by means of an electric motor (48).

Description

description

Suction tube for an internal combustion engine

The invention relates to a suction pipe for an internal combustion engine of an internal combustion engine and to such a suction pipe and an internal combustion engine having

Internal combustion engine.

Internal combustion engines, which are used, for example, for driving motor vehicles, are often charged to increase performance. This will be the combustion chambers of the

Internal combustion engine supplied fresh gas compressed by a compressor. As a result, the amount of fresh gas which can be introduced into the combustion chambers and thus also the amount of fuel combustible there as part of a working cycle can be increased.

The charging of internal combustion engines by means of exhaust gas turbochargers, which in addition to a compressor integrated into the fresh gas train, also has a turbine integrated in an exhaust gas line of the internal combustion engine, is widespread. The turbine gets through this

driven exhaust gas, wherein the rotation of the turbine is transmitted by means of a shaft to the compressor. An important advantage of exhaust gas turbochargers is that the energy required for the compression of the fresh gas recovered from the exhaust gas and thus - in contrast to likewise known mechanical superchargers - no net power of

Internal combustion engine is branched off.

A principal disadvantage of exhaust gas turbochargers is that the compressor power is directly dependent on the exhaust gas flow. With only a small exhaust gas flow thus only a small compressor power is achieved. This can be noticeable in a delayed response during operation of the internal combustion engine if, after operation with low load and low rotational speeds of the internal combustion engine, in particular out of idling, the load requirement is increased. This high load requirement must first be converted into a correspondingly increased exhaust gas flow, which then only leads to increased compressor performance. This delayed response is often referred to as "turbo lag".

There are a variety of ways to reduce turbo lag. On the one hand, the turbine of the exhaust gas turbocharger can be designed with a variable inlet geometry (so-called VTG exhaust gas turbocharger). In this case, the turbine has adjustable guide vanes at the turbine inlet, through which the flow cross section is variable. At a

comparatively low exhaust gas flow can be reduced by the guide vanes of the flow cross-section, whereby the flow velocity of the exhaust gas flowing into the turbine is increased. Another way to reduce the turbo lag is to combine two or even more turbocharger in an internal combustion engine. In doing so, e.g. two exhaust gas turbochargers connected in parallel, which cause the compression of the fresh gas together over the entire operating range of the internal combustion engine. The turbines and compressor impellers of the two turbochargers can be made smaller than the turbine and the compressor impeller of a single exhaust gas turbocharger, which must enforce the entire exhaust and fresh gas flow (at full load) alone. Smaller turbines and smaller compressor wheels have a lower inertia, which accelerates and thus improves the response. It is also known to connect a small and a large turbocharger in series, with the smaller

Exhaust gas turbocharger for a good response and the large exhaust gas turbocharger for a sufficient flow rate of fresh gas and fresh gas at full load ensures. By-passes for the turbines and compressor impellers of the two exhaust gas turbochargers can be bypassed in certain operating ranges of the internal combustion engine, i. be deactivated.

Also known is the charging of an internal combustion engine by means of an electrically driven compressor, wherein is provided in internal combustion engines for motor vehicles, either the compressor, an exhaust gas turbocharger at low exhaust gas mass flows

supportive of driving an electric motor or a separate electric

to integrate driven compressor in addition to an exhaust gas turbocharger in the fresh gas line of the internal combustion engine. In this case, the electrically driven compressor is also only as supportive additional charge at a low compressor power of

Exhaust gas turbocharger used. The mission is then limited to a period of only up to one second. By the electrically driven compressor in particular a pre-acceleration of the fresh gas in the fresh gas line should be achieved, whereby a run-up of the compressor of the exhaust gas turbocharger is supported. Advantages of an electrically driven compressor are the structurally simple design by dispensing with a turbine exposed to the hot exhaust gas flow as well as the principal

Independence of the compressor operation of the exhaust gas flow generated by the internal combustion engine or the rotational speed of the internal combustion engine. However, a problem is the short term very high electrical power that receives the electrically driven compressor in operation and can be supplied via the regularly operated with 12 V electrical system of the motor vehicle only with considerable design overhead. An electrically driven compressor thus requires an additional electrical power supply higher operating voltage. The associated additional effort has meant that electrically driven compressors are not yet used in mass production.

An internal combustion engine in which an exhaust gas turbocharger is combined with an electrically driven compressor is known, for example, from DE 102 15 779 A1. There is provided that the electrically driven compressor together with an electric throttle, a charge air cooler, an electric coolant pump and a

Intake manifold module in a common, referred to as "air module" housing

is summarized.

The document US 2005/005920 A1 describes an internal combustion engine in whose air supply system an electrically driven compressor is arranged. The electrically driven compressor has its own housing. The compressed air from the compressor is supplied to the internal combustion engine of the internal combustion engine via a connected separate fluid line.

Based on this prior art, the present invention seeks to improve a supercharged by means of an electrically driven compressor internal combustion engine, in particular with regard to the required space.

This object is achieved by an internal combustion engine according to independent claim 8. An inventive intake manifold used in this invention intake manifold is the subject of independent claim 1. Advantageous embodiments of the intake manifold according to the invention and the internal combustion engine according to the invention are the subject of the respective dependent claims and will be apparent from the

following description of the invention:

The invention is based on the idea of keeping the installation space for the integration of an electrically driven compressor as small as possible by integrating or accommodating the compressor in the intake manifold of the internal combustion engine.

According to the invention, a suction pipe is understood to be the portion of the fresh gas train directly adjoining the internal combustion engine, which divides the flow of the fresh gas into a plurality of partial flows (in particular the number of cylinders formed in the internal combustion engine) and supplies them to the internal combustion engine. Therefore, an intake manifold (typically) has one intake passage and a plurality of exhaust passages, the exhaust passages being in fluid communication with intake passages of the internal combustion engine. Regularly closes upstream of the suction pipe a (in a section of a Intercooler integrated) throttle valve (gasoline engines) or parking flap (diesel engines) on.

An inventive intake manifold for an internal combustion engine accordingly has a housing which forms (at least) one intake passage and one or more exhaust passages fluidly connected to the intake passage, wherein the exhaust passages are provided for a fluid-conducting connection, each with an intake passage of the internal combustion engine, wherein within the Housing also a means of (at least) an electric motor driven compressor (at least its impeller) is arranged. In this case, the compressor is preferably designed as a flow compressor and in particular as a radial compressor.

An internal combustion engine according to the invention comprises at least one internal combustion engine and a suction pipe according to the invention which is fluid-conductively connected to the internal combustion engine.

In a preferred embodiment, in the housing of the suction tube is still a

Intercooler integrated. Such intercoolers are required in supercharged internal combustion engines, since the compression of the fresh gas is associated with a temperature increase, which would lead to a loss of filling and is therefore reversed by active cooling. Due to the inventively preferred integration of the charge air cooler in the intake manifold, a particularly compact unit is created, which provides the required space for the

Internal combustion engine keeps low. In addition, the charge air cooler can be positioned in the flow direction of the fresh gas behind the electrically driven compressor, so that it can cool the fresh gas compressed by this and thus heated. In other words, the intercooler may preferably downstream of the means of the electric motor driven

Be arranged compressor in the suction pipe.

Due to the additional integration of the preferably liquid-cooled charge air cooler in the intake manifold, the liquid cooling of the charge air cooler can be used in addition to cooling the electrically driven compressor and in particular of the electric motor and / or power electronics in an advantageous manner. A separate cooling system for the electrically driven compressor can be dispensed with.

The liquid cooling for the intercooler and (preferably) the electrically driven compressor can preferably also be the same liquid cooling, which is also used for cooling the internal combustion engine. Such sharing of a single cooling system is particularly due to the proximity of intercooler, electrically driven compressor and internal combustion engine due to the inventive design of the intake manifold allows.

In a further preferred embodiment of the suction pipe according to the invention can be provided that the inlet channel is divided into at least one section, whereby at least two flow paths, in particular at least partially substantially parallel extending for the flowing through the suction pipe (fresh) gas are formed, of which first to the compressor (and from there to the exhaust ducts) and a second bypassing the compressor to the exhaust ducts.

In this case, it may further be preferred that the first and / or the second

Flow path is closed by means of a control flap. As a result, there is the possibility of the electrically driven compressor only temporarily, especially in certain

Operating conditions of the internal combustion engine to flow from the fresh gas and take it into operation. In this case, a startup is preferably in particular when the internal combustion engine produces only a small exhaust gas flow through a low load request and thereby preferably in addition to the electric

driven compressor provided additional compressor of an exhaust gas turbocharger only a small compressor power generated. By closing the second, the electric compressor bypassing the flow path, the entire fresh gas flow can then be performed on the electrically driven compressor. On the other hand, if, as a result of a sufficiently large exhaust gas flow of the compressor of the exhaust gas turbocharger produces sufficient compressor power, the first, leading to the electrically driven compressor flow path can be closed. This will prevent the electric

driven compressor is flown by the fresh gas. This is particularly advantageous when the intercooler - as preferably provided - is integrated in the flow direction behind the electrically driven compressor in the intake manifold. It is then prevented that the still relatively hot fresh gas flowing through the exhaust gas turbocharger as a result of the compression by the exhaust gas turbocharger flows through the then electrically driven compressor which is then deactivated. Its temperature load can thus be kept low.

In particular, this embodiment makes it possible to form the electrically driven compressor and in particular its impeller advantageously made of plastic, which on the one hand keeps the manufacturing costs and on the other hand, the mass low.

If control valves are provided for closing off both flow paths as required, it can preferably be provided that they are connected to one another such that an opening of one control flap leads to a closing of the other control flap. This can be achieved in a structurally simple manner, for example, characterized in that both control valves are actuated by means of a common shaft. On the other hand, it is also possible to connect the two control valves accordingly control technology.

The invention is described below with reference to an illustrated in the drawings

Embodiment explained in more detail. In the drawings shows:

1 shows an embodiment of an internal combustion engine according to the invention in a perspective view;

Fig. 2: the suction pipe of the internal combustion engine of Fig. 1 in a perspective

Presentation;

Fig. 3: a horizontal section through the suction tube of Fig. 2; and

4 shows a horizontal section through a suction tube for use with the

Internal combustion engine according to FIG. 1 in a second embodiment.

The internal combustion engine shown in FIG. 1 comprises an internal combustion engine which operates in a known manner according to the diesel principle. Within a cylinder crankcase 10 of the internal combustion engine four cylinders are formed, in which pistons are mounted longitudinally movable. The pistons are each connected to one end of a connecting rod whose other end is connected to a crankshaft. The upper end of the cylinder-crankcase 10 is covered by a cylinder head 12, in which at least one inlet and one outlet channel are formed for each cylinder. Within the inlet and

Exhaust ports are arranged inlet and exhaust valves, which are controlled by a camshaft in response to a rotational angle position of the crankshaft. The fuel for operating the internal combustion engine is introduced directly into the combustion chambers formed between the cylinder head and the pistons of the respective cylinders. This is done via a common pressure accumulator, the so-called "common rail" 14. In the combustion chambers of the fuel with fresh gas, which is by means of an air filter (not visible) pre-cleaned ambient air and optionally a proportion of recirculated exhaust gas, burned.

The fresh gas is supplied to the internal combustion engine via a fresh gas line which, in addition to the air filter, also comprises a compressor of an exhaust-gas turbocharger (not visible). The compressor of the exhaust gas turbocharger of the internal combustion engine is arranged upstream of the by means of an electric motor (48) driven compressor in the fresh gas line. A turbine of the exhaust gas turbocharger is integrated into an exhaust line, via which the generated in the combustion chambers Exhaust gas is removed from the internal combustion engine. After compression in the compressor of the exhaust gas turbocharger fresh gas flows through a charge air pipe 16 and a parking flap 18 in a suction pipe 20, which is part of the Frischgasstrangs of the internal combustion engine. The

Suction pipe according to the invention forms in particular the part of the fresh gas line, the end of which is connected directly to the internal combustion engine.

The suction tube 20 comprises a multi-part housing with an inlet part 22, a

Charge air cooler part 24 and an outlet part 26, which are fluid-conductively connected to each other. The inlet part 22 is designed as a cast component made of aluminum and forms an inlet channel 28, via which the suction pipe 20, the fresh gas, coming from the compressor of the exhaust gas turbocharger, is supplied. The inner volume of the inlet part 22 is divided in a section by a partition wall 30, whereby two flow paths are formed, of which a first (32) to the impeller 34 of a radial compressor, electrically

driven compressor leads. In this case, the impeller 34, which is arranged in a connected to the inlet part 22 compressor housing 36, flows axially from the fresh gas, while an outflow takes place in the radial direction. After flowing through the electrically driven compressor, the compressed fresh gas flows into the second flow path 40, which otherwise, bypassing the electrically driven compressor, connects the inlet channel 28 of the inlet part 22 to a charge air cooler 42 arranged in the charge air cooler part 24. The first flow path 32 and the second flow path 40 of the inlet part 22 are substantially parallel to each other. Furthermore, the first run

Flow path 32 and the second flow path 40 substantially perpendicular to

Flow direction through the intercooler 42. During operation of the driven by the electric motor 48 compressor, the first flow path 32 is at least partially flowed through by the compressor compressed fresh gas in the opposite flow direction.

The intercooler 42 and the charge air cooler part 24 of the housing of the intake manifold 20 are designed in sheet metal construction. In the charge air cooler 42, the fresh gas is cooled, wherein the cooling capacity of a liquid-cooled heat exchanger comprehensive intercooler 42 is controllable. On the intercooler 42, more precisely on the outside of the charge air cooler part 24, the compressor housing 36 of the electrically driven compressor is arranged directly or directly, received or attached.

The fresh gas leaving the intercooler 42 flows into the outlet part 26 of the housing of the intake manifold 20, which is also made of cast aluminum and whose internal volume is subdivided by three partition walls 44 into four exhaust ducts 46 which are fluid-conductively connected to the inlet duct or ducts of a cylinder of the internal combustion engine are. The compressor integrated into the intake manifold 20 is driven by means of an electric motor 48, which is controlled by an engine control of the internal combustion engine. This can advantageously be provided according to the invention only if, as a result of too low an exhaust gas flow of the compressor of the exhaust gas turbocharger too little compressor power generated and thus in particular when the engine is operated with low load and low speeds and in particular at idle. It is then provided to lead the entire fresh gas flow over the electrically driven compressor as far as possible by closing the second flow path 40, which bypasses the electrically driven compressor, by means of a control flap 50. Such a control flap 50 is provided in the two embodiments of a suction tube 20 according to the invention shown in FIGS. 3 and 4. The control flap 50 also prevents the fresh gas compressed by the electrically driven compressor from flowing back into the charge air pipe 16 through the second flow path 40.

In the embodiment according to FIG. 3, a further control flap 52 is provided, by means of which the first, leading to the electrically driven compressor flow path 32 can be closed if necessary. This occurs in particular when, as a consequence of a sufficiently large exhaust gas flow, the compressor of the exhaust gas turbocharger generates sufficient compressor power. By closing the first flow path 32 of the then deactivated electrically driven compressor is not flown by the heated by the compression of the exhaust gas turbocharger fresh gas, whereby the temperature load can be kept low. This makes it possible to form the electric driven compressor, but at least its impeller made of plastic instead of metal (especially aluminum or steel), which not only keeps its manufacturing cost but also its mass low. A small mass is associated with a low inertia, which in turn can lead to a relatively low required drive power and thus to a comparatively small electric motor 48.

In the embodiment of a suction tube according to the invention according to FIG. 3, both control valves 50, 52 are actuated by means of a common shaft 38 which is driven, for example, by an electric motor (not visible). The control valves 50, 52 would therefore be electrically controlled. Alternatively, however, it could also be provided that the control valves 50, 52 are otherwise connected, e.g. to control hydraulically or pneumatically. In yet another alternative embodiment, it is provided that the control valves 50, 52 as a result of

prevailing pressure differences automatically occupy the required positions.

Between the two control valves 50, 52, an angle of approximately 90 ° is provided, whereby it is achieved that opening the one flow path to a simultaneous closing of other flow path leads. If the one flow path is completely closed with the associated control flap, the corresponding other flow path is opened as far as possible.

In the embodiment according to FIG. 4, a control flap which closes the first flow path is not provided. Nevertheless, even there the temperature load of the electrically driven compressor can be kept within limits, since the flow cross-section of the first flow path is dimensioned much smaller than that of the second flow path. In conjunction with the back pressure that the deactivated compressor in the first

Produced flow path, this causes the fresh gas flows to a large extent on the second flow path in the intercooler. In this embodiment, an embodiment of the electrically driven compressor and in particular its impeller made of a metal (in particular (an) aluminum (alloy) or steel) is preferred. Alternatively, an embodiment of plastic is possible.

LIST OF REFERENCE NUMBERS

Cylinder crank case

cylinder head

Common rail

Charge air pipe

parking device

suction tube

inlet portion

Intercooler part

outlet

inlet channel

partition wall

first flow path

Wheel

compressor housing

wave

second flow path

Intercooler

partition wall

exhaust port

electric motor

control flap

Claims

claims

A suction tube (20) for an internal combustion engine having a housing having an inlet channel (28) and one or more fluidly connected to the inlet channel (28)

Auslasskanäle (46) is formed, wherein the outlet channels (46) for a fluid-conducting

Connection are provided with in each case one inlet channel of the internal combustion engine, characterized by the arrangement of one by means of an electric motor (48)

driven compressor within the housing.

2. suction tube (20) according to claim 1, characterized by a disposed within the housing between the inlet channel (28) and the outlet channels (46)

Intercooler (42).

3. intake manifold (20) according to claim 2, characterized in that the charge air cooler (42) comprises a liquid-cooled heat exchanger and that cooling of the electrically driven compressor is performed by the cooling liquid of the heat exchanger.

4. intake manifold (20) according to claim 1, characterized in that the charge air cooler (42) is arranged downstream of the means of the electric motor driven compressor in the suction pipe (20).

Suction tube (20) according to claim 1, characterized in that the inlet channel (28) is subdivided into at least one section, whereby at least two flow paths (32, 40) are formed for gas flowing through the suction tube (20), one of which leading first (32) to the compressor and a second (40), bypassing the compressor to the outlet channels (46).

6. suction tube (20) according to claim 5, characterized in that the first

Flow path (32) and the second flow path (40) of the inlet part (22) in

Essentially parallel to each other.

7. Suction tube (20) according to claim 5, characterized in that the first

Flow path (32) and the second flow path (40) extend substantially perpendicular to the flow direction through a charge air cooler (42).

8. suction tube (20) according to claim 5, characterized in that the first flow path (32) by means of a control flap (52) is closable.

9. suction tube (20) according to claim 5, characterized in that the second

Flow path (40) by means of a control flap (50) is closable.

10. Suction tube (20) according to claim 8, characterized in that the second

Flow path (40) by means of a control flap (50) is closable and that the

Control flaps (50, 52) are interconnected such that an opening of the one leads to a closing of the other.

1, suction tube (20) according to claim 10, characterized in that the control valves (50, 52) by means of a common shaft (38) are actuated.

12. Suction tube (20) according to claim 2, characterized in that the

Compressor housing (36) of the electrically driven compressor is arranged directly on the intercooler (42).

13. Internal combustion engine with an internal combustion engine and a suction pipe (20) according to

Claim 1.

14. Internal combustion engine according to claim 13, characterized by at least one

Exhaust gas turbocharger whose compressor upstream of the by means of an electric motor (48) driven compressor is arranged in the fresh gas line.