Tank arrangement with leak monitoring

Abstract

A tank arrangement for a motor vehicle, comprising a tank having a filling nozzle (1) for filling the tank (1) and a tank closure (2) which can be placed on the filling nozzle (1) and which can be closed on the filling nozzle (1), the tank arrangement comprising a VLD unit (vacuum leak detection), the VLD unit is configured to identify an insufficient tightness of the tank by monitoring a reduced pressure in the tank, where the tank closure (2) comprises a sealing element (3) that seals with respect to the filling nozzle (1) when the tank closure (2) is closed on the filling nozzle (1), where the tank closure (2) comprises a spacer element (4) that is configured to separate the tank closure (2) from the filling nozzle (1) when the tank closure (2) is closed on the filling nozzle (1). The spacer element (4) is placed on the filling nozzle (1) on the tank closure (2) and thereby prevents the sealing element (3) from coming into contact with the filling nozzle (1) such that there is no sealing between the tank closure (2) and the filling nozzle (1) when the tank closure (2) comes into contact with the filling nozzle (1).

Description

TECHNICAL FIELD

[0001] The present invention relates to a tank arrangement for a motor vehicle. BACKGROUND

[0002] Tank arrangements are known for use in motor vehicles in order to, for example, guide fuel required for driving the motor vehicle, for example gasoline or diesel, in a tank in the motor vehicle, for example, for an internal combustion engine as drive motor.

[0003] Tank systems using VLD units (vacuum leak detection or diagnosis), for example NVLD units ("natural vacuum leak detection" units), are known in order to use the reduced pressure that is usually produced in the tank when the fuel is cooled, for example when the vehicle is stopped, in order to identify a non-sealing of the tank and thus a leak.

[0004] For example, DE 102012212109 A1 discloses a tank ventilation system of a motor vehicle, which is provided with an internal combustion engine, which comprises an NVLD unit ("natural vacuum leak detection" unit) with a diaphragm valve unit by means of which, after the vehicle has been parked, the sufficient sealing of the tank system is checked by forming a reduced pressure in the tank system, which is blocked in an appropriate manner with respect to the monitored environment, which contains an intermediate reservoir that can be cleaned by means of a cleaning line that is opened in the intake passage of the internal combustion engine, from which volatile hydrocarbons are discharged from the tank, wherein a bypass line is provided, which bridges or bypasses the NVLD unit with a blocking valve, which is arranged between the tank system and the environment. Via the bypass line, ambient air can reach the intermediate reservoir with an open blocking valve, which is closed in an appropriately controlled manner when the vehicle is parked and opened at least during the cleaning operation of the intermediate reservoir.

[0005] When a tank closure is only placed on the filling spout of the tank, for example after the tank has been filled, but is not closed or not properly closed, an incorrect situation exists, which should also be identified by the tank system. However, a tank closure placed in this way is usually not identified as a leak by the VLD unit. SUMMARY

[0006] It is an object of the present invention to provide a tank arrangement for a motor vehicle, which can identify a tank closure that is only placed in position and not closed.

[0007] This object is achieved by a tank device for a motor vehicle, comprising a tank having a filling spout for filling the tank and a tank closure which can be placed on the filling spout and can close on the filling spout, wherein the tank device comprises a VLD unit (vacuum leak detection) which is configured to identify an insufficient tightness of the tank by monitoring a reduced pressure in the tank, wherein the tank closure comprises a sealing element which seals against the filling spout when the tank closure is closed on the filling spout, wherein the tank closure comprises a spacing element which bears on the filling spout and thereby prevents the sealing element from coming into contact with the filling spout when the tank closure is placed on the filling spout and is not closed, so that there is no tightness between the tank closure and the filling spout.

[0008] Due to the fact that the sealing element of the tank closure which is not closed does not come into contact with the filling spout, the tank closure is not pulled towards the filling spout by means of the reduced pressure which is generated in the tank, and a leak is identified by the VLD unit.

[0009] According to the application, it has been determined that the reduced pressure which is generated in the tank is generally sufficient to pull a tank closure which has been placed on the filling spout of the tank but has not been properly closed, so that the VLD unit detects the expected reduced pressure but cannot identify any leak.

[0010] According to the application, the tank closure is therefore provided with at least one spacing element, in particular at least one resilient element, which bears on the filling spout when the tank closure has been placed on the filling spout and is not closed, thereby preventing the sealing element from coming into contact with the filling spout. The spacing element preferably prevents the sealing element from moving axially closer to the filling spout. The tank closure is then not pulled against the filling spout by the reduced pressure in the tank, and a non-leaking tightness can be identified by the VLD unit, for example an NVLD unit (natural vacuum leak detection).

[0011] If the tank closure is closed on the filling spout, the at least one spacing element is deactivated by the closure, in particular by screwing, in particular by displacement of the position of the spacing element, so that the sealing element seals the filling spout when the tank closure is closed on the filling spout.

[0012] Further refinements of the application are set out in the dependent claims, the description and the drawings.

[0013] Preferably, the spacing element is a resilient element against which the sealing element comes into contact with the filling spout when the tank closure is closed on the filling spout.

[0014] Preferably, the tank closure and / or the filling spout have a thread, so that the tank closure can be closed on the filling spout by screwing.

[0015] The spacing element, preferably the resilient element, can be formed from spring steel.

[0016] Preferably, the tank closure comprises a plurality of spacing elements, preferably resilient elements, which are arranged on the tank closure circumferentially around the opening of the filling spout when the tank closure has been placed, that is to say at least two spacing elements.

[0017] The individual spacing elements can extend, for example, at least partially in the circumferential direction of the opening of the filling spout.

[0018] The spacing elements can project from the tank closure in the direction towards the filling spout.

[0019] The spacing elements can have a radial outward curvature or bend relative to the opening of the filling spout, which causes a radial outward movement of the spacing elements when the tank closure axially approaches the configuration, in particular the shoulder, of the filling spout in the direction towards the filling spout.

[0020] When the tank closure is placed on the filling spout and not closed, the spacing elements are preferably supported on the filling spout on the shoulder of the filling spout, so that when the tank closure is closed the spacing elements are pressed radially outward relative to the opening of the filling spout, so that the sealing element comes into contact with the filling spout and seals relative to the filling spout.

[0021] Preferably, the sealing element is a ring seal which extends around the opening of the filling spout when the tank closure is placed.

[0022] Preferably, the tank device comprises no additional sealing elements which seal between the tank closure and the filling spout in addition to the sealing element.

[0023] If the tank device comprises at least one additional sealing element, each additional sealing element seals relative to the filling spout when the tank closure is closed on the filling spout, each additional sealing element is arranged so that the additional sealing element does not seal between the tank closure and the filling spout when the tank closure is placed on the filling spout and not closed, so that there is no sealing between the tank closure and the filling spout. BRIEF DESCRIPTION OF DRAWINGS

[0024] The application will be described below by way of example with reference to the accompanying drawings.

[0025] Figure 1 A cutaway cross-sectional view of a tank device for a motor vehicle is shown, and the position of the area A is shown.

[0026] Figure 2 A cutaway cross-sectional view of a tank device for a motor vehicle is shown, and the position of the area A is shown. Figure 1Cross-sectional view of area A according to the application in a tank arrangement according to the application, wherein the tank closure is placed and not closed.

[0027] Figure 3 Cross-sectional view of area A according to the application in a tank arrangement according to the application, wherein the tank closure is placed and not closed. Figure 1

[0028] Cross-sectional view of area A according to the application in a tank arrangement according to the application, wherein the tank closure is placed and not closed. Figure 4 Figure 3 Figure 1 Cross-sectional view of area A according to the application in a tank arrangement according to the application, wherein the tank closure is placed and not closed. DETAILED DESCRIPTION

[0029] Figure 1 Cross-sectional view of a tank arrangement for a motor vehicle, which shows a filling spout 1 of a tank, while the tank is not shown in more detail. The filling spout 1 is closed by a tank closure 2. A sealing element 3, which extends around the circumference of the filling spout 1, acts between the tank closure 2 and the filling spout 1. In the area A, which is shown as a dashed rectangle in the figure, the sealing element 3 is shown in more detail. Figure 2 Figure 3 and Figure 4 The area A is shown in more detail in the figures Figure 1

[0030] In this case, Figure 2 Cross-sectional view of a tank arrangement according to the application, wherein the tank closure 2 is placed and not closed. The tank closure 2 comprises a circumferential sealing element 3. The sealing element 3 rests on a shoulder 6 of the filling spout 1 in the area B shown. The tank arrangement does not comprise any spacing element or resilient element, which would prevent the sealing element 3 from resting on the shoulder 6 when the tank closure is not closed. When a reduced pressure 7 occurs in the tank, that is to say a reduced pressure compared to the ambient pressure 8, the sealing element 3 is thus pulled inwards in the direction towards the filling spout 1 and the support of the sealing element 3 on the filling spout 1 is thus further strengthened. As a result, the not shown NVLD unit recognizes the expected reduced pressure and thus there is no problem in the tank system.

[0031] In contrast, Figure 3 Cross-sectional view of a tank arrangement according to the application, wherein the tank closure is placed and not closed.

[0032] The tank arrangement comprises an NVLD unit (natural vacuum leak detection), which is configured to recognize an insufficient tightness of the tank by monitoring a reduced pressure in the tank. The tank closure 2 comprises a sealing element 3, which extends around the opening of the filling spout 1 and which seals with respect to the filling spout 1 when the tank closure 2 is closed on the filling spout 1.

[0033] ​​​​According to the invention, the tank closure 2 comprises a spacer element 4, which bears on the filling nozzle 1 when the tank closure 2 is placed on the filling nozzle 1 and is not yet closed, and thereby prevents the sealing element 3 from coming into contact with the filling nozzle 1, so that the sealing element 3 is not pulled against the filling nozzle 1 by the reduced pressure in the tank and thus does not seal against the filling nozzle 1. This is shown in Figure 3 and in particular in the region B, which shows that the sealing element 3 lacks support on the filling nozzle 1, that is to say on the shoulder 6 of the filling nozzle 1.

[0034] The spacer element 4 or more, for example two spacer elements 4, are arranged on the tank closure 2 radially outside the sealing element 3.

[0035] The spacer element 4 is an elastic element against which the sealing element 3 comes into contact with the filling nozzle 1 when the tank closure 2 is closed on the filling nozzle 1. The closed state of the tank device from Figure 3 is shown in Figure 4 .

[0036] The tank closure 2 and / or the filling nozzle 1 have a thread 5, so that the tank closure 2 can be closed by screwing on the filling nozzle 1.

[0037] The spacer element 4, that is to say the elastic element, is formed from a spring steel sheet and projects axially from the tank closure 2 in the direction towards the filling nozzle 1. The spacer element 4 has a curvature or a bend radially outwards with respect to the opening of the filling nozzle 1, which lies against the shoulder 6 of the filling nozzle 1 when the tank closure 2 is placed and not yet closed (in the region A Figure 3 ) and performs a movement radially outwards of the spacer element 4 when the tank closure 2 axially approaches the configuration in the direction towards the filling nozzle 1, that is to say the shoulder 6 of the filling nozzle 1. As a result of the fact that the spacer element 4 is displaced outwards against its elastic force by means of the thread 5 and slides from the shoulder 6 of the filling nozzle 1 when the tank closure 2 is closed (in the region C Figure 3 ), the sealing element 3 can rest on the shoulder 6 and / or on other parts of the filling nozzle 1 and seal against the filling nozzle 1. Figure 4 .

[0038] The spacer element 4 thus bears on the shoulder 6 of the filling nozzle 1 in such a way when the tank closure 2 is placed on the filling nozzle 1 and not yet closed, that is to say radially outwards with respect to the opening of the filling nozzle 1, so that the spacer element 4 is pressed radially outwards with respect to the opening of the filling nozzle 1 when the tank closure 2 is closed, so that the sealing element 3 comes into contact with the filling nozzle 1 and seals against the filling nozzle 1.

[0039] The tank closure 2 can comprise a plurality of spacing elements 4, preferably elastic elements, which are arranged circumferentially on the tank closure 2 around the opening of the filling nozzle 1 when the tank closure 2 is placed and which are located on the filling nozzle 1 when the tank closure 2 is positioned, that is to say at least two spacing elements 4.

[0040] The sealing element 3 is an annular seal which extends around the opening of the filling nozzle 1 when the tank closure 2 is placed. The sealing element 3 can for example have a U-shaped profile.

[0041] List of reference signs

[0042] 1 filling nozzle

[0043] 2 tank closure

[0044] 3 sealing element

[0045] 4 spacing element

[0046] 5 thread

[0047] 6 shoulder

[0048] 7 vacuum

[0049] 8 ambient pressure

[0050] A region

[0051] B region

[0052] C region

Claims

1. A canister assembly for a motor vehicle, comprising a canister having a filling nozzle (1) for filling the canister (1) and a canister closure (2) that can be placed on the filling nozzle (1) and can be closed on the filling nozzle (1), wherein, The can assembly includes a vacuum leak detection unit, or VLD unit, which is configured to identify inadequate sealing of the can by monitoring reduced pressure in the can. The can closure (2) includes a sealing element (3) that seals relative to the filling nozzle (1) when the can closure (2) is closed on the filling nozzle (1). The can closure (2) also includes a spacer element (4) that supports the filling nozzle (1) when the can closure (2) is placed on the filling nozzle (1) and not closed, thereby preventing the sealing element (3) from contacting the filling nozzle (1) and resulting in no seal between the can closure (2) and the filling nozzle (1).

2. The tank apparatus according to claim 1, Its features are, The spacer element (4) is an elastic element, and when the can closure (2) is closed on the filling nozzle (1), the sealing element (3) overcomes the force of the elastic element and contacts the filling nozzle (1).

3. The tank apparatus according to claim 1, Its features are, The can closure (2) and / or the filling nozzle (1) have threads (5) such that the can closure (2) can be closed on the filling nozzle (1) by screwing.

4. The tank apparatus according to claim 1, Its features are, The can closure (2) includes a plurality of spacer elements (4), preferably elastic elements, which are arranged circumferentially around the opening of the filling nozzle (1) when the can closure (2) has been placed.

5. The tank apparatus according to claim 1, Its features are, The spacer element (4), preferably an elastic element, is formed of a spring steel plate.

6. The tank apparatus according to claim 1, Its features are, The spacer element (4) protrudes from the can closure (2) in the direction toward the filling nozzle (1) and has a curvature or bend that is radially outward relative to the opening of the filling nozzle (1). When the can closure (2) approaches the construction of the filling nozzle (1) in the direction toward the filling nozzle (1), particularly the shoulder (6), the curvature or bend causes the spacer element (4) to move radially outward.

7. The tank apparatus according to claim 1, Its features are, When the can closure (2) is placed on the filling nozzle (1) and not closed, the spacer element (4) is supported on the filling nozzle (1) on the shoulder (6) such that when the can closure (2) is closed, the spacer element (4) is pressed radially outward relative to the opening of the filling nozzle (1), such that the sealing element (3) contacts the filling nozzle (1) and seals relative to the filling nozzle (1).

8. The tank apparatus according to claim 1, Its features are, The sealing element (3) is an annular seal that extends around the opening of the filling nozzle (1) when the can closure (2) is placed.

9. The tank apparatus according to claim 1, Its features are, Apart from the sealing element (3), the can device does not include additional sealing elements that seal between the can closure (2) and the filling nozzle (1), or each additional sealing element seals relative to the filling nozzle (1) when the can closure (2) is closed on the filling nozzle (1), and when the can closure (2) is placed on the filling nozzle (1) and not closed, the additional sealing elements are arranged such that the additional sealing elements do not seal between the can closure (2) and the filling nozzle (1), so that there is no seal between the can closure (2) and the filling nozzle (1).

Images