CN113074067A

CN113074067A - Internal combustion engine and method for determining a leak at a fluid-conducting component thereof

Info

Publication number: CN113074067A
Application number: CN202110012944.0A
Authority: CN
Inventors: M·豪特沃格尔; S·韦迪格
Original assignee: Volkswagen Automotive Co ltd
Current assignee: Volkswagen Automotive Co ltd
Priority date: 2020-01-06
Filing date: 2021-01-06
Publication date: 2021-07-06
Anticipated expiration: 2041-01-06
Also published as: DE102020200038B4; DE102020200038A1; CN113074067B

Abstract

The invention relates to an internal combustion engine having a fuel tank (36), a tank ventilation line (38) and a venturi nozzle (30) arranged in a fluid-conducting component (16), wherein the fluid-conducting component (16) and/or the venturi nozzle (30) has an inflow channel (28), an inlet point (40) connected downstream of the inflow channel (28) in fluid connection with the tank ventilation line (38), and an outflow channel (32) connected downstream of the inlet point (40). The outflow section (48) of the venturi nozzle (30) downstream of the opening point (40) is surrounded by the component (16) in such a way that a detection chamber (46) is formed around the outflow section (48), wherein the detection chamber (46) has at least one inflow opening (50) via which the detection chamber (46) can be pressurized, and wherein at least one pressure sensor (76, 84) is arranged and designed for detecting a pressure which changes in the tank ventilation line (38) as a result of a leak in the detection chamber (46). The invention also relates to a method for determining a leakage at a fluid-conducting component (16) of such an internal combustion engine (10) according to claim 9.

Description

Internal combustion engine and method for determining a leak at a fluid-conducting component thereof

Technical Field

The invention relates to an internal combustion engine having at least one venturi nozzle arranged in a fluid-conducting component and to a method for determining a leakage at a fluid-conducting component of such an internal combustion engine.

Background

DE 102014012427 a1 discloses a vapor return line system of a fuel vapor collection container, which has a vapor outlet line with a first shut-off valve, which is arranged in the vapor outlet line of the fuel vapor collection container. A first vapor return line branch is arranged between the vapor outlet line of the fuel vapor collection container and the charge air line. A second steam return line branch is arranged between the steam outlet line of the fuel vapor collection container and a fresh air suction line of a compressor of the turbocharger. The first steam return line branch is coupled via a first check valve to the charge air line, and the second steam return line branch is coupled via a second check valve to the suction inlet of a venturi nozzle which is arranged via a second shut-off valve in the bypass line between the charge air line and the fresh air suction line. Although a plurality of sensors are described in connection with this system, it appears that no monitoring of the correct assembly and integrity of the venturi nozzle is provided.

DE 102014204187 a1 discloses a multiple evacuation injector system for a power machine with an injector that includes a restriction, first and second inlets, and an outlet and a shut-off valve that is securely mounted at the inlet of the power machine and coupled to the outlet. It is also disclosed that the ejector contains a venturi nozzle and that the shut-off valve should be configured to close in response to the shut-off valve being separated from the power machine inlet. In order to detect leaks, it is provided, in particular, to monitor the current through the shut-off valve in order to detect a separation.

From US 2016/0069304 a1, an internal combustion engine with a tank ventilation line and a venturi nozzle is known, wherein a pressure sensor is provided as an integral component of the venturi nozzle, by means of which pressure sensor the pulsations of the internal combustion engine and the defects that cause these pulsations are to be detected. Other embodiments are described in which sensors that detect pulsations are disposed at other locations of the internal combustion engine.

With some of the systems described above, certain faults, in particular minor leaks, which are caused by the plastic parts with the venturi nozzle breaking or by the venturi element not being inserted properly into the internal combustion engine, cannot be identified or can only be identified to a limited extent. These systems are also, in part, very expensive and thus costly to implement in practice.

Disclosure of Invention

The object of the invention is to provide an internal combustion engine having a fuel tank, a tank ventilation line and a venturi nozzle arranged in a fluid-conducting component, and a method for determining a leak at a fluid-conducting component of such an internal combustion engine, by means of which air containing fuel can be prevented from reaching the surroundings reliably and at manageable implementation costs.

The internal combustion engine according to the invention comprises a fuel tank, a tank ventilation line and a venturi nozzle arranged in the fluid-conducting component, wherein the fluid-conducting component and/or the venturi nozzle has an inflow channel which is in particular fluidically connected to a pressure pipe downstream of a compressor of the exhaust gas turbocharger. The fluid-conducting component and/or the venturi nozzle also have an inlet point (Muendungsstelle) which is fluidically connected to the tank ventilation line downstream of the inlet channel and an outlet channel which is fluidically connected downstream of the inlet point. The outflow channel opens in particular into the intake section upstream of the compressor of the exhaust-gas turbocharger. The flow of the intake air from the inflow channel to the outflow channel in the main flow direction through the venturi nozzle generates a negative pressure in the tank ventilation line at least in the case of an active compressor of the turbocharger, as a result of which ventilation of the fuel tank is achieved by means of the venturi nozzle. The outflow section of the venturi nozzle downstream of the opening point is surrounded by components of the intake section in such a way that a detection chamber is formed around the outflow section. The detection chamber has at least one inlet opening, via which the detection chamber can be pressurized. Furthermore, at least one pressure sensor is arranged and designed for detecting a pressure which changes in the tank ventilation line as a result of a leak in the detection chamber. For this purpose, the pressure sensor is arranged in particular on a section of the tank ventilation line, preferably on the following sections: this section is forced to flow through and therefore before the tank ventilation line can branch into the first section, the second section and, if appropriate, further sections. This constructive design makes it possible, in particular in connection with an inserted venturi nozzle or venturi element, to detect an incorrectly inserted connection and/or a defective venturi element or a defective venturi nozzle analytically, in particular by continuously and/or sampled monitoring of the pressure value of the pressure sensor and comparison with a setpoint value or a suitable value range. In other words, varying negative pressure in the tank vent line is used to detect leaks. With this type of monitoring and evaluation, a sensitive monitoring, which can be performed in particular in a plurality of operating states of the internal combustion engine, can be achieved.

It should be noted that a pressure sensor within the meaning of the present invention is any sensor with which a pressure can be measured or determined in another suitable way. In this connection, the concept also covers at least the pressure/temperature sensor combinations known from practice and other pressure sensor combinations.

In particular, the entire outflow channel is surrounded by a detection chamber formed by the component (in particular by the venturi element). In addition to the inflow opening or inflow openings, the detection chamber is preferably a closed chamber, i.e. a chamber which is suitably sealed with respect to other chambers which may be accessible via the gap if possible and with respect to the surroundings which may be accessible via the gap if possible, for example by suitably arranging a seal.

The following laws dictate: the tank ventilation system of the motor vehicle is monitored in such a way that it is ensured that tank ventilation gas is passed into the engine in order to be added for combustion. In particular, it is therefore necessary to detect the absence of a venturi nozzle, which is usually used in the tank ventilation line, being plugged and/or broken. These defects may occur as a result of maintenance not being performed as intended, in particular if the venturi nozzle is forgotten to be plugged in again. Damage that may occur during the entire life of the vehicle (material fatigue) must also be identified. Damage to the inflow channel of the venturi nozzle upstream of the opening point or an unplugged line can also be detected in the same manner, since in this case no negative pressure is generated in the tank ventilation line.

However, damage in the region of the venturi nozzle downstream of the opening point is problematic, since here, in particular for venturi nozzles having a greater length downstream of the opening point, particularly high lever forces act. In this regard, an imperceptible damage may result in the vapor containing fuel reaching the ambient environment for an extended period of time. Therefore, monitoring should be recommended or required in that area.

With the internal combustion engine according to the invention, damage in the outflow section can be reliably detected. This ensures that no fuel-containing intake air can pass from this region into the surroundings. The arrangement of the section of the venturi nozzle downstream of the opening point in the detection chamber formed by the component has two effects.

On the one hand, if the venturi nozzle is damaged only downstream of the opening point, the intake air containing fuel flows into the pressurized detection chamber without escaping from the detection chamber into the surroundings.

On the other hand, this section is particularly well protected against damage due to the arrangement of the section downstream of the opening point, which is surrounded by components of the intake section. If damage occurs-unlikely-in both the venturi nozzle and the components surrounding it, the volume of intake air present in the detection chamber is of such a size that the pressure drop caused by escaping intake air can be easily and reliably detected by the pressure detector.

The internal combustion engine according to the invention, which uses a surrounding arrangement of the venturi nozzle, thus suppresses damage to the venturi nozzle in the region of the section downstream of the opening point and, in addition, enables reliable detection if the venturi nozzle and surrounding components are damaged.

A comparison module is preferably provided, which compares the pressure values detected by means of the pressure sensor and/or the values derived therefrom and/or other measured values with setpoint values and, depending on the result, ascertains whether a leak is present in the region of the fluid-conducting component and/or the venturi nozzle. Such a comparison module is further preferably designed as a subcomponent or a related component of a so-called on-board diagnostic system (OBD), which is part of most motor vehicles with internal combustion engines.

Damage to the venturi nozzle is particularly well suppressed if all of the outflow section (i.e. the entire outflow channel) is surrounded by the component. The fluid-conducting component can also be designed to this end in such a way that the fluid-conducting component (in particular the venturi element) at least partially also surrounds the inflow duct and/or at least partially also surrounds the connection to the tank ventilation line. In this case, the detection chamber is designed such that a major part of the venturi nozzle or the entire venturi nozzle is enclosed by the fluid-conducting component and the detection chamber formed in this component. The venturi nozzle is thereby also effectively protected from external forces and damage in the corresponding sections and regions.

In a practical embodiment, the fluid-conducting component is a venturi element, an intake air guide hood and/or an exhaust gas turbocharger. The intake air flowing out of the venturi nozzle with the fuel-containing tank ventilation gas thus flows via the venturi element and/or via an intake air guide hood in fluid connection with the exhaust gas turbocharger directly into the intake section upstream of the exhaust gas turbocharger or directly into the exhaust gas turbocharger. In this case, the venturi element, the intake air guide hood itself and/or the exhaust gas turbocharger are in particular designed in such a way that at least one outflow section of the venturi nozzle downstream of the opening point is enclosed in such a way that the respective component (intake air guide hood or exhaust gas turbocharger) at least partially forms the detection chamber.

In particular, in order to pressurize the detection chamber with pressure, the input opening is fluidly connected with the pressure pipe downstream of the exhaust gas turbocharger or other component that can generate an increased pressure relative to the ambient pressure. In this case, the pressure pipe is coupled downstream of the compressor or other component of the exhaust-gas turbocharger. The compressed intake air flows from the pressure pipe toward the combustion chamber. A partial flow which opens into the inlet channel of the Venturi nozzle branches off from the pressure tube. This partial flow is in turn divided into two partial flows, one of which opens into the inlet channel of the venturi nozzle and one of which is used to pressurize the detection chamber with pressure. Whereby the same pressure is present in the venturi nozzle and the detection chamber. In particular, no additional pressure source is required for pressurizing the detection chamber, but the pressure provided by the compressor is used in a simple manner.

Alternatively or in addition to the pressure sensor upstream of the branching of the tank ventilation line into two or more branches, also suitable as a pressure sensor is a sensor arranged in the suction line downstream of the throttle valve. In this case, pressure sensors already present in most internal combustion engines can additionally or alternatively be used in order to monitor the pressure in the intake tract downstream of the exhaust-gas turbocharger and thus to carry out the desired detection of defects in the region of the venturi nozzle or the venturi element. No additional costs for the respective pressure sensor then arise.

In a further practical embodiment of the internal combustion engine according to the invention, the at least one inlet opening into the detection chamber is formed before or in the inflow channel of the venturi nozzle. In the case of an inflow opening formed in the inflow channel, the plurality of inflow openings opening into the detection chamber are preferably formed distributed over the circumference of the inflow channel. It is thus possible in particular to achieve a radial inflow of intake air into the detection chamber. The formation of the inlet opening in the inflow channel is a particularly space-saving solution. The sum of the diameters of all inlet openings is in particular at least 5mm, preferably at least 7mm, and particularly preferably at least 10 mm. In contrast thereto, the minimum diameter of the venturi nozzle is in particular at most 3mm, preferably at most 2.5mm, and in particular at most 2 mm.

In particular in connection with the inlet opening before the inflow channel, the at least one inlet opening into the detection chamber is preferably configured to be parallel to the flow of the inflow channel of the venturi nozzle, for example above, below or in the vicinity of the inflow channel. In particular, the inflow of intake air into the detection chamber takes place in a direction parallel to the inflow of intake air into the inflow channel. Parallel or axial inflow is a simple possibility for the intake air from a uniform mass flow to also flow into the detection chamber.

In order to achieve a flow of the intake air into the detection chamber parallel to the main flow direction, a connecting stub is arranged in the region of the inflow channel, in particular at the venturi nozzle, the inner diameter of which is greater than the inner diameter of the inflow channel. Such a connecting piece can be constructed in one piece with the venturi nozzle or be produced as a separate component and arranged accordingly. Upstream of the inflow channel, preferably first the entire partial flow flows into the connecting stub, where it is split into two partial flows, in particular a radially inner partial flow and a partial flow radially surrounding and surrounding it, which flow enters the inflow channel and the at least one inflow opening.

In another practical embodiment, the venturi nozzle is constructed in multiple parts. In particular, the inlet channel, the outlet channel and the connection for the tank ventilation line can be designed as separate elements which are only connected to one another when the internal combustion engine is assembled, for example by plugging together and/or welding. The venturi nozzle comprises in particular a base body, for example in the form of a venturi element, wherein the base body can be designed in one piece with the inflow channel, and a separate inflow channel and a connecting stub for a tank ventilation line are provided in the base body. Alternatively, the venturi nozzle may be constructed in one piece with the venturi element or another base body.

The venturi nozzle may also have two or more opening points which are fluidically connected to the tank ventilation line in order to bring about particularly effective tank ventilation. Accordingly, the venturi nozzle narrows in the region of the opening point. If a plurality of opening points are provided, in particular a section of the venturi nozzle which extends downstream of the first opening point viewed in the main flow direction is surrounded by the component and the detection chamber.

The invention is primarily realized in connection with a fluid-conducting member and/or a venturi nozzle in a fluid-conducting member, which is completely or partly made of plastic. Since the component, which is formed precisely from plastic, becomes brittle as a result of the material over a long service life and then fails suddenly. Such a failure can be detected using the internal combustion engine according to the invention.

The invention also relates to a method for determining a leak at a fluid-conducting component of an internal combustion engine as described above, according to which a pressure value detected by means of a pressure sensor is compared with a target value of a reference characteristic map in order to ascertain by means of the comparison whether a leak is present in the region of the fluid-conducting component and/or of a venturi nozzle.

In this case, it is preferred that in the open state of the tank ventilation valve at least one measurement is carried out with a pressure sensor arranged upstream or downstream of the tank ventilation valve and a comparison is carried out, and/or in the closed state of the tank ventilation valve at least one measurement is carried out with a pressure sensor arranged downstream of the tank ventilation valve and a comparison is carried out.

Reference is made here again to the advantages already described above in connection with the internal combustion engine.

Drawings

Other practical embodiments of the present invention will be described below with reference to the accompanying drawings. Wherein:

fig. 1 shows a structure of the illustrated type of an internal combustion engine according to the invention;

FIG. 2 illustrates in cross-section one embodiment of the area with the venturi nozzle and the detection chamber identified at II in FIG. 1;

FIG. 3 shows a further embodiment of the region with a venturi nozzle and a detection chamber, which is indicated by II in FIG. 1, in a sectional view; and

fig. 4 shows a pressure-time diagram.

Detailed Description

Fig. 1 shows a schematic representation of an internal combustion engine 10 according to the invention, wherein only those elements which may be important in connection with the invention are explained in detail below.

An intake section 12 is provided in the internal combustion engine 10, via which fresh air from the atmosphere can be supplied to a combustion chamber 14. As the fluid-conducting component 16 of the intake section 12, an intake air guide hood 18 is provided. Downstream of the intake air guide sleeve 18, a compressor of an exhaust gas turbocharger 20 and a throttle 22 follow.

The region downstream of the compressor is referred to as the pressure tube 24. At a branch 26 downstream of the exhaust-gas turbocharger 20, a partial flow T branches off from the pressure line 24, wherein this partial flow T is guided as a drive flow into an inflow channel 28 of a venturi nozzle 30. The outflow channel 32 of the venturi nozzle 30 is guided back into the intake air guide hood 18.

Via the outflow channel 32 and the intake air guide hood 18, the intake air is guided from the venturi nozzle 30 into the intake section 12 upstream of the exhaust gas turbocharger 20.

As can be seen in fig. 1, an optional pressure sensor 34 is arranged in the pressure pipe 24, here downstream of the branch 26 of the partial flow T.

Exhaust gas directed from the combustion chamber 14 flows to an exhaust device (not shown) via an exhaust turbocharger 20.

The internal combustion engine 10 also includes a fuel tank 36 that is vented via a tank vent line 38. A first branch 38a of the tank ventilation line 38 leads into an opening point 40 into the venturi nozzle 30. A second branch 38b of the tank ventilation line 38 leads into the region downstream of the throttle 22.

The section downstream of throttle 22 is also referred to as suction duct 82. In the embodiment shown in fig. 1, a pressure sensor 84 is arranged in the suction line 82.

Furthermore, in the path of the tank ventilation line 38, a first pressure sensor 44, a tank insulation valve (FTIV)72, an activated carbon reservoir 42, a tank leakage Diagnostic Module (DMTL)74 and a pressure sensor 76 are optionally arranged in each case. As a mandatory element, a tank ventilation valve (TEV)78 is arranged in the tank ventilation line 38. The pressure sensor 76 is arranged upstream of a tank ventilation valve (TEV) 78.

Alternatively, a tank vent valve 78', shown in phantom in fig. 1, may also be disposed upstream of the pressure sensor 76. The pressure sensor is then arranged downstream of the tank vent valve 78'.

As is also shown schematically in fig. 1 and explained in more detail below with reference to further figures, the venturi nozzle 30 is at least partially surrounded by a detection chamber 46, which is only shown in fig. 1 as a dashed box.

Fig. 2 shows a first embodiment of the venturi nozzle 30, which is embodied in one piece in the venturi element 86. An inflow channel 28 and an outflow channel 32 are formed in the venturi element 86, wherein the partial flow T used as the drive flow is introduced into the inflow channel 28. A first branch 38a of the tank ventilation line 38 opens out from above at an opening point 40, via which the venturi nozzle 30 is supplied with the suction flow S. As can be seen in fig. 1, the venturi element 86 and the suction connection 94 are each designed as plug elements which serve as a connecting connection 68 to the tank ventilation line 38 and as a connecting element, and which are introduced into the venturi element 86 from above. In the connecting region between the tank ventilation line 38 and the suction connection 94, a check valve 88 with a diaphragm 92 is arranged, which prevents a backflow from the venturi element 30 in the event of a negative pressure to the branch 38b and/or the tank ventilation valve 78. Alternatively, a non-return valve (not shown) may also be arranged further upstream outside the venturi nozzle in the branch 38b of the tank ventilation line 38.

The partial flow T branched off from the pressure tube 24 (see fig. 1) partially flows into the inflow channel 28 and further in the main flow direction through the venturi nozzle 30 toward the outflow opening of the outflow channel 32. Due to the geometric design, a negative pressure is generated in the tank ventilation line 38 in the region of the opening point 40, so that fuel-containing gases are actively conveyed out of the fuel tank 36 or from the activated charcoal container 42, which gases open into the intake section 12 via the outflow channel 32 upstream of the exhaust gas turbocharger 20 (see fig. 1).

In the illustration according to fig. 2, as a section downstream of the opening point 40, virtually the entire outflow channel 32 and virtually the entire opening point 40 of the tank ventilation line 38 are surrounded by the venturi element 86 in such a way that a detection chamber 46 is formed which surrounds these regions.

In the present case, the detection chamber 46 has two inflow openings 50 (or alternatively a circular inflow opening or inflow openings) via which the detection chamber 46 is filled with intake air and is thus subjected to a certain pressure (overpressure). The sealing of the detection chamber 46 with respect to the tank ventilation line 38 and with respect to the outflow channel 32 is effected in the present case via an O-ring 52. Alternatively, sealing with respect to the inflow channel 28 may also be accomplished in the same manner (not shown), provided such sealing is structurally desirable and/or meaningful.

As can be seen clearly in fig. 2, the partial flow T branching off from the pressure tube 24 is split off on account of the constructive design of the venturi element 86 in such a way that one partial flow is guided into the venturi nozzle 30 and the other partial flow is guided into the detection chamber 46 via the inflow opening 50. The same pressure thus prevails in the venturi nozzle 30 as in the detection chamber 46.

Fig. 3 shows a further exemplary embodiment with an inflow duct 28, an opening point 40 arranged in the venturi nozzle 30 and an outflow duct 32, wherein, in connection with this embodiment, the same reference numerals as in fig. 2 are used for identical or at least functionally identical elements. The main difference of this embodiment is that the venturi nozzle 30 is produced as a separate component and is inserted into the venturi element 86 which is produced as a separate component. Furthermore, it is a double venturi nozzle 30, i.e. two opening points 40 are provided, in which the partial flow T is supplied with fluid from the suction flow S of the tank ventilation line 38. Furthermore, the detection chamber 46 is designed such that it extends over only a part of the circumference and serves only to monitor the outflow channel 32.

In the embodiment shown in fig. 3, the suction connection 94 is integrally molded on the venturi element 86, so that the tank ventilation line 38 can be connected directly to the suction connection 94 by means of a plug connection.

The embodiments shown in fig. 2 and 3 are merely examples of two different variants. In fact there are many further variants, all of which can be combined with the invention, for example also such variants: a suction connection 94 with a bent-over suction connection, a suction connection 94 with a plurality of further individual elements and with other types of non-return valves and/or without non-return valves in the suction connection itself. A suitable check valve may also be provided further upstream in the tank ventilation line 38.

The operating principle of the internal combustion engine 10 according to the invention is explained below with reference to the diagram in fig. 4. When the tank vent valve 78 is open, the current pressure in the tank vent line 38 may be determined by means of the pressure sensor 76, or alternatively by means of another sensor arranged at a suitable location in the tank vent line 38. The measured pressure values are then compared with a value range, which is known from a characteristic map or other mapping table for the respective operating point of the internal combustion engine and is stored in a memory. The solid line 54 in fig. 4 represents the measured value for the pressure P, which is determined in normal operation by the pressure sensor 84 of the pressure sensor 76 during a defined, constant operating state. The two

solid lines

56, 58 arranged above and below it represent the measurement tolerances within which the measured pressure is allowed to fluctuate in the case of a specified operation.

In contrast, in the internal combustion engine 10 according to the invention, if a situation arises which would lead to the intake air containing fuel possibly reaching the surroundings, for example because the venturi nozzle 30 or the venturi element 86 is inserted incorrectly and/or because one of these elements breaks, a significant pressure drop occurs in the tank ventilation line 38 according to the dash-and-dot line 62 in fig. 3. This pressure drop is outside the measurement tolerance of the pressure sensor 76, so that it can be detected by the evaluation unit associated with this pressure sensor 76. The fuel-containing intake air flowing out of the damaged venturi nozzle 30 upstream of the opening point 40 can thus be prevented from reaching the surroundings imperceptibly.

For the sake of completeness, it is pointed out that the evaluation as described above is possible even with the tank ventilation valve 78 'closed if the pressure sensor 76 is arranged downstream of the tank ventilation valve 78'.

It is further noted that the measurement can be carried out with a pressure sensor arranged only in the branch 38a of the tank ventilation line 38. This measurement is only meaningful when: this branch 38a is suitable for detecting faults, such as for example a defective venturi element 86 and/or an incorrectly inserted venturi nozzle and/or an incorrectly inserted venturi element 86, on the basis of the operating state of the internal combustion engine 10. This is particularly the case when: a negative pressure occurs in the branch 38a, as a result of which a fluid flow occurs with the tank ventilation valve 78 open.

The features of the invention disclosed in the description and the drawings are essential for the realization of the invention in its various embodiments both individually and in any combination. The present invention may be modified in view of the knowledge of the person skilled in the relevant art.

List of reference numerals:

10 internal combustion engine

12 air inlet section

14 combustion chamber

16 fluid-conducting member

18 air inlet air guide cover

20 exhaust gas turbocharger

22 throttle valve

24 pressure pipe

26 branch

28 inflow channel

30 Venturi nozzle

32 outflow channel

34 pressure sensor

36 fuel tank

38 tank vent line

38a first branch of the tank ventilation circuit

38b second branch of tank ventilation circuit

40 access position

42 activated carbon container

44 pressure sensor

46 detection chamber

48 outflow section

50 inflow opening

52O-shaped ring

54 line

56 line

58 line

60 line

62 line

64 coupling part

66 base body

68 connecting joint

72 fuel tank isolation valve

74 oil tank leakage diagnosis module

76 pressure sensor

78 oil tank vent valve

80 drive beam circuit

82 suction tube

84 pressure sensor (in the suction tube)

86 Venturi element

88 check valve

90 check valve

92 diaphragm

94 suction connection.

Claims

1. Internal combustion engine having a fuel tank (36), a tank ventilation line (38) and a venturi nozzle (30) arranged in a fluid-conducting component (16), wherein the fluid-conducting component (16) and/or the venturi nozzle (30) has an inflow channel (28), an opening point (40) which is fluidically connected to the tank ventilation line (38) downstream of the inflow channel (28), and an outflow channel (32) which is downstream of the opening point (40),

it is characterized in that the preparation method is characterized in that,

an outflow section (48) of the venturi nozzle (30) downstream of the opening point (40) is surrounded by the component (16) in such a way that a detection chamber (46) is formed around the outflow section (48), wherein the detection chamber (46) has at least one inflow opening (50) via which the detection chamber (46) can be acted upon with pressure, and wherein at least one pressure sensor (76, 84) is arranged and designed for detecting a pressure which changes in the tank ventilation line (38) as a result of a leak in the detection chamber (46).

2. Internal combustion engine according to the preceding claim, characterized in that the pressure sensor (76, 84) is arranged in a section of the tank ventilation line (38, 38 a).

3. Internal combustion engine according to one of the preceding claims, characterized in that a comparison module is provided which compares the pressure values detected by means of the pressure sensors (76, 84) and/or values derived therefrom and/or other measured values with nominal values and, depending on the result, confirms whether a leak is present in the region of the fluid-conducting component (16) and/or the venturi nozzle (30).

4. An internal combustion engine according to any one of the preceding claims, characterized in that the connection (64) of the inflow channel (28) to the tank ventilation line (38) and/or at least partially is also surrounded by the fluid-conducting member (16).

5. Internal combustion engine according to one of the preceding claims, characterized in that, for loading the detection chamber (46) with pressure, the inflow opening (50) is fluidly connected with the pressure pipe (24) downstream of the exhaust-gas turbocharger (20) or other component capable of generating an increased pressure relative to the ambient pressure.

6. Internal combustion engine according to one of the preceding claims, characterized in that the at least one inflow opening (50) into the detection chamber (46) is configured before or in the inflow channel (28) of the venturi nozzle (30) and/or that the at least one inflow opening (50) into the detection chamber (46) is configured to flow parallel to the inflow channel (28) of the venturi nozzle (30).

7. Internal combustion engine according to any one of the preceding claims, characterized in that a coupling nipple (68) is provided upstream of the inflow channel (28) of the venturi nozzle (30) and/or upstream of the opening location (40) which is fluidly connected with the tank ventilation line (38).

8. An internal combustion engine according to any one of the preceding claims, characterized in that the venturi nozzle (30) is constructed in multiple parts and/or the fluid-conducting member (16) is completely or partially made of plastic.

9. Method for determining a leak at a fluid-conducting component (16) of an internal combustion engine (10) according to one of claims 1 to 8, characterized in that the pressure values detected by means of the pressure sensor (76, 84) are compared with nominal values of a reference characteristic map in order to ascertain by means of the comparison whether a leak is present in the region of the fluid-conducting component (16) and/or the venturi nozzle (30).

10. Method according to the preceding claim, characterized in that at least one measurement with a pressure sensor (76, 84) arranged upstream or downstream of a tank vent valve (78, 78') is performed in the open state of the tank vent valve (78, 78') and a comparison is performed, and/or at least one measurement with a pressure sensor (76, 84) arranged downstream of the tank vent valve (78) is performed in the closed state of the tank vent valve (78') and a comparison is performed.