DE102015004716A1 - Device for checking the tightness of a tank and modular system for several construction variants of such a device - Google Patents

Abstract

The invention relates to a device (10) for checking the tightness of a tank (12) for storing a fuel (14) for an internal combustion engine, comprising at least one pressure sensor (34) for detecting a pressure in the tank (12), with at least one flushing channel (30) for carrying purge air to an adsorption filter (22) for filtering fuel components from gas from the tank (12), including at least one valve (36) for fluidically blocking the purge passage (30) and a pump (38) for delivery of air into the tank (12), wherein a first module component (46) comprising at least at least indirectly the adsorption filter (22) and the pressure sensor (34), the flushing channel (30) and the valve (36) and a pump ( 38) comprehensive, second module component (50) are provided, which is reversibly releasably connectable to the first module component (46).

Description

The invention relates to a device for checking the tightness of a tank according to the preamble of claim 1 and a modular system for a plurality of construction variants of such a device.

Such a device for checking the tightness of a tank for storing a fuel, in particular a liquid fuel, an internal combustion engine, for example, is already the DE 197 09 903 A1 to be known as known. The device comprises at least one pressure sensor, by means of which a pressure in the tank can be detected. Further, the apparatus comprises at least one purge passage for guiding purge air to an adsorption filter for filtering fuel components from gas from the tank. The device further comprises at least one valve for fluidically blocking the flushing channel and a pump, by means of which air can be conveyed into the tank or can be conveyed.

To operate the internal combustion engine in a fired operation, it is supplied with the fuel from the tank. If the internal combustion engine is deactivated over a long period of time and there is still fuel, in particular liquid fuel, in the tank, the fuel can outgas. By this is meant that a gas from the fuel collects in the tank, which gas comprises volatile fuel components and thus fuel vapors. In order to avoid excessive pressure rise in the tank resulting from the outgassing, the gas resulting from the outgassing is discharged from the tank to the environment via a vent line. In order to avoid that an excessive amount of unburned hydrocarbons from the fuel components reaches the environment, the gas is usually passed through the absorption filter, in particular an activated carbon filter, before the gas is finally discharged to the environment. By means of the adsorption filter unburned hydrocarbons are filtered from the gas. As a result, the emissions of unburned hydrocarbons, so-called HC emissions, can be kept low.

If the tank has, for example, a leak, then the gas and thus the fuel constituents or unburned hydrocarbons can reach the environment via this leak, without the gas being passed through the adsorption filter. The device is now used to detect such a leak or leakage early, so that particularly early countermeasures can be taken to avoid excessive HC emissions.

In order to check the tightness of the tank, that is, to check the tank for leaks, air is conveyed into the tank, the air being pumped into the tank by means of the pump. Then, for example, it is possible by means of the pressure sensor on the basis of the determined by this, prevailing in the tank pressure to detect any leaks in the tank. By filtering the fuel constituents, the adsorption filter increases with the fuel constituents. The purge air now serves to receive and purge the fuel components from the adsorption filter and to lead into an intake tract of the internal combustion engine.

Further, the DE 10 2013 216 998 A1 a method for an engine, wherein a deterioration of the fuel system is indicated in response to a change in the fuel system pressure after exerting an overpressure, which is generated in an electrically operated vacuum pump.

Conventional devices for checking the tightness of a tank have a plurality of individual components such as the pressure sensor, the flushing channel, the valve and the pump, resulting in a high complexity of the device. The device is thus usually very time consuming and costly to assemble.

Object of the present invention is therefore to provide a device of the type mentioned above and a modular system by which a time-consuming and cost-effective installation of the device can be realized.

This object is achieved by a device with the features of claim 1 and by a modular system having the features of claim 4. Advantageous embodiments with expedient developments of the invention are specified in the remaining claims.

In order to further develop a device of the kind specified in the preamble of patent claim 1 in such a way that a particularly simple assembly of the device can be realized, a first module component which can be connected at least indirectly, in particular reversibly detachably, is provided which connects the pressure sensor to the flushing channel and the valve comprises. Furthermore, a second module component is provided, which comprises the pump and is reversibly releasably connectable to the first module component. The respective module component is a component unit or an assembly which is assembled or independent of the respective other module component or assembly, that is, can be manufactured and assembled. In particular, it is possible that produce respective module component independently of the tank, so that the respective module component can be produced in time and inexpensively or mounted. After the production of the respective module component, it is possible to handle the module component and thus its components, ie in the case of the first module component, the pressure sensor, the flushing channel and the valve and in the case of the second module component, the pump as a whole, so that the respective components not must be handled and assembled individually.

In this case, the first module component is a basic module and comprises, for example, a housing in which the pressure sensor and the valve acting as shut-off valve are installed, and the flushing channel is or is arranged. The second module component is a pump module or air pump module, which can be reversibly detachably connected, that is to say connected to the first module component or the basic module so as to be non-destructively releasable, and detached therefrom. As a result, a modular construction of the device is provided, whereby the air pump module can be adapted to the base module, for example, by simply plugging in and fixing. It is conceivable to arrange the pump within the housing or outside of this.

Because the air pump module can be reversibly detachably connected to the basic module, the basic module can be equipped as required with the air pump module. This makes it possible, for example, for a first construction variant of the internal combustion engine to use only the basic module without the air pump module, wherein for a second construction variant of the internal combustion engine, the basic module can be used together with the air pump module. In other words, it is possible due to the modular structure to create different construction variants of the device in a particularly simple and cost-effective manner.

By connecting the air pump module to the base module, a diagnostic module for checking the tightness of the tank can be created because the pump can be used to convey air into the tank. Then it is possible to determine from the pressure detected by the pressure sensor in the tank, whether the tank has a leak or not. In particular, it is thus possible to use the device in a particularly cost-effective manner both for conventional tanks and for hybrid tanks. In the case of the hybrid tank and the conventional tank always the same pressure sensor, the same valve and the same flushing channel are installed, that is, the hedging effort for these components must be made only once. Since the number of units for the same components increases considerably due to the modular construction, the costs for the different construction variants of the apparatus can be kept particularly low.

Background of the invention is that conventional devices for checking the tightness of tanks have a non-modular structure, so that for different construction variants always different components such as valves and pressure sensors must be installed. This results in high costs, which are particularly due to increased application costs for each vehicle series. These problems can be avoided by the device according to the invention.

The invention also includes a modular system for a plurality of construction variants of a device for checking the tightness of a tank for storing a fuel for an internal combustion engine, in particular a motor vehicle, with a connectable at least indirectly with an adsorption filter, in particular reversibly detachable connectable, and a first of the construction variants forming first Modular component, which comprises a pressure sensor for detecting a pressure in the tank, at least one flushing channel for guiding flushing air to the adsorption filter and at least one valve for fluidically blocking the flushing channel. The modular system further comprises a second module component, which comprises a pump for conveying air into the tank and can be reversibly detachably connected to the first module component to form a second of the construction variants. Advantageous embodiments of the device according to the invention are to be regarded as advantageous embodiments of the modular system according to the invention and vice versa.

In the modular system according to the invention, the first module component forms the first construction variant of the device, so that the first construction variant can be used, for example, for a first construction variant of the internal combustion engine. In this first construction variant of the internal combustion engine, therefore, no pump is provided and required for conveying air into the tank, since only the first module component, but not the second module component, is used for the first construction variant of the internal combustion engine.

To realize the second construction variant of the device, the second module component is connected to the first module component, so that the first module component, the second module component form the second construction variant. The second construction variant of the device can be used for a second construction variant of the internal combustion engine, wherein the second construction variant of the internal combustion engine is equipped with the air pump. This can be done in particular for countries where, in the context of an on-board diagnosis (OBD - On Board Diagnostic) to check the tightness of the tank by means of the pump. Through the use of modular components, a modular structure can be created, whereby the different variants of the device can be created in a simple and cost-effective manner, that is manufactured and assembled. It is possible to use the construction variants of the device with the same tank, so that a variant of the tank or the internal combustion engine can be realized in total only by omitting or adding the second module component.

Further advantages, features and details of the invention will become apparent from the following description of a preferred embodiment and from the drawing. The features and feature combinations mentioned above in the description as well as the features and feature combinations mentioned below in the description of the figures and / or shown alone in the figures can be used not only in the respectively specified combination but also in other combinations or in isolation, without the scope of To leave invention.

The drawing shows in:

1 a schematic representation of a device for checking the tightness of a tank for storing a fuel for an internal combustion engine, in particular a motor vehicle, with a first module component, which comprises a pressure sensor, a flushing passage and a valve, and with a second module component, which includes a pump for conveying comprises air and reversibly releasably connectable to the first module component; and

2 a further schematic representation of the device, wherein a diagnostic module is created by the reversibly releasably interconnected modular components.

In the figures, identical or functionally identical elements are provided with the same reference numerals.

1 shows in a schematic representation of a whole 10 designated device for checking the tightness of a tank 12 for storing a fuel in the form of a liquid fuel 14 , The liquid fuel 14 is used to operate an internal combustion engine of a motor vehicle, in particular a passenger car, and is in a through the tank 12 limited recording room 16 saved.

The Tank 12 has a filler neck 18 on, over which the tank 12 or the recording room 16 can be filled with liquid fuel. For the liquid fuel 14 These are, for example, gasoline or a diesel fuel, the liquid fuel 14 can outgas. By this is meant that in a part of the tank 12 in which the liquid fuel 14 not included is a gas from the liquid fuel 14 can collect. In particular, this gas comprises volatile fuel components from the liquid fuel 14 , wherein the volatile fuel constituents form fuel vapors. To cause a gas resulting from the outgassing, excessive pressure increase in the tank 12 to avoid is at least one vent line 20 provided over which the gas from the tank 12 can be dissipated. The vent line 20 on the one hand with the tank 12 and on the other hand with an adsorption filter in the form of an activated carbon filter 22 fluidly connected.

The activated carbon filter 22 serves to filter the fuel components from the gas, so that the gas after filtering it, for example, to the environment 24 of the tank 12 can be drained. Since the fuel components from the gas by means of the activated carbon filter 22 Filtered, excessive emissions of unburned hydrocarbons, that is, so-called HC emissions can be avoided.

By filtering out the fuel components of the activated carbon filter 22 in particular a filter material of this, increasingly loaded, whereby its capacity for unburned hydrocarbons or fuel components is reduced. To load the activated carbon filter 22 to reduce again, is the activated carbon filter 22 via a flushing line 26 connectable to the internal combustion engine. In the flushing line 26 is a valve 28 arranged, which between a the flushing line 26 fluidly occluding closed position and at least one the purge line 26 releasable open position is adjustable. The flushing line 26 is coupled to an intake tract of the internal combustion engine. In its operation, the internal combustion engine sucks in air. Is this the valve 28 open, so is the internal combustion engine air over the purge line 26 , the activated carbon filter 22 and a second purge line in the form of a scavenger passage 30 the device 10 from the environment 24 sucked in, the air also referred to as fresh air.

This suction and flow of fresh air through the flushing channel 30 , the activated carbon filter 22 and the flushing line 26 is in 1 by directional arrows 32 illustrated. The sucked air is by means of the flushing channel 30 to the activated carbon filter 22 guided and thus can the activated carbon filter 22 , in particular the filter material, flow through or flow around. This takes the activated carbon filter 22 flowing air in the activated carbon filter 22 containing fuel components with and transports the fuel components through the purge line 26 to the internal combustion engine and in particular in at least one combustion chamber of the internal combustion engine. In the combustion chamber, the fuel components from the activated carbon filter 22 burned, which can prevent excessive HC emissions.

The device 10 further comprises a pressure sensor 34 , by means of which a pressure in the tank 12 is detectable. Furthermore, the device comprises 10 a valve 36 , by means of which the flushing channel 30 is fluidic lockable. This means that the valve 36 between a flushing channel 30 fluidly occluded closed position and at least one of the flushing channel 30 releasable open position is adjustable. Therefore, the valve becomes 36 Also referred to as a shut-off valve or shut-off valve, wherein the valve 36 is preferably designed as a solenoid valve. Furthermore, the device comprises 10 a pump 38 comprising a motor M and at least one pump element 40 includes that is driven by the motor M. The motor M is preferably an electric motor. Will the pump element 40 powered by the motor M, so sucks the pump 38 Air, which by means of the pump 38 in the tank 12 can be promoted. This can increase the tightness of the tank 12 be checked. In this case, the device comprises 10 a suction line 42 over which the air from the pump 38 is sucked. This suction line 42 is therefore with a suction side of the pump 38 connected. Furthermore, the device 10 a pressure line 44 on which with a pressure side of the pump 38 connected is. The air is pumped 38 sucked on the suction side and conveyed to the pressure side, so that the air finally on the pressure lines 44 to the tank 12 is encouraged. It is in the pressure line 44 a valve in the form of a check valve 45 arranged to prevent unwanted backflow of air to the pump 38 to avoid.

To order a particularly simple, time-consuming and cost-effective installation of the device 10 To realize, is a first modular component in the form of a basic module 46 provided, which the pressure sensor 34 , the flushing channel 30 and the valve 36 comprises and at least indirectly fluidly connectable to the adsorption filter. Here is the basic module 46 a first assembly or a first assembly, which is independent of the tank 12 and the activated carbon filter 22 producible or mountable and reversibly detachable, that is non-destructively detachable, with the activated carbon filter 22 is connectable. This means, for example, that the tank 12 and the activated carbon filter 22 as well as the basic module 46 can be made independently and in particular at the same time. After making the activated carbon filter 22 can the basic module 46 to the activated carbon filter 22 grown as well as be solved by this.

Out 1 it can be seen that further upstream of the valve 36 arranged filter 48 is provided, by means of which the sucked and the flushing channel 30 filtered air is filtered.

In addition, a second module component in the form of a pump module 50 provided which the pump 38 , the suction line 42 , the pressure line 44 and the check valve 45 includes and reversibly detachable with the first module component (basic module 46 ), in particular fluidly connectable, is. The pump module 50 is an air pump module because the pump 38 is designed as an air pump. Further, the pump module 50 a second assembly or a second unit, which is independent of the basic module 46 , from the tank 12 and the activated carbon filter 22 can be produced or assembled. The pump module 50 can be reversibly detachable and therefore needs-based with the basic module 46 connected and solved by this.

If it is provided, for example, the internal combustion engine or the associated vehicle according to a first construction variant of the motor vehicle or the internal combustion engine only with the basic module 46 but not with the pump module 50 equip, so only the basic module 46 installed.

However, it is provided in a second construction variant of the internal combustion engine or the motor vehicle, the motor vehicle or the internal combustion engine both with the basic module 46 as well as with the pump module 50 equip, so the pump module 50 easy with the basic module 46 connected so that then the pump module 50 via the basic module 46 with the activated carbon filter 22 connected is.

In the first construction variant and in the second construction variant, the pressure sensor 34 over the activated carbon filter 22 with the tank 12 , especially the recording room 16 , fluidly connected, so that in the tank 12 or in the recording room 16 prevailing pressure over the activated carbon filter 22 by means of the pressure sensor 34 can be detected.

In the second construction variant, the suction line 42 upstream of the valve 36 fluidic with the flushing channel 30 connected. For example, the tightness of the tank 12 checked, then the pump 38 operated. Further, the valve 36 in a Closed position. The pump sucks 38 over the flushing channel 30 and the suction line 42 Air from the environment 24 at. The sucked air flows over the pump 38 , the pressure line 44 , the activated carbon filter 22 and the vent line 20 in the recording room 16 or the tank 12 , Further, by means of the pressure sensor 34 the one in the tank 12 prevailing pressure determined, so that by means of the pressure sensor 34 determined pressure the tightness of the tank 12 can be checked.

In particular, it is thus possible to reliably detect large leaks and holes with 0.5 mm and 1.0 mm diameter. As the flushing channel 30 by means of the valve 36 fluidly obstructed, the tank becomes the environment 24 or to the ambient air through the valve 36 closed, and by means of the pump 38 in the tank 12 conveyed air can not through the flushing channel 30 again to the environment 24 escape.

For example, it is provided that the pump 38 the tank 12 filled with a specified or specifiable pressure, for example in a range of 1 to 1000 hPa. Usually the tank 12 filled with a pressure of 50 hPa. By means of the pressure sensor 34 is it possible to control the pressure inside the tank 12 to measure directly. As a result, a pressure gradient can be determined, via which it can then be determined whether the tank 12 is leaking or leaking. This evaluation is carried out for example by means of a control unit.

By direct pressure measurement with the help of the pressure sensor 34 All environment variables can be taken into account and possibly excluded. For example, the outgassing of the fuel 14 be directly determined. The pump 38 can be particularly simple in construction, since no special requirements are placed on the accuracy of their power consumption. Furthermore, it is possible to use the respective components of the device 10 To design particularly inexpensive and high robustness of the device 10 to realize. By the direct pressure measurement, it is not necessary to check the tightness test on the current consumption of the motor M, that is on the so-called pump current, so that the tightness can be determined very accurately.

Out 2 is recognizable that through the basic module 46 and that with the basic module 46 reversibly releasably connected pump module 50 a diagnostic module 52 is formed or can be formed. Thus, it is possible, the interconnected modular components, that is, the diagnostic module 52 to handle as a whole in a simple manner, so that not the respective individual components of the device 10 must be handled individually.

The basic module 46 For example, includes a housing to which the pressure sensor 34 , the valve 36 and the flushing channel 30 are arranged. When connecting the pump module 50 with the basic module 46 it is conceivable the pump 38 in the housing of the basic module 46 to arrange. Alternatively, it is conceivable that the pump 38 to arrange outside of the housing.

LIST OF REFERENCE NUMBERS

10

contraption

12

tank

14

liquid fuel

16

accommodation space

18

Tankstutzen

20

vent line

22

Activated carbon filter

24

Surroundings

26

flushing line

28

Valve

30

irrigation channel

32

arrow

34

pressure sensor

36

Valve

38

pump

40

pump element

42

suction

44

pressure line

45

check valve

46

basic module

48

filter

50

pump module

52

diagnostic module

M

engine

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 19709903 A1 [0002]
• DE 102013216998 A1 [0006]

Claims (4)

Contraption ( 10 ) for checking the tightness of a tank ( 12 ) for storing a fuel ( 14 ) for an internal combustion engine, with at least one pressure sensor ( 34 ) for detecting a pressure in the tank ( 12 ), with at least one flushing channel ( 30 ) for guiding scavenging air to an adsorption filter ( 22 ) for filtering fuel components from gas from the tank ( 12 ), with at least one valve ( 36 ) for fluidic blocking of the flushing line ( 30 ) and with a pump ( 38 ) for conveying air into the tank ( 12 ), characterized in that at least indirectly with the adsorption filter ( 22 ) fluidically connectable and the pressure sensor ( 34 ), the flushing channel ( 30 ) and the valve ( 36 ) comprehensive first modular component ( 46 ) and a pump ( 38 ), second module component ( 50 ) are provided, which is reversibly detachable with the first module component ( 46 ) is connectable. Contraption ( 10 ) according to claim 1, characterized in that by the modular components ( 46 . 50 ) a diagnostic module ( 52 ) is formed. Contraption ( 10 ) according to claim 1 or 2, characterized in that the flushing channel ( 30 ) to the environment of the first module component ( 46 ) opens. Modular system for several construction variants of a device ( 10 ) for checking the tightness of a tank ( 12 ) for storing a fuel for an internal combustion engine, with at least indirectly with an adsorption filter ( 22 ) for filtering fuel components from gas from the tank ( 12 ) fluidly connectable and a first of the construction variants forming first modular component ( 46 ), which is a pressure sensor ( 34 ) for detecting a pressure in the tank ( 12 ), at least one flushing channel ( 30 ) for guiding scavenging air to the adsorption filter ( 22 ) and at least one valve ( 36 ) for fluidic blocking of the flushing channel ( 30 ), and with a second module component ( 50 ), which is a pump ( 38 ) for conveying air into the tank ( 12 ) and with the formation of a second of the construction variants reversibly detachable with the first module component ( 46 ) is connectable.

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