WO2018077370A1

WO2018077370A1 - Internal combustion engine, in particular for a motor vehicle

Info

Publication number: WO2018077370A1
Application number: PCT/EP2016/001765
Authority: WO
Inventors: Daniel Rogg; Bernd Regenthal
Original assignee: Daimler Ag
Priority date: 2016-10-25
Filing date: 2016-10-25
Publication date: 2018-05-03

Abstract

An internal combustion engine (10) having an intake tract (16), through which air can flow and which serves for conducting air to at least one combustion chamber (14), having at least one sensor (26), which is arranged in the intake tract (16) and which serves for detecting a pressure, having at least one housing element (12), which has at least one receiving space for at least partially receiving at least one shaft, and having at least one ventilation line (30), which is fluidically connected to the intake tract (16) and to the receiving space and by means of which a gas can be introduced from the receiving space into the intake tract (16), having a diagnostic device (34) which comprises at least one casing line (36) surrounding at least one length region of the ventilation line (30), comprises at least one diagnostic chamber (38) arranged between the casing line (36) and the length region, comprises a diagnostic line (40) fluidically connected to the diagnostic chamber (38) and to the intake tract (16), and comprises the sensor (26), by means of which at least one leakage, arranged in the length region, of the ventilation line (30) can be detected.

Description

Internal combustion engine, in particular for a motor vehicle

The invention relates to an internal combustion engine, in particular for a

Motor vehicle, according to the preamble of claim 1.

Such an internal combustion engine, in particular for a motor vehicle such as a passenger car, is already known from DE 10 201 1 086 361 A1 as known. The internal combustion engine has one of air

permeable intake tract, by means of which the intake air flowing through the air is guided to at least one combustion chamber of the internal combustion engine. Furthermore, the internal combustion engine has at least one sensor arranged in the intake tract, by means of which a pressure in the intake tract can be detected. In other words, the sensor is designed as a pressure sensor, by means of which a pressure prevailing in the intake tract is detected. This pressure is effected in particular by the air flowing through the intake tract or taken up in the intake tract.

The internal combustion engine further comprises at least one housing element, which has at least one receiving space for at least partially receiving at least one shaft of the internal combustion engine. The shaft is, for example, an output shaft via which the

Internal combustion engine provides torques for driving the motor vehicle. The output shaft is for example a crankshaft, in which case the

Internal combustion engine is designed as a reciprocating internal combustion engine. The housing element may thus be a crankcase in which the crankshaft is at least partially received. In this case, the shaft is rotatably supported, for example, on the housing element about an axis of rotation relative to the housing element. In addition, the internal combustion engine comprises at least one

Vent line, which is fluidly connected on the one hand with the intake and on the other hand with the receiving space. By means of the vent line, a gas from the receiving space can be discharged and introduced into the intake tract. The vent line may be in particular part of a so-called crankcase ventilation, by means of which gas in the form of so-called blow-by or blow-by gas from the

Recording space and thus the crankcase dissipated and introduced into the intake tract. In the case of the crankcase, the receiving space is for example a so-called crankcase of the crankcase.

By discharging the gas from the receiving space may be an excessive

Pressure increase in the receiving space and thus be avoided in the housing element. In the gas, in particular the blow-by, components such as unburned hydrocarbons and lubricant components may be included. In order to

prevent these components from easily reaching the environment or environment, the components are introduced together with the gas in the intake tract. The air flowing through the intake tract can take along the gas introduced into the intake tract and thus the constituents contained in the gas and transport it into the combustion chamber designed, for example, as a cylinder. The constituents or the gas can thus take part in a combustion process in the combustion chamber and then flow through an exhaust tract and in particular an exhaust gas aftertreatment device of the internal combustion engine arranged in the exhaust tract.

Furthermore, DE 103 20 054 A1 discloses a method for operating an internal combustion engine, with a suction pipe and a ventilation channel of a vent, in particular a tank or crankcase ventilation, the suction pipe of the

Internal combustion engine is supplied. It is provided that at least one pressure difference between on the one hand an intake manifold pressure or ambient pressure or an ambient pressure and on the other hand, a pressure in the vent channel is determined and that a fault of the vent is diagnosed depending on the at least one pressure difference.

Object of the present invention is to develop an internal combustion engine of the type mentioned in such a way that a particularly simple

Diagnosis and thus detection of leaks of the vent line can be realized. This object is achieved by an internal combustion engine having the features of patent claim 1. Advantageous embodiments with appropriate

Further developments of the invention are specified in the remaining claims.

To further develop an internal combustion engine specified in the preamble of claim 1 type such that a particularly simple and in particular cost-effective diagnosis and thus detection of leaks

Vent line can be realized according to the invention a diagnostic device is provided, which at least one at least a length range of

Vent line surrounding surrounding duct. The diagnostic device further comprises at least one arranged between the Hüllleitung and the length range diagnostic space and a diagnostic line, which is connected on the one hand to the diagnostic room and on the other hand to the intake system fluidly. The diagnostic device further comprises the sensor, by means of which at least one arranged in the length range leakage of the vent line can be detected.

The sheath line surrounds the vent line completely, for example, in the circumferential direction of the vent line, wherein it is further preferably provided that the envelope line at least partially, in particular predominantly or even completely surrounds the vent line with respect to the longitudinal extent of the vent line. The envelope surrounds the vent line in such a way that the envelope is spaced from the vent line, so that between the vent line of the envelope of the

Diagnostic room is formed. The diagnostic room is a control volume or is used as a control volume. As a rule, or normal case, in which the vent line in the length range has no leakage, prevails in the control volume

(Diagnosis) the same pressure as in the intake tract, since the diagnostic room on the

Diagnostic line is fluidly connected to the intake. The prevailing in the intake pressure, which is detected by the sensor or is detectable, for example, is a so-called intake manifold pressure, since the sensor, for example, arranged in a suction arranged in the intake manifold and the diagnostic line is fluidly connected to the suction pipe.

If there is a leakage of the vent line in the length range, so that, for example, at least part of the gas flowing through the vent line and discharged from the receiving space gas from the vent line and can flow into the diagnostic room, then changes in the control volume

(Diagnostic space) prevailing pressure or by this leakage of pressure prevailing in the diagnostic space pressure is affected. Due to the fluidic connection of the diagnostic room The intake pressure also changes, at least in the short term, the pressure prevailing in the intake tract or the pressure prevailing in the intake tract is adversely affected by the leakage. This change or impairment of the pressure can be detected by means of the example designed as a Saugrohrdrucksensor sensor. Thus, it is possible to detect leaks of the vent line by means of the already existing and designed as a pressure sensor sensor and thus diagnose, so that no additional sensors are required for the diagnosis of the vent line. As a result, the space requirement, the cost, the number of parts and the weight for realizing the diagnosis of the vent line can be kept particularly low while realizing a venting of the receiving space, wherein the discharge of the gas from the receiving space is referred to as vent.

In particular, it is possible by means of the diagnostic device, the ventilation of the

To monitor recording space as part of an on-board diagnostic (OBD - on-board diagnostics), without the need for additional pressure sensors is required. Furthermore, changes may be made to the example as a crankcase

Housing element can be avoided.

The idea underlying the invention is to provide a double function to the already existing sensor arranged in the intake tract. First, the sensor is used to detect the pressure prevailing in the intake manifold. On the other hand, the sensor is used to detect any leakage of the vent line.

The diagnostic device can be used particularly advantageously if the

Vent line is designed as an external line and in particular as an external full load vent path. In the case of the internal combustion engine according to the invention, a particularly simple diagnosis of the external line or the external full-load ventilation path is possible. Under such an external line is to be understood that the vent line or the venting of the receiving space is not in the

Housing element is structurally integrated, but the vent or vent line extends, for example, outside of the housing, in particular outside the

Receiving space.

Further advantages, features and details of the invention will become apparent from the following description of a preferred embodiment and from the drawing. The above features mentioned in the description and Combinations of features as well as features and combinations of features mentioned below in the description of the figures and / or alone in the single figure are not only in the respectively specified combination, but also in others

Combinations or unique use, without departing from the scope of the invention.

The drawing shows in the single FIGURE is a schematic representation of a

Internal combustion engine for a motor vehicle, with a vent line for venting a crankcase of the internal combustion engine, and with a

Diagnostic device for diagnosis of the vent line.

The single FIGURE shows a schematic representation of a

Internal combustion engine 10 for a motor vehicle, in particular a

Passenger cars. The internal combustion engine 10 comprises a housing element 12, which in the present case is designed as a cylinder crankcase. The

Cylinder crankcase has a plurality of combustion chambers in the form of cylinders 14. In the present case, the internal combustion engine 10 comprises exactly four cylinders 14, which are arranged in series. Thus, the internal combustion engine 10 is formed as a four-cylinder in-line engine. The internal combustion engine 10 further comprises an output shaft, not visible in the figure, which is rotatably mounted on the cylinder crankcase (housing element 12) about an axis of rotation relative to the housing element 12. In the respective cylinder 14, a piston, which can not be seen in the figure, is received in a translationally movable manner, with the respective piston being articulated to the crankshaft via a connecting rod. As a result of this articulated coupling, the translational movements of the respective piston can be converted into a rotational movement of the crankshaft about its axis of rotation. Thus, the

Internal combustion engine 10 via the output shaft (crankshaft) provide torques for driving the motor vehicle.

The internal combustion engine 10 comprises an air intake air intake tract 16, by means of which the intake air 16 flowing through the air to the cylinders 14 is guided. In the intake manifold 16, a suction pipe 18 is arranged, which - as in

Below will be explained - acts as an air distributor, in particular charge air manifold, and the air flowing through the intake 16 air distributed to the cylinder 14. In the intake duct 16, an air filter 20 is further arranged, by means of which the air is filtered. The cylinders 14 thus receive the air flowing through the intake tract 16 as well as fuel, in particular liquid fuel. From this supply results in a respective fuel-air mixture in the cylinder 14. This fuel-air mixture is burned, resulting in exhaust gas of the internal combustion engine 10 results. The

Internal combustion engine 10 has an exhaust gas tract 22 through which the exhaust gas can flow, by means of which the exhaust gas is discharged from the cylinders 14.

In addition, the internal combustion engine 10 includes an exhaust gas turbocharger 24, which has a not visible in the figure, arranged in the exhaust tract 22 and driven by the exhaust gas turbine. Furthermore, the exhaust gas turbocharger 24 comprises a compressor, which is not visible in the figure and is arranged in the intake tract 16, by means of which the air flowing through the intake tract 16 is compressed. The compressor is driven by the turbine, so that the energy contained in the exhaust gas for

Compressing the air can be used.

Furthermore, a sensor in the form of a pressure sensor 26 is arranged in the intake tract 16, by means of which a pressure prevailing in the intake tract 16 pressure can be detected or detected. In the present case, the pressure sensor 26 is a Saugrohrdrucksensor, there by means of

Pressure sensor 26 a pressure prevailing in the suction pipe 18, which also as

Intake manifold pressure is called, is detected. In addition, the includes

Internal combustion engine 10 a venting device in the form of a

Crankcase breather 28, by means of which the housing member 12, i. the

Cylinder crankcase, is vented. The cylinder crankcase has a receiving space, which is not recognizable in the figure, which is referred to as crank space, since the crankshaft is received at least partially and in particular at least predominantly or completely in the crank space.

For example, in the context of a fired operation of the internal combustion engine, gas can flow from the cylinders 14 between the respective pistons and respective walls delimiting the respective cylinders 14 and into the

Flow in the crankcase. Since said walls define the respective cylinders 14, the walls are also referred to as cylinder walls or cylinder walls. The gas flowing from the cylinders 14 into the crankcase is also referred to as blow-by or blow-by-gas and can collect in the crankcase (receiving space). In order to avoid excessive, resulting from the blow-by pressure increase in the crankcase, the crankcase ventilation 28 is provided, by means of which the blow-by is discharged from the crank chamber. For this purpose, the crankcase breather 28 comprises at least one venting line 30, which is fluidically connected to the crankcase at a branching point. At a discharge point E, the vent line 30 is fluidly connected to the intake manifold 16. By means of the vent line 30, at least part of the blow-by at the branch point can be branched out of the crank chamber, wherein the branched blow-by flows through the vent line 30. That the

Vent line 30 flowing through blow-by (gas) can be introduced at the point of introduction E in the intake manifold 16, wherein the discharge point E upstream of the pressure sensor 26 and in particular upstream of the compressor is arranged.

In addition, a throttle element in the form of a throttle flap 32 is arranged in the intake tract 16, by means of which a quantity of the air flowing through the intake tract 16 can be adjusted. From the Fig. It can be seen that the throttle valve 32 in

Flow direction of the air through the intake manifold 16 upstream of the pressure sensor 26 is arranged, wherein the throttle valve 32 is disposed downstream of the compressor. Further, the discharge point E in the flow direction of the air through the intake manifold 16 upstream of the throttle valve 32 is arranged.

The blow-by contains components such as unburned hydrocarbons, which are passed together with the blow-by in the discharge point E in the intake manifold 16. The blow-by and thus the unburned contained in the blow-by

Hydrocarbons are entrained by the air flowing through the intake tract 16 and transported into the cylinder 1, where the unburned

Hydrocarbons participate in the combustion of the fuel-air mixture. As a result, the unburned hydrocarbons are burned and not released unburned to the environment.

From the Fig. It can be seen that the vent line 30 in the present case is designed as an external line and thereby as a full-load venting path, by means of which the

Recording space, especially at full load of the internal combustion engine 10, is vented or can be vented. Under the external line is to be understood that the vent line 30 is not integrated approximately in the housing member 12, but outside of the housing member 12, in particular outside of the crank chamber extends. In order to realize a particularly simple diagnosis, ie monitoring of the vent line 30, the internal combustion engine 10 comprises a diagnostic device 34. The diagnostic device 34 has at least one envelope 36, which surrounds at least one length region of the vent line 30. It can be seen from the FIG. That the vent line 30, with respect to its longitudinal extension, is accommodated at least predominantly or preferably completely in the enveloping line 36, which surrounds the vent line 30 in the circumferential direction of the vent line 30

preferably completely surrounds. In this case, the enveloping line 36 is spaced from the venting line 30, so that a diagnostic space 38 of the diagnostic device 34 arranged between the enveloping line 36 and the venting line 30 is provided. In the present case, the diagnostic space 38, which is also referred to as the control volume, is delimited on the one hand by the venting line 30 and on the other hand by the enveloping conduit 36.

The diagnostic device 34 also has a diagnostic line 40 which is fluidically connected to the diagnostic space 38 (control volume) at at least one first location 42. At at least one second point 44, the diagnostic line 40 is fluidically connected in the intake tract 16. In this case, the diagnostic device 34 further comprises the pressure sensor 26, by means of which at least one leakage of the venting line 30 arranged in the longitudinal region surrounded by the enveloping line 36 can be detected. From the Fig. It can be seen that the point 44 is arranged downstream of the pressure sensor 26. As a result of the fluidic connection of the diagnostic line 40 on the one hand with the

Diagnostic room 38 and on the other hand with the intake manifold 16, in particular the intake manifold 18, the diagnostic compartment 38 via the diagnostic line 40 fluidly connected to the intake manifold 16, in particular the suction pipe 18. Thus, in a normal operation, in which the vent line 30 has no leakage, the same pressure prevails in the control volume (diagnostic chamber 38) as in the suction tube 18.

In other words, the control volume prevails in this normal operation

Intake manifold pressure. If, for example, a leakage of the vent line 30 occurs, then at least part of the blow-by gas flowing through the vent line 30 can flow out of the vent line 30 via the leakage and into the vent line

Flow diagnostic chamber 38. As a result, the pressure prevailing in the diagnostic space 38 pressure is affected. As a result of the fluidic connection of the diagnostic space 38 via the

Diagnosis line 40 with the intake manifold 18 or the intake tract 16 is also affected by the leakage of the pressure prevailing in the intake manifold 18 and detectable by the pressure sensor 26 pressure, so that the pressure sensor 26 can be used to detect the leakage. In other words, the internal combustion engine 10 is based on the idea of using the pressure sensor 26 arranged downstream or behind the throttle flap 32 in order to detect a changing or changed pressure. this happens

for example, characterized in that by means of the pressure sensor 26, an actual pressure in the intake manifold 16, in particular in the intake manifold 18, is measured. If the measured actual pressure differs from a setpoint pressure or a setpoint signal, in particular if the pressure is closed

Throttle valve 32, this is detectable by means of the pressure sensor 26. Such a deviation occurs in the event of a leakage, so that this deviation and, as a consequence, the leakage can be detected by means of the pressure sensor 26.

Since the vent line 30 is received in the envelope 36, a tube-in-tube solution is provided at the crankcase vent 28. A leakage of the vent line 30, for example, to understand a leak of the vent line 30, wherein due to the leakage at least a portion of the blow-by gas can flow out of the vent line 30. However, since the vent line 30 is now received in the envelope 36, this can be due to the leak from the

Vent line 30 outflowing blow-by gas and in particular the hydrocarbons received in the blow-by gas does not readily reach the environment, but the blow-by gas emitted via the leakage from the vent line 30 is sent to the intake tract by means of the diagnostic line 40 16 out and can then flow into the cylinder 14.

In the exhaust tract 22, for example, at least one lambda probe is arranged, by means of which a residual oxygen content can be detected or detected in the exhaust gas of the internal combustion engine. The leakage or leakage of the vent line 30 can now be detected in the interaction of the lambda probe or the oxygen content detected by the lambda probe, the throttle valve 32, in particular its position, and the pressure sensor 26 or the pressure detected by the pressure sensor 26. As a result, the crankcase breather 28 may be diagnosed or monitored without the need for additional sensors. As a result, the number of parts, the weight, the space requirements and the cost of

Internal combustion engine 10 are kept low. LIST OF REFERENCE NUMBERS

10 internal combustion engine

12 housing element

14 cylinders

16 intake tract

18 intake manifold

20 air filters

22 exhaust tract

24 exhaust gas turbocharger

26 pressure sensor

28 crankcase breather

30 vent line

32 throttle

34 diagnostic device

36 envelope

38 diagnostic room

40 diagnostic line

42 first place

44 second place

E discharge point

Claims

claims

1. internal combustion engine (10), in particular for a motor vehicle, with an air-flowable intake tract (16) for guiding the air to at least one combustion chamber (14) of the internal combustion engine (10), with at least one in the intake tract (16) arranged sensor ( 26) for detecting a pressure in the intake tract (16), with at least one housing element (12) having at least one receiving space for at least partially receiving at least one shaft of the internal combustion engine (10), and at least one with the intake tract (16) and with the receiving space fluidly connected vent line (30), by means of which a gas from the

Removable receiving space and in the intake tract (16) can be introduced,

characterized in that

a diagnostic device (34) is provided which comprises at least one enveloping duct (36) surrounding at least one longitudinal region of the venting duct (30), at least one diagnostic chamber (38) arranged between the ductwork (36) and the longitudinal region, one with the diagnostic chamber (38) and the intake tract (16) fluidly connected diagnostic line (40) and the sensor (26), by means of which at least one arranged in the length range leakage of the vent line (30) can be detected.

2. internal combustion engine (10) according to claim 1,

characterized in that

the diagnostic line (40) is fluidically connected to the intake tract (16) at a location (44) arranged downstream of the sensor (26) in the direction of flow of the air through the intake tract (16).

3. internal combustion engine (10) according to claim 1 or 2,

characterized in that

in the intake tract (16) a throttle element (32) for adjusting an amount of the intake tract (16) flowing through the air is arranged.

4. internal combustion engine (10) according to claim 3,

characterized in that

the throttle element (32) is arranged in the flow direction of the air through the intake tract (16) upstream of the sensor (26).

5. internal combustion engine (10) according to claim 3 or 4,

characterized in that

the diagnostic line (40) at one in the flow direction of the air through the

Intake tract (16) downstream of the throttle element (32) arranged location (44) is fluidly connected to the intake manifold (16).

6. A method for operating an internal combustion engine (10) according to any one of the preceding claims.