METHOD AND DEVICE FOR MONITORING THE FUNCTIONING OF A CRANKCASE VENTILATION SYSTEM OF AN INTERNAL COMBUSTION ENGINE

Abstract

A method and a device for monitoring the functioning of a crankcase ventilation system of an internal combustion engine, crankcase ventilation gas being supplied to an intake line of the internal combustion engine via at least one crankcase ventilation line from the crankcase via an oil separator and a crankcase pressure regulating valve. An immediate surrounding environment of the internal combustion engine is monitored by at least one sensor that is sensitive to crankcase ventilation gas or to at least one crankcase ventilation gas component for the occurrence of crankcase ventilation gas, and that, if a presence of crankcase ventilation gas is determined, an informative or warning message is produced.

Claims

1. A method for monitoring the functioning of a crankcase ventilation system of an internal combustion engine, crankcase ventilation gas being supplied to an intake line of the internal combustion engine via at least one crankcase ventilation line from the crankcase via an oil separator and a crankcase pressure regulating valve, comprising the steps: monitoring an immediate surrounding environment of the internal combustion engine by at least one sensor that is sensitive to crankcase ventilation gas or to at least one crankcase ventilation gas component for the occurrence of crankcase ventilation gas, and producing an informative or warning message if a presence of crankcase ventilation gas is determined.

2. The method as recited in claim 1, wherein the at least one sensor monitors the occurrence of at least one of the following: carbon dioxide, water vapor, carbon monoxide, nitrogen oxides, and hydrocarbons.

3. The method as recited in claim 1, wherein the at least one sensor monitors the occurrence of volatile organic compounds.

4. The method as recited in claim 1, wherein the at least one sensor monitors the occurrence of solid and/or liquid particles in the air in the immediate surrounding environment of the internal combustion engine.

5. The method as recited in claim 1, wherein a reference measurement is carried out by the at least one sensor while the internal combustion engine is at a standstill and is cold, operating measurements are carried out while the internal combustion engine is running, the measurement results of the operating measurements are compared with the measurement result of the reference measurement, and, if differences are present that exceed a specifiable boundary value, the informative or warning message is produced.

6. The method as recited in claim 1, wherein the monitoring is carried out while the internal combustion engine is running, by operating measurements using at least two sensors situated at different locations in the immediate surrounding environment of the internal combustion engine, and wherein the measurement results of the at least two sensors are compared to one another, and wherein, if differences are present that exceed a specifiable boundary value, the informative or warning message is produced.

7. The method as recited in claim 5, wherein it is carried out at the internal combustion engine of a motor vehicle, and wherein operating measurements are carried out while the motor vehicle is traveling or is at a standstill.

8. The method as recited in claim 1, wherein the at least one sensor is activated only if an excess pressure, relative to an ambient air pressure, prevails in the crankcase of the internal combustion engine.

9. The method as recited in claim 1, wherein data obtained at the internal combustion engine by the at least one sensor are communicated to a central data evaluation center, and are evaluated there by comparison with one another in order to find an internal combustion engine that deviates from target data or mean value data, and wherein a signal that triggers an informative or warning message at a relevant, deviating internal combustion engine or a motor vehicle having an internal combustion engine is communicated back to such engine or vehicle.

10. The method as recited in claim 1, wherein data obtained at the internal combustion engine by the at least one sensor are communicated to other internal combustion engines or motor vehicles having an internal combustion engine, and are evaluated there by comparison with one another in order to find internal combustion engines that deviate from target data or mean value data, and wherein a signal that triggers an informative or warning message at relevant, deviating internal combustion engines or motor vehicles having an internal combustion engine is communicated back to these engines or vehicles or is produced at these engines or vehicles themselves.

11. A device for monitoring the functioning of a crankcase ventilation system of an internal combustion engine, at least one crankcase ventilation line being routed from the crankcase to an intake line of the internal combustion engine, and an oil separator and a crankcase pressure regulating valve being situated in the course of the crankcase ventilation line, comprising: at least one sensor situated in an immediate surrounding environment of the internal combustion engine that is sensitive to a crankcase ventilation gas or to at least one crankcase ventilation gas component, by which sensor an occurrence of crankcase ventilation gas can be determined, and, if there is a determination of a presence of crankcase ventilation gas, an informative or warning display assigned to the internal combustion engine can be activated.

12. The device as recited in claim 11, wherein at least one sensor is sensitive to at least one of the following: carbon dioxide, water vapor, carbon monoxide, nitrogen oxides, and hydrocarbons.

13. The device as recited in claim 11, wherein the at least one sensor is sensitive to volatile organic compounds.

14. The device as recited in claim 11, wherein the at least one sensor is sensitive to solid and/or liquid particles in the air in the immediate surrounding environment of the internal combustion engine.

15. The device as recited in claim 11, further comprising a microprocessor having a comparator, a reference measurement being capable of being carried out by the at least one sensor while the internal combustion engine is at a standstill and is cold, and operating measurements being capable of being carried out while the internal combustion engine is running, the measurement results of the operating measurements and the measurement result of the reference measurement being capable of being compared to one another by the comparator, and, if differences determined by the comparator are present that exceed a specifiable boundary value, the informative or warning display being capable of being activated.

16. The device as recited in claim 11, further comprising at least two sensors situated at different locations in the immediate surrounding environment of the internal combustion engine, and a microprocessor having a comparator, operating measurements being capable of being carried out with the at least two sensors while the internal combustion engine is running, the measurement results of the at least two sensors being capable of being compared to one another by the comparator, and, if differences determined by the comparator are present that exceed a specifiable boundary value, the informative or warning display being capable of being activated.

17. The device as recited in claim 15, wherein the device is situated at the internal combustion engine of a motor vehicle, and wherein operating measurements are capable of being carried out while the motor vehicle is one of traveling or at a standstill.

18. The device as recited in claim 11, further comprising a crankcase pressure measurement sensor, and wherein the at least one sensor is capable of being activated only when the crankcase pressure measurement sensor in the crankcase of the internal combustion engine determines the presence of an excess pressure relative to an ambient air pressure.

19. The device as recited in claim 11, wherein the at least one sensor is situated in an intermediate space between a cylinder head hood and a covering or design hood, situated thereabove, of the internal combustion engine.

20. The device as recited in claim 19, wherein the at least one sensor is situated in an end region, at the air outflow side, of the intermediate space.

21. The device as recited in claim 17, wherein the at least one sensor is situated in an end region, at the air outflow side, of an engine compartment of the internal combustion engine, below an engine hood of the motor vehicle.

22. The device as recited in claim 11, wherein a radio interface is allocated to an engine control device of the internal combustion engine, as a wireless data transmission device, data obtained at the internal combustion engine by the at least one sensor being capable of being communicated by the radio interface to a central data evaluation center, also having a radio interface, and there being capable of being evaluated by comparison with data from other sensors associated with other internal combustion engines in order to find internal combustion engines that deviate from target data or mean value data, and a signal that activates an informative or warning display at relevant, deviating internal combustion engines being capable of being communicated back to these engines.

23. The device as recited in claim 11, further comprising a radio interface, as a wireless data transmission device, and a microprocessor, as a decentral data evaluation device, are allocated to an engine control device of the internal combustion engine, data obtained at the internal combustion engine by the at least one sensor being capable of being communicated to other internal combustion engines and being capable of being evaluated by comparison with data from other sensors associated with the other internal combustion engines in order to find internal combustion engines that deviate from target data or mean value data, and a signal that activates an informative or warning display at relevant, deviating internal combustion engines being capable of being communicated back to these engines, or being capable of being produced in the separate decentral data evaluation device.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In the following, exemplary embodiments of the present invention are explained on the basis of a drawing.

[0035] FIG. 1 shows a motor vehicle having a device for monitoring the functioning of the crankcase ventilation system of its internal combustion engine, in a schematic cross-section through the engine compartment of the motor vehicle,

[0036] FIG. 2 shows an internal combustion engine together with a device for monitoring the functioning of its crankcase ventilation system, in a schematic view, and

[0037] FIG. 3 shows a part of the device for monitoring the functioning of the crankcase ventilation system in a further embodiment, in a schematic view.

[0038] In the following description of the Figures, identical parts in the various figures of the drawing have always been provided with the same reference characters, so that all reference characters do not have to be again explained for each figure of the drawing.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0039] FIG. 1 of the drawing shows a motor vehicle 6 having a device 1 for monitoring the functioning of the crankcase ventilation system of its internal combustion engine 5, in a schematic cross-section through the engine compartment 61 of motor vehicle 1.

[0040] In engine compartment 61, an internal combustion engine 5 is situated in a standard manner, having a crankcase 51, an oil pan 51 at the lower side, and having at the upper side a cylinder head hood 52 with a design hood 52 situated thereabove. Moreover, motor vehicle 6 has, in a standard manner, a chassis having axles 62, springs 63, and wheels 64. At the lower side, engine compartment 61 is covered by a lower engine compartment cover 65, and at the upper side it is covered by an engine hood 66.

[0041] In engine compartment 61, a plurality of, here a total of six, sensors 2.1 through 2.6 are situated at various locations, which sensors are sensitive to crankcase ventilation gas or to at least one crankcase ventilation gas component. A first sensor 2.1 is situated in an intermediate space 53 between cylinder head hood 52 and design hood 52. A second sensor 2.2 is situated in a laterally offset fashion and higher up in engine compartment 61, under engine hood 66.

[0042] When there is a leak in the crankcase ventilation system of internal combustion engine 5, an undesired emission of crankcase ventilation gas is to be expected, with highest probability, at the upper region of cylinder head hood 52, because as a rule the line or lines for the crankcase ventilation system run there, or are integrated in cylinder head hood 52.

[0043] Reference character 20 indicates a crankcase ventilation gas cloud that is emitted to the surrounding environment when there is a leak of the crankcase ventilation system. In the example shown in FIG. 1, the presence of the crankcase ventilation gas cloud is recognized on the one hand by first sensor 2.1, and subsequently also by second sensor 2.2, and is forwarded, in the form of electrical measurement signals, to an electronic evaluation unit (not shown in FIG. 1), for example in the form of a microprocessor, that is allocated to internal combustion engine 5 or to motor vehicle 6.

[0044] Depending on the airflow conditions prevailing in engine compartment 61 of motor vehicle 6, which are influenced by the travel speed of motor vehicle 6, by one or more cooling fans of internal combustion engine 5, and/or by wind in the surrounding environment of motor vehicle 6, in case of disturbance, emitted crankcase ventilation gas also moves into the region of one or more other sensors 2.1 through 2.6. The situation and distribution of sensors 2.1 through 2.6 is therefore selected such that an emission of crankcase ventilation gas is always recognized with adequate reliability under, to the greatest possible extent, all occurrent external influences and conditions.

[0045] By comparing the measurement data acquired by sensors 2.1 through 2.6 with reference data stored in the evaluation unit, it can be determined whether the crankcase ventilation system of internal combustion engine 5 is functioning properly, or whether a case of disturbance is present, with emission of crankcase ventilation gas to the surrounding environment. In the latter case, the evaluation unit activates an informative or warning display that brings the determined error to the attention of a user of motor vehicle 6, and prompts the user to remedy the error.

[0046] In addition, it can be provided that the evaluation unit prevents internal combustion engine 5 from being started if a determined error of the crankcase ventilation system is not remedied within a specifiable time span.

[0047] FIG. 2 shows an internal combustion engine 5 together with a device 1 for monitoring the functioning of the crankcase ventilation system of internal combustion engine 5, in a schematic view.

[0048] Here as well, internal combustion engine 5 has a crankcase 51 having an oil pan 51 at the lower side and having a cylinder head hood 52 at the upper side. Above cylinder head hood 52, design hood 52 is shown, here lifted and removed from cylinder head hood 52. Additionally shown in FIG. 2 are an air filter housing 54, an intake line 55 going out from this air filter housing and having a throttle valve 56 situated therein, and a turbocharger 57 having an air compressor 57 situated in the course of intake line 55.

[0049] At the upper side of cylinder head hood 52, there runs (shown schematically here) a crankcase ventilation line 58 that stands in a flow connection with the interior of the cylinder head and of crankcase 51, via an oil separator 59. In the direction of flow, behind oil separator 59 crankcase ventilation line 58 branches into two lines, which open in a known manner into intake line 55 via a respective check valve 58 upstream from compressor 57 or downstream from throttle valve 56. In normal operation of internal combustion engine 5, no crankcase ventilation gas can be emitted to the surrounding environment from this closed system.

[0050] Moreover, here there is a crankcase ventilation line 59 that branches off from intake line 55 downstream from air filter housing 54, and opens into the cylinder head and into crankcase 51.

[0051] Here, a total of five sensors 2.1 through 2.5 that are sensitive to crankcase ventilation gas or to at least one crankcase ventilation gas component are situated at the upper side of cylinder head hood 52, and are connected electrically, via a respective measurement signal line 32, to a microprocessor 3 that is allocated to internal combustion engine 5 or to an associated motor vehicle. For reasons of clarity, here only some of the measurement signal lines 32 are shown in the drawing; in reality, of course, all sensors 2.1 through 2.5 are connected to microprocessor 3. These connections can also be wireless instead of line-bound.

[0052] In addition, here a crankcase pressure measurement sensor 2.7 is situated on internal combustion engine 5, with which the pressure currently prevailing in crankcase 51 of internal combustion engine 5 can be measured, and can be communicated to microprocessor 3 via a further measurement signal line 32.

[0053] When design hood 52 is placed onto cylinder head hood 52, there is an intermediate space between these two components in which sensors 2.1 through 2.5 are then situated, which, in the case of a leakage of crankcase ventilation line 58, or some other leak that may possibly exist, detect the presence of crankcase ventilation gas emitting from internal combustion engine 5, and report it to microprocessor 3.

[0054] Because emission of crankcase ventilation gas from internal combustion engine 5 to the surrounding environment is possible only if an excess pressure relative to the ambient air pressure is present in crankcase 51, it suffices to activate sensors 2.1 through 2.5 only when the named boundary condition is present, which can be determined by crankcase pressure measurement sensor 2.7.

[0055] Microprocessor 3, which receives and processes the measurement signals of the (here five) sensors 2.1 through 2.5 and crankcase pressure measurement sensor 2.7, is here connected to an engine control device 4 of internal combustion engine 5 via a data connection such as a bus system 33, in order to communicate data and/or evaluation results to engine control device 4. Engine control device 4 is connected to an informative or warning display 41 by which a driver of a motor vehicle equipped with internal combustion engine 5 is informed of a disturbance that may be present of the crankcase ventilation system of internal combustion engine 5.

[0056] In addition, here engine control device 4 is equipped with a radio interface 40 that makes it possible for engine control device 4 to enter wirelessly into contact and data exchange with other, external units, as is explained in the following on the basis of FIG. 3.

[0057] FIG. 3 shows a part of device 1 for monitoring the functioning of the crankcase ventilation system in a further embodiment, in a schematic view.

[0058] At left in FIG. 3 are shown, as parts of the internal combustion engine 5 described above, its microprocessor 3 with measurement signal lines 32 running to it, as well as engine control device 4, with its radio interface 40, connected to microprocessor 3 via bus system 33.

[0059] Via this radio interface 40, engine control device 4 stands in wireless connection to a central data evaluation center 7, such as a data server, which has an allocated radio interface 70, or stands in wireless connection to additional motor vehicles 6, each having an associated radio interface 60, and equipped as shown in FIG. 2, or stands in wireless connection with both central data evaluation center 7 and with further motor vehicles 6.

[0060] With this, the possibility is created that data obtained at individual internal combustion engines 5, by their sensors, are communicated to central data evaluation center 7, and are evaluated there by comparison with one another in order to find internal combustion engines 5 that deviate from target data or mean value data, and that a signal that triggers an informative or warning message at relevant, deviating internal combustion engines 5, or motor vehicles 6 having an internal combustion engine 5, i.e., those having an emission of crankcase ventilation gas to the surrounding environment, is communicated back to these engines or vehicles.

[0061] Alternatively, or at the same time, here there exists the possibility that data obtained at individual internal combustion engines 5, by their sensors, are communicated to other internal combustion engines 5 or motor vehicles 6 having internal combustion engines 5, and are evaluated by comparison with one another in order to find internal combustion engines 5 that deviate from target data or mean value data, and that a signal that triggers an informative or warning message at relevant deviating internal combustion engines 5, or motor vehicles 6 having internal combustion engine 5, having an emission of crankcase ventilation gas to the surrounding environment, is communicated back to these engines or vehicles, or is produced at these engines or vehicles themselves.

[0062] Through the networking according to FIG. 3, a high degree of redundancy is achieved in the monitoring of the crankcase ventilation system of many internal combustion engines 5. In addition, in this way data from a multiplicity of internal combustion engines 5 can be collected and evaluated at a higher level.

[0063] As is apparent from the foregoing specification, the invention is susceptible of being embodied with various alterations and modifications which may differ particularly from those that have been described in the preceding specification and description. It should be understood that I wish to embody within the scope of the patent warranted hereon all such modifications as reasonably and properly come within the scope of my contribution to the art.

LIST OF REFERENCE CHARACTERS

[0064] 1 device [0065] 2.1-2.6 sensors for crankcase ventilation gas [0066] 2.7 crankcase pressure measurement sensor [0067] 20 crankcase ventilation gas cloud [0068] 3 microprocessor [0069] 32 measurement signal lines [0070] 33 bus system [0071] 4 engine control device [0072] 40 radio interface at 4 [0073] 41 informative or warning display [0074] 5 internal combustion engine [0075] 51 crankcase [0076] 51 oil pan [0077] 52 cylinder head hood [0078] 52 design hood [0079] 53 intermediate space between 52 and 52 [0080] 54 air filter housing [0081] 55 intake line [0082] 56 throttle valve [0083] 57 turbocharger [0084] 57 compressor of 57 [0085] 58 crankcase ventilation line [0086] 58 check valves in 58 [0087] 59 oil separator in 58 [0088] 59 crankcase ventilation line [0089] 6 motor vehicles [0090] 60 radio interface at 6 [0091] 61 engine compartment [0092] 62 axles [0093] 63 springs [0094] 64 wheels [0095] 65 lower engine compartment cover [0096] 66 engine hood [0097] 7 central data evaluation center [0098] 70 radio interface at 7