EP2333291B1 - Fuel tank - Google Patents

Description

The invention relates to a fuel tank having a connecting line from a filter element to a fresh air filter, according to the preamble of claim 1.

Typically, fuel tanks have a plurality of conduits, such as a fill line, a vent line, and the connecting line from the filter element to the fresh air filter, to name just a few examples. Such fuel tanks with the associated line system are well known, which is why will not be discussed in detail here.

The US 2004/0173013 A1 deals with a leak test device for a fuel vapor venting system. By means of a pump, the system is pressurized or expanded by an air flow path. The leak detection apparatus includes a motor unit that drives the pump to apply or reduce pressure, and an onboard power supply and a voltage control circuit. The voltage control circuit controls a battery voltage from the vehicle internal power supply to a predetermined voltage and supplies power to the motor unit. Further, the voltage control circuit is disposed in an air inlet passage or an air outlet passage. The air is introduced into the engine through the air intake passage. The fuel vapor venting system prevents fuel vapor generated in a tank from being emitted into the atmosphere. The fuel vapor is temporarily adsorbed in an adsorption filter and retained in the fuel vapor venting system. In a predetermined operating state of the internal combustion engine, the fuel vapor is supplied thereto. A movable member may be placed with its abutting portion on a valve seat which is formed at the end of a valve connection flow path on the side of a valve chamber. When the abutting portion is set against the valve seat, an air flow path and an open flow path are connected to each other, and further the air flow path and the open flow path and the valve connection flow path are separated from each other. The moving part is electromagnetically driven by a control unit energizing a coil so that an electromagnetic force acts on a core which pulls the movable upwards.

The US2006 / 0016253 A1 also deals with a leak test device for a fuel vapor venting system. The leak detection apparatus includes an electric pump having a motor driven pumping unit which is driven to pressurize or reduce pressure from the engine. The pump creates a pressure difference between the inner and the outer of the venting device. The leak detection device further comprises a speed control device which controls the engine speed to a predetermined speed. Next discloses the US 2006/0016253 A1 a control unit which energizes a coil so that an electromagnetic force is generated. This causes a displacement of a base body along the shaft upwards so as to be able to connect a connecting line through a valve seat with a pumping line. At the same time, a connection of a tank line through the valve seat is isolated from the atmosphere line, ie separated. Thus, an air flow from the container to the atmosphere, so the environment is interrupted.

The EP 1 510 804 A1 deals with a method and apparatus for leak diagnosis in a container. The leak diagnostic device includes means of reference drive current of an electric pump when air is pumped by the electric pump through a reference port. The apparatus further has means for diagnosing the presence of a steam leak by interrogating a minimum and subsequent values for the drive current of an electric pump when air is pumped by means of the electric pump in bypass to the reference opening in the container to be tested. Further, the apparatus comprises means for calculating a relative drive current, the reference current and the minimum drive current, and an area ratio and means for comparing the area ratio with a reference level when at least one predetermined state is reached to detect the presence of a leak.

The filter element is designed for example as an activated carbon filter, and z. B. hydrocarbons from fuel gases, so that they can not get into the environment. For this purpose, the filter element is arranged by way of example between the fuel tank and the fresh air filter of the internal combustion engine.

A fuel tank with associated piping system is z. B. in the US Pat. No. 7,481,101 B1 disclosed. Between a charcoal filter and the atmosphere, a negative pressure generating pump module is arranged, which has a switching valve and a bypass. In the switching valve bores are introduced. In a state referred to as "OFF State", the environment communicates via one of the bores with the input side of the activated carbon filter. In the case of an "on state", however, the activated charcoal filter communicates via the other bore with a pump side. Thus, a closed system is disclosed whether the on-off valve is in its OFF state or on-state.

In the US 5,651,349 also deals with a fuel tank with associated piping system, in particular deals with US 5,651,349 with a method for monitoring a venting system and with the venting system itself. An activated carbon filter communicates with the fuel tank on the one hand and with the internal combustion engine on the other hand. On the activated carbon filter, a valve is arranged to allow air into the activated carbon filter can.

The fuel tank or the corresponding system is subjected in particular after completion of the entire motor vehicle a leak test. This is the so-called "end of line test" included, so part of the final acceptance of the motor vehicle by the manufacturer. When checking the fuel tank with the (line) system connected to it, the connecting line is disconnected from the filter element. With the filter element, an external pressure generating means is connected, so that a corresponding pressure test is carried out, which indicates whether the fuel tank or the corresponding line system leaks, so leaks. Such a pressure test is well known. If no leaks are detected, the should Connecting line are reconnected to the filter element, so that only filtered fresh air can get into the fuel tank.

Despite the established and practiced quality assurance systems in the automotive industry, however, it may happen that due to human error, the connecting line is not reconnected to the filter element after successful completion of the pressure test. In such a case, in a normal operation of the motor vehicle or the internal combustion engine unfiltered fresh air could pass through the filter element in the fuel tank. For example, so liquids or solids could get into the fuel tank, since the connection to the fresh air filter does not exist. Of course, such impurities are considered to be particularly harmful.

The invention is therefore based on the object with simple means to improve a fuel tank of the input so that even after performing his pressure test always a connection of the filter element to the fresh air filter without special measures is ensured.

According to the invention the object is achieved by a fuel tank with the features of claim 1, wherein a diagnosis valve between the filter element and the fresh air filter is arranged, which has a passage, which forms a passage for operating gases in an operating position, and having a diagnostic channel which in a diagnostic position is connected to an external pressure generating means, and forms a diagnostic passage to the filter element in the diagnosis position.

It is essential that the diagnostic valve is mounted not only for a so-called "end of line test" extra between the filter element and the fresh air filter. With the invention, the diagnostic valve is constantly, so permanently disposed between the filter element and the fresh air filter, and is mounted before the pressure test, and not removed after the pressure test. This ensures that the connection line no longer has to be released from the filter element in order to carry out a pressure test, which is why it is advantageously ensured that fresh air, which is always flowing through the fresh air filter and filtered into it, enters the fuel tank arrives. A further advantage is that by means of the constantly arranged or mounted diagnostic valve, if necessary, a pressure test can be carried out by simply an external pressure generating means is connected to the diagnostic valve. For example, a leak test to be performed after the "end of line test" may be required if appropriate monitoring devices indicate malfunctions and / or leaks. Such a pressure test could be carried out in appropriately equipped workshops.

It is expedient for the purposes of the invention if the diagnostic valve has connecting elements which can be connected in a medium-tight manner to a filter side and to a fresh air filter side of the connecting line. Of course, the diagnostic valve can be connected with one of its connecting elements directly either with a corresponding output of the fresh air filter or with a corresponding input (based on the flow direction of the fresh air) of the filter element.

In an advantageous embodiment, the connecting elements are designed as a plug-in socket, which is adapted with its outer circumference to the corresponding inner circumference of either the connecting line or the other component, depending on where the diagnostic valve is arranged.

Thus, the diagnosis valve in a simple configuration can be easily connected via a connector medium-tight with the corresponding components permanently, but intentionally detachable. Of course, even reinforcing elements, for example in the embodiment may be provided as a screw clamp to permanently, but intentionally releasably ensure the respective medium-tight connection.

It is expedient for the purposes of the invention if the diagnostic valve has a basic body which can be transferred from the operating position to the diagnosis position in a housing. In the respective position of the base body is kept stable position. The main body is seen in a preferred embodiment in longitudinal section cylindrical, preferably designed as a solid body, wherein the diagnostic channel and the passage are introduced according to the invention in the body.

In an embodiment according to the invention, the main body has a foot side and a head side opposite thereto. Between the head side and an end wall of the housing according to the invention an energy storage, arranged in the embodiment as a spring element. At the foot side a connection extension is arranged, which projects beyond the housing foot.

In the operating position, the through-channel is arranged in alignment with the two connecting elements or with the passage openings arranged in each case. In a preferred embodiment, the through-channel can be introduced rectilinearly, that is to say transversely to a central axis, in the base body. This is useful if the respectively opposite connecting elements are arranged on a common height to the housing. It is also conceivable, however, to arrange the mutually opposite connecting elements relative to one another at different heights, that is to say in the vertical direction, offset relative to one another. In such an embodiment, it is expedient if the passage has a correspondingly inclined course to form the passage for operating gases.

To perform a pressure test, the terminal extension is connected to the external pressure generating means. For this purpose, a plug-on end of a suitable line element can be plugged onto the connection extension. In this case, the base body is moved against the force of the force accumulator into the interior of the housing from the operating position to the diagnosis position. If the base body has reached the diagnosis position, a secure fixing of the base body in the diagnosis position is achieved by suitable means. For this purpose, a holding element may be provided on the line element, which cooperates with a retaining ring arranged on the housing, and holds the base body in a positionally stable manner against the force of the force accumulator or against the spring force acting in the diagnosis position. On the connection extension, on the outside, seat-reinforcing elements can also be arranged, which correspond with them accordingly cooperating counter-elements cooperate on the Aufsteckende. Also, the retaining ring may have on its surface grooves or the like to form quasi detent positions for the holding element or its acting holding area.

The diagnostic channel has two sections, from which an introduction section merges into a lead-out section. The introduction section is arranged parallel to a central axis of the main body or of the diagnosis valve in the center thereof. The discharge section adjoins the introduction section at an acute angle relative to the central axis, for example, and leads to an outer circumference of the main body. In contrast, the introduction section is guided out of the main body into the connection extension and opens into the operating position to the environment.

The diagnostic channel is designed so that a contact or a connection to one of the connecting elements is avoided in the operating position. Only when the main body is in the diagnosis position, the diagnostic channel is connected to the filter element oriented to the connecting element or with its passage opening in connection.

If the external pressure generating means connected to the diagnostic valve or with the arranged on the body connecting piece, a pressure test can be carried out in a known manner.

When the pressure test or the pressure test has been completed, the push-on end is removed from the connecting piece, as a result of which the basic body is returned to the operating position by a relaxation of the force-storing element or, as a result of the spring force. In order to achieve that the base body is transferred exactly to its operating position, movement limiting elements are provided, which are arranged on the foot side of the housing, and something in the inner, so in the direction of the central axis projecting into this, so that a Auflagerstufe is formed, on which the main body hangs up on the foot. In a favorable embodiment, the support step is arranged on the retaining ring, so that this advantageously has a dual function. On the one hand, the retaining ring serves to secure the base body in the diagnosis position. On the other hand, the retaining ring with his arranged Auflagerstufe as an abutment for the body in its operating position.

To seal the base both in the operating position and in the diagnostic position with its outer circumference to the inner circumference of the housing circumferential grooves are provided on the base body, in which sealing elements, for. B. are inserted as an O-ring seal, which abut with its outer sealing surface on the inner circumference of the housing. For example, a plurality of sealing elements (and grooves) are provided, which are arranged so that the respective opposite connecting elements or their through holes are sealed in the operating position and on the other in the diagnostic position each of two vertically spaced from each other in the vertical direction sealing elements. The respective passage opening is therefore arranged in the vertical direction between the two sealing elements.

With the invention it is achieved that a pressure test can be carried out without the connecting line having to be drawn off from the filter element, which is preferably designed as an activated charcoal filter, since the diagnosis valve is permanently mounted. This ensures that a reconnection can be omitted, so that it can be ensured without special measures that always fresh air flowed through the fresh air filter and filtered there passes into the fuel tank or its line system, whereby contamination is avoided.

Fig. 1

ein Diagnoseventil in einem Längsschnitt in seiner Betriebsposition, und

Fig. 2

das Diagnoseventil aus Figur 1 in seiner Diagnoseposition.

Further advantageous embodiments of the invention are disclosed in the subclaims and the following description of the figures. Show it

Fig. 1

a diagnostic valve in a longitudinal section in its operating position, and

Fig. 2

the diagnostic valve off FIG. 1 in his diagnostic position.

In the different figures, the same parts are always provided with the same reference numerals, so that these are usually described only once.

FIG. 1 time a diagnostic valve 1. The diagnostic valve 1 is arranged for example in a connecting line 2, which extends from a fresh air filter, not shown, to a filter element, not shown, wherein the filter element is preferably designed as an activated carbon filter.

By way of example, the connection line 2 leading in the drawing plane on the left side of the diagnosis valve 1 leads to the fresh air filter, the opposite (right) side leading to the filter element.

The components mentioned are part of a fuel tank or its conduit system of a motor vehicle with an internal combustion engine. With the diagnostic valve 1, a pressure test of the fuel tank or the associated system, for example, in the context of a so-called "end of line tests" are performed. The diagnostic valve 1 is advantageously permanently mounted, and will not be removed after the pressure test.

The diagnostic valve 1 has a housing 3, in which a base body 4 is arranged. The housing 3 has in the longitudinal section shown a U-shaped configuration with a top web 5 and two U-legs 6, 7. On the foot side, ie opposite the head bar 4, the housing 3 is opened.

The head bar 5 can also be referred to as head side 5.

The U-leg 6 is arranged on the fresh air filter side of the diagnostic valve 1, wherein the U-leg 7 is oriented to the filter element side. Fresh air filter side, a first connecting element 8 is arranged on the U-leg 6, wherein on the opposite filter element side, a second connecting element 9 is arranged. The two connecting elements 8 and 9 are exemplified as Einsteckstutzen 8 and 9, on which the connecting line 2 is attached with the corresponding section medium-tight. The in the FIGS. 1 and 2 identifiable gaps are exaggerated, and absent in practice.

The connecting elements 8 and 9 are arranged offset in height in a direction indicated in the drawing plane vertical direction (arrow 11) to each other, which means that the connecting element 9 relative to the head side 4 is arranged lower than the connecting element eighth

On the foot side, a retaining ring 12 is arranged on the housing 3, which projects beyond the housing wall both in the direction of a central axis X and away from it, so that on the outside a holding surface 13 and on the inside a support step 14 is formed.

In the base body 4, which is exemplified as a cylindrical solid body, a through-channel 16 and a diagnostic channel 17 are arranged. On the foot side, the main body has an Anschlussfortsatz 18, which has a smaller diameter than the base body 4. At the head end of the body 5 is a force storage 19, arranged in the embodiment as a spring element. The energy accumulator 19 or the spring element is connected on the other side to the top web 5 of the housing 3.

At the in FIG. 1 illustrated embodiment, the diagnostic valve is shown in its operating position 21. The passage 16 is arranged so that in the operating position 21, a connection from the fresh air filter side (first) connecting element 8 to the filter element side (second) connecting element 9, ie a passage 22 is formed for operating gases. Operating gases are, for example, filtered fresh air and fuel gases. Since both connecting elements 8 and 9 are arranged offset in height to one another, the passage channel 16 in the illustrated sectional view relative to the central axis X corresponding to the head side 5 in the direction of the foot side running obliquely.

The diagnostic channel 17 has two sections 23 and 24, namely an introduction section 23, which merges into a discharge section 24. The introduction section 23 is guided parallel to the central axis X extending through the connection extension 18 into the base body 4. With its central axis X1 of the introduction section 23 is congruent to the central axis X, ie centrally inserted into the diagnostic valve 1 and its base body 4. The introductory section 23 opens foot side, so on the free end face 26 of the connection extension 18 to the environment when the diagnostic valve 1 is arranged in the operating position.

The discharge section 24 is arranged at an angle relative to the center axis X, preferably at an acute angle to the introduction section 23, and opens with its mouth opening 27 on an outer circumference of the main body 4.

On the outer circumference of the base body 4 circumferential grooves 28 are introduced, in each of which a sealing element 29 is inserted, which applies sealingly both on the groove bottom and on the inner wall of the housing 2. By way of example, three grooves 28 each having a sealing element 29 are provided.

Seat reinforcing elements 31, for example grooves or tooth-like latching elements, which cooperate with corresponding counter-scores or counter-latching elements on a push-on end of a line section for connecting the connection extension 18 to an external pressure-generating element, can be arranged on the outer circumference of the connection extension 18. At the Aufsteckende also holding elements may be arranged, which cooperate with the retaining ring 12 and with its holding surface 13 to the base body 4 in the in FIG. 2 to keep the diagnosis position 32 shown.

In the diagnosis position 32, the base body 4 is displaced against the force of the force accumulator 19 to the head side 5 of the housing 2 so that the diagnostic channel 17 with its discharge section 24 or with its mouth opening 27 in conjunction with the filter element side (second) connecting element 9 occurs. Thus, connection is made from the external pressure generating means via the diagnostic channel 17 to the filter element and so on, so that a pressure test can be performed. In the diagnosis position 32, the through-channel 16, as shown, no longer has any connection neither to the connecting element 8 nor to the second connecting element 9 or to its passage openings.

The diagnostic position 32 is held by means of the above-exemplified elements or components until the pressure test is completed. Of course you can too other than the components mentioned cause a determination of the diagnostic position.

Like that FIGS. 1 and 2 can be seen, the grooves 28 and sealing elements 29 are arranged so that the through holes are surrounded in the connecting elements 8 and 9 in one of the respective positions 21 and 32 of two vertically adjacent sealing elements 29, so that either a diagnostic sealing region 33 or a Operating sealing area 34 is formed. In the diagnosis position 32, the foot side of the main body 4 or its free end face is guided with the attachment extension 18 arranged thereon into the interior of the housing 2.

If the push-on is removed from the attachment extension 18, the base body 4 is removed from the diagnosis position 32 due to the force stored in the force store 19, ie, preferably by a release of the spring element into the operating position 21 (FIG. FIG. 1 ) returned. It is favorable that on the retaining ring 12, the support stage 14 is arranged, which serves as a kind of movement limiting element 14, and ensures that the base body 4 is stopped exactly in the necessary operating position 21 in its movement, so that the passageway 16 form the passage 22 can.

In the operating position 21, the diagnosis valve 1 can remain permanently arranged in the connecting line 2. It is favorable that so also pressure tests outside of the "end of line tests", ie z. B. can be performed with appropriate warnings during the life of the motor vehicle.

Claims (7)

1. Fuel tank, which has a connecting line (2) from a fresh air filter to a filter element between which a diagnostic valve (1) is arranged which has a basic body (4) which is arranged in a housing (3), characterized in that
   the basic body (4) has, on the base side, a connecting extension (18) which has a smaller diameter than the basic body (4), a stored-energy element (19) being arranged as spring element on the head side of the basic body (4), both an operating port (16) and a diagnostic port (17) being arranged in the basic body (4),
   and the operating port (16) in an operating position (21) forming a passage (22) for operating gases, and the diagnostic port (17) in a diagnostic position (32) being able to be connected to an external pressure-generating means and in the diagnostic position (32) forming a diagnostic passage to the filter element.
2. Fuel tank according to Claim 1,
   characterized in that
   the diagnostic valve (1) is permanently arranged between the fresh air filter and the filter element.
3. Fuel tank according to Claim 1 or 2,
   characterized in that
   the diagnostic valve (1) comprises connecting elements (8, 9), which serve for connecting the diagnostic valve (1) medium-tightly to the connecting line (2) and/or the fresh air filter and/or the filter element.
4. Fuel tank according to one of the preceding claims,
   characterized in that
   the diagnostic valve (1) comprises the stored-energy element (19), which in each case is arranged on the head side between its body (4) and its housing (2).
5. Fuel tank according to one of the preceding claims,
   characterized in that
   the diagnostic valve (1) comprises the connecting extension (18), to which the external pressure-generating means can be connected, the diagnostic port (17) being led through the connecting extension (18) and the body (4) to an outer circumference of the body (4).
6. Fuel tank according to one of the preceding claims,
   characterized in that
   the diagnostic valve (1) or its body (4) is fixed in its diagnostic position (32).
7. Fuel tank according to one of the preceding claims,
   characterized in that
   the diagnostic port (17) comprises an inlet section (23) and an outlet section (24), which in the diagnostic position (32) is connected to the filter element.

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