Fuel system

Abstract

Relates to a tank system and a closure, comprising a base section and a membrane section, wherein the base section has a jacket-shaped wall section and a transition region adjacent thereto, wherein the membrane section borders the transition region and protrudes from the transition region along a central axis, wherein the membrane section is designed to be brought into a blocking state or into a permeable state, wherein the membrane section is substantially fluid-impermeable in the blocking state, and wherein the membrane section is fluid-permeable along the central axis in the permeable state.

Description

[0001] The present invention relates to a tank system, in particular for use in a motorhome or caravan, and to a closure for use in such a tank system.

[0002] It is already known from the prior art that a tank, in particular a fresh water tank of a motorhome or caravan, can have a ventilation and / or venting system to allow the air displaced by the introduced fluid to escape when the tank is filled with fluid, as well as to allow excess fluid to overflow. It is also known to allow ventilation of the tank, in particular to allow a sufficient flow of air into the tank when a large amount of fluid is withdrawn from the tank. For this purpose, so-called riser pipes are arranged and fixed in the tank in tank systems known from the prior art, which connect the interior of the tank with the environment. The problem here is that vermin or dirt particles can also get into the interior of the tank through these riser pipes, which severely impairs tank hygiene.To prevent such ingress of dirt particles or vermin, attempts have already been made to install a mechanical check valve in the riser pipe. However, this solution is complex to construct and therefore costly, and is also susceptible to contamination, as dirt particles can severely disrupt the function of the check valve.

[0003] It is therefore an object of the present invention to provide a tank system which is inexpensive and easy to manufacture and ensures a high level of safety and tightness of the tank interior against the penetration of unwanted dirt particles and fluid.

[0004] These objects are achieved by a closure according to claim 1 and a tank system according to claim 10. Further embodiments and preferred features of the invention can be found in the dependent claims.

[0005] According to the invention, a closure is provided, in particular for use in a tank, comprising a base section and a membrane section, wherein the base section has a jacket-shaped wall section and, adjacent thereto, a transition region, wherein the membrane section borders the transition region and protrudes from the transition region along a central axis, wherein the membrane section is designed to be brought into a blocking state or into a permeable state, wherein the membrane section is substantially fluid-impermeable in the blocking state, and wherein the membrane section is fluid-permeable along the central axis in the permeable state. The closure is provided and designed in particular for use in or on a riser pipe of a tank system and has a base section which has a jacket-shaped wall section and a transition region.The wall section is in particular designed with an outer surface adapted to the internal geometry of a riser pipe, such that the wall section can form a sealing contact with the inside of a riser pipe. In order to enable venting of the tank interior despite the sealing arrangement of the closure in the riser pipe, the closure has a membrane section which is designed such that it normally assumes a blocking state and can only be brought into a permeable state when a pressure difference is applied in a selected direction, in which state a fluid, preferably a gas, air or water, can flow through the closure to reach the outside of the tank. Put simply, the membrane section of the closure functions as a one-way valve, which only allows fluid exchange in one flow direction.A transition section is provided between the base section, which can be sealingly arranged in the riser pipe, and the membrane section, which in particular connects the different external geometries of the base section and the membrane section. The central axis is preferably an axis running centrally through the base section, the transition section, and the membrane section, which is preferably also the axis along which a fluid flow can flow through the membrane section. When the closure is inserted into a riser pipe, the central axis is preferably coaxial with the pipe axis of the riser pipe in the region of the closure.

[0006] In one embodiment, the wall section is substantially axially symmetrical and / or rotationally symmetrical about the central axis and preferably has a circular cross-section. A substantially axially symmetrical and / or rotationally symmetrical cross-sectional geometry is understood to mean, in particular, a square or circular outer shape of the wall section. Within the scope of the present invention, it is understood that the wall section is adapted to the internal geometry of the riser pipe in order to form a sealing connection there. The wall section preferably has an excess dimension compared to the internal geometry of the riser pipe such that the closure can be clamped in the riser pipe under elastic prestress. This ensures, on the one hand, a secure arrangement of the closure in the riser pipe and, on the other hand, a high level of tightness in the edge region of the closure.

[0007] In one embodiment, the transition section has a substantially V-shaped cross-section in a sectional plane running parallel to the central axis, which tapers towards the membrane section. The V-shaped cross-section of the transition section is particularly material-saving and connects the axially or rotationally symmetrical wall section with the substantially flat membrane section. At the same time, the V-shaped transition section ensures that if fluid collects in the base section, it can reliably flow away toward the membrane section, provided there is sufficient overpressure in the tank.

[0008] In one embodiment, at least the membrane section is formed from an elastically deformable material with a Shore hardness of 20 to 90 Shore A, preferably 50 to 70 Shore A. LSR (liquid silicone rubber) is particularly preferably used as the manufacturing material for at least the membrane section. The very low Shore hardness of this material enables particularly easy elastic deformation of the membrane section. Alternatively or additionally, this good deformability is also achieved by thin walls in the area of the membrane section. In this way, the membrane section can be brought into its permeable state with only a relatively low overpressure in the tank. Furthermore, LSR exhibits very good permanent elasticity and is approved for drinking water systems.Particularly preferably, the entire closure, i.e., all areas such as the base section and the membrane section or a preferably present collar, are formed integrally from the same manufacturing material. In an alternative embodiment, the membrane section can be formed from a softer material than the base section and the transition section using a coextrusion process or two-component casting process.

[0009] In one embodiment, the membrane section has a first membrane wall and a second membrane wall opposite the first membrane wall, wherein the first and second membrane walls bear against one another substantially over their entire surface in the blocking state, and wherein a gap is formed between the first membrane wall and the second membrane wall in the permeable state, which gap is fluid-permeable along or parallel to the central axis. The membrane walls are two flat, tab-like regions of the membrane section, which are preferably connected to one another at their respective lateral ends by common corner regions. In other words, the membrane walls, together with the two corner regions, define a flat tube.The membrane section is shaped in such a way that the membrane walls lie flat against each other, whereby the length of the membrane walls parallel to the central axis ensures that a fluid flowing through in the direction of the base section is reliably prevented.

[0010] In one embodiment, the membrane section, at least in the blocked state, has a substantially flat and planar extension parallel to a gap plane, with the central axis lying in the gap plane. The flat basic state of the membrane section allows a particularly large contact surface between the membrane walls, which enables reliable sealing, in particular in the case where the pressure at the distal end facing away from the base section is greater than in the base section. In this case, the membrane walls are pressed against one another by the external pressure, resulting in a greater tightness of the membrane section, which reinforces the blocked state.

[0011] In one embodiment, the base section is cup-shaped and open at the end facing away from the transition area. The cup-shaped design of the base section allows splash water to collect in the upper area of the closure, but even with slight overpressure in the tank, it can flow out of the tank interior via the membrane section. At the same time, fluid standing in the base section serves to further seal against the ingress of gas, which may contain harmful aerosols.

[0012] In one embodiment, an overpressure in the base body compared to the pressure at a distal end of the membrane section puts the membrane section into the permeable state, such that a fluid can flow from the base section towards the distal end, wherein the overpressure is preferably in the range from 50 Pa to 600 Pa, particularly preferably from 90 Pa to 400 Pa. The particularly easily deformable elastic material of the membrane section is designed so that even a slight overpressure in the tank compared to the environment ensures that the membrane section reaches the permeable state. This allows excess air (when filling the tank) or liquid (when overfilling the tank) to reliably escape through the closure into the riser pipe. The initially particularly broad range of 50-600 Pa preferably covers all operating conditions present in mobile homes and caravans.The range of 90-400 Pa has proven particularly suitable for use in motorhomes, which are mainly used in Europe and at altitudes of up to 2000 m above sea level.

[0013] In one embodiment, the base section has a collar which has a greater extension orthogonal to the central axis than the wall section. The collar is preferably a concealed area at the upper edge of the base section. The collar is designed to be placed on the blunt end of a riser pipe and brought into contact there. In a particularly preferred embodiment, the collar is intended to be slipped over the blunt end of a riser pipe such that the base section on the inner side and the collar on the outer side of the end of the riser pipe enclose this and thus form a particularly strong and sealed connection with the riser pipe. The collar is particularly preferably formed together with the base section as part of a one-piece closure.

[0014] In one embodiment, the membrane section has a maximum membrane length measured parallel to the central axis, wherein the membrane section has a maximum membrane width measured orthogonal to the central axis, wherein the membrane length is in a ratio of preferably 0.7 to 2, particularly preferably 0.9 to 1.5 to the membrane width. It has been shown that the best compromise between sufficient sealing and simultaneous material savings can be achieved when the length of the membrane walls along the central axis is approximately as large as their width orthogonal to the central axis. The longer the membrane length relative to the membrane width, the longer the path over which sealing can be achieved in the membrane section. At the same time, assembly is easier and material savings are improved when the membrane length is approximately as large as or slightly smaller than the membrane width.It is understood that the membrane width can also be designed to be significantly smaller than the internal width available in the riser pipe, in particular in order to provide a smaller passage area in the membrane section and to establish a higher seal and, if necessary, a higher pressure difference until fluid escapes from the tank.

[0015] In one embodiment, the membrane length is in a ratio of 0.2 to 0.7 and preferably 0.3 to 0.6 to a total length of the closure measured parallel to the central axis. The membrane length in relation to the total length of the closure along the central axis is thus an expression of how high the proportion of the membrane is in comparison to the base section, in particular to the wall section of the base section. In particular, in the case that a smooth riser pipe only requires a short length of the wall section parallel to the central axis, the membrane section can take up a higher proportion of the length of the closure. The particularly preferred range of 0.3 to 0.6 has proven to be the best compromise between a sufficient sealing length in the wall section and a sufficient membrane length to achieve a secure blocking state in the membrane section.

[0016] In one embodiment, the base section has a maximum diameter measured orthogonal to the central axis, the membrane width being in a ratio of 0.5 to 0.95, preferably 0.7 to 0.8, to this maximum diameter. Alternatively or additionally, the diameter is in a ratio of 0.2 to 0.7, preferably 0.3 to 0.5, to a total length of the closure measured parallel to the central axis. The ratio of the membrane width to the diameter of the base section particularly illustrates the width of the membrane compared to the generally available internal width of a riser pipe. A particularly wide membrane section can in particular achieve a large passage opening in the passage state, thereby simplifying the overflow of excess air or fluid from the tank.Alternatively, it may be preferred that only a small passage opening is provided by a particularly narrow membrane, thereby increasing the sealing effect of the closure. In the case of a rectangular or square cross-section of the base section, the maximum diameter is defined as the largest diagonal that can be drawn through the base section perpendicular to the central axis. In the simpler case of an essentially circular cross-sectional geometry of the base section, the diameter is correspondingly the circular diameter of the outermost outer surface of the base section. In the event that the base section has a collar, the maximum diameter of the base section is preferably in the region of the collar. In the event that the base section does not have a collar, the maximum diameter is to be measured in the region of the wall section.The ratio of the largest diameter of the cap in the base section to the total length of the cap reflects the particularly proven design and scaling of caps for use in riser pipes of various sizes. The particularly preferred range of 0.7-0.8 is a special design for use in standardized riser pipes in motorhome tanks.

[0017] In one embodiment, the first and second membrane walls extend, at least in the blocked state, substantially parallel to a gap plane, wherein at least one, preferably both, of the membrane walls has a wall thickness measured orthogonally to the gap plane, which amounts to 0.75% to 5%, preferably 1% to 2% of a maximum extension length of the respective membrane wall orthogonal to the pipe axis. The particularly small wall thickness of the membrane walls allows for easy deformation of the membrane walls. Thus, the membrane section reacts particularly sensitively and directly to pressure changes and can enable improved sealing or easy venting of the tank.

[0018] According to the invention, a tank system is further provided, comprising a tank and a riser pipe which extends at least partially inside the tank, wherein a closure with the features described above is fixed in or on a first end region of the riser pipe, such that the riser pipe is sealed by the closure, wherein the riser pipe opens into the environment at a second end region. In addition to the conventional tank known from the prior art, the tank system comprises a basically known riser pipe which, however, does not have a pressure relief valve or an unsealed opening at its distal end region located inside the tank, but is equipped with a closure according to the above description. The closure is preferably arranged only at a distance of 2 mm to 3 cm below the inner wall of the tank, which enables a particularly great length of the riser pipe.Furthermore, this minimizes the sloshing of liquid into the cap, especially while the motorhome or caravan is moving. In the embodiment in which only one cap allows flow in one direction, particularly the direction leading from the tank into the riser pipe and into the environment, the cap is designed to function as a one-way valve.

[0019] In one embodiment of the tank system, a T-piece is provided at the first end region, wherein a first closure is arranged in a first outlet of the T-piece such that the membrane section of the first closure extends in the direction of the riser pipe, and wherein a second closure is arranged in a second outlet of the T-piece such that the membrane section of the second closure points away from the riser pipe. The T-piece can be designed as a separate pipe section that can be placed on the distal end of a riser pipe. Alternatively, the T-piece is preferably designed as an integral and one-piece component of a riser pipe. A closure can thus be arranged in each of the two open end sections of the T-piece, which are arranged inside the tank, wherein a first closure allows flow into the tank and a second closure allows flow out of the tank.Inflow into the tank is preferred to prevent the development of a vacuum and thus a pressure drop in the corresponding piping systems of the motorhome or caravan in the event of a large amount of fluid being drawn from the tank, by allowing sufficient amounts of air to flow into the tank. The crucial factor here is that for this inflow to occur, a certain, previously described minimum pressure difference must be present at the cap. Otherwise, the cap is in a locked state, which generally prevents the flow of fluid and thus also of foreign matter into the tank.

[0020] Further advantages and features of the present invention will become apparent from the following description of selected embodiments with reference to the accompanying figures. It is understood that individual features shown only in certain embodiments can and should also be used in other embodiments, unless this is prohibited due to technical circumstances or explicit mention.

[0021] They show: Fig. 1 - a view of an embodiment of a closure; Fig. 2 and Fig. 3 - two sectional views of the Fig. 1 shown embodiment; Fig. 4 and Fig. 5 - two embodiments of riser pipes with closures arranged therein; Fig. 6 - a schematic view of an embodiment of a closure; and Fig. 7 - a view of a tank system.

[0022] The Fig. The closure 4 shown in Figure 1 is shown in a side view in which the gap plane S is perpendicular to the viewing plane. At the same time, the central axis M lies in the gap plane S in this view. The closure 4 has a base section 5, which in this embodiment has a wall section 52, a transition section 54 and a collar 56. In the area between the collar 56 and the wall section 52, a transition area that tapers essentially in the shape of a truncated cone is provided. Using this transition area, the closure 4 can be placed onto the blunt end of a riser pipe 10, with the collar 56 then being slipped over this open end of the riser pipe 10. As an alternative to being slipped over, the closure 4 can also be supported in this area on the open end of the riser pipe 10.The wall section 54 is intended to rest against the inside of the riser pipe 10 and, in this embodiment, has a cylindrical outer geometry. The membrane section 6 extends downwards substantially parallel to the central axis M and, in this embodiment, also parallel to the gap plane S. A transition section 54 having a substantially V-shaped cross-section is provided between the membrane section 6 and the wall section 52 of the base section 5. The membrane section 6 has a membrane length 65 between its connection to the transition section 54 and its lower, distal end 67, which, in this embodiment, is slightly less than half the total extension of the closure 4 parallel to the central axis M.

[0023] Fig. 2 shows the Fig. 1 in the area of the wall section 52 of the base body 5. The position of the membrane section 6 can be seen here, which extends centrally and on the underside of the transition section 54 essentially parallel to the gap plane S. The central axis M is advantageously located in the circle center of the cylindrical outer geometry of the wall section 52. In Fig. 2 schematically shows the blocking state Z of the membrane section 6, in which the membrane walls 61, 62 lie directly against one another.

[0024] Fig. 3 shows the detailed view, which in Fig. 2. It can be seen that the membrane section 6 preferably has a first membrane wall 61 and a second membrane wall 62, which extend essentially parallel to one another and parallel to the gap plane S. Fig. 3 shows the permeability state A, in which a gap 68 is formed between the membrane walls 61, 62, through which gap a fluid can flow. At their respective end regions, the first membrane wall 61 and the second membrane wall 62 are each connected to one another by a corner region 63. The membrane section 6 thus forms a flat, tubular section which is closed in its basic state, such that the membrane walls 61, 62 abut one another, thus creating the blocking state Z of the membrane section 6. Only in the permeability state A, which can be achieved by means of an overpressure in the base body 5, are the membrane walls 61, 62 spaced apart from one another in such a way that a gap 68 is formed, through which fluid can pass. The wall thickness w of the membrane walls, measured orthogonally to the gap plane S, is preferably approx.1% to 2% of a maximum extension length of the respective membrane wall 61, 62 orthogonal to the tube axis R, i.e. the membrane width 66.

[0025] Fig. 4 shows a first embodiment of a riser pipe 10 with a first end region 11 arranged at the top and a second end region 12 arranged at the bottom. Adjacent to the second end region 12, the riser pipe is attached to the lower wall of a tank 2 (see Fig. 7) and open to the environment. At its first end region 11, the riser pipe 10 is closed by a closure 4 according to one of the embodiments of the Fig. 1-3 closed. In this embodiment, the closure 4 is inserted into the riser tube 10. The tube axis R of the riser tube 10 runs essentially collinear with the central axis M of the closure 4.

[0026] Fig. 5 shows a further embodiment of a riser pipe 10, in which, in contrast to Fig. 4, a T-piece 14 is placed on the first end region 11 of the riser pipe 10. Two closures 4 are inserted into this T-piece, which close the T-piece 14 and thus the first end region 11 of the riser pipe 10. One of the closures 4 is arranged such that its membrane section 6 extends into the T-piece 14, and thus allows a flow from the interior of the tank into the riser pipe 10. The second closure 4 is inserted in the T-piece 14 such that its membrane section 6 extends away from the T-piece 14. This closure 4 thus allows an inflow from the riser pipe 10 into the interior of the tank.

[0027] The schematic view of Fig. 6 shows the geometry of a preferred embodiment of a closure 4, wherein the maximum outer diameter D is set in relation to the membrane width 66. In this embodiment, the base section 5 preferably does not have a collar 56, and the wall section 52 is thus the area in which the largest outer diameter D of the base section 5 is present.

[0028] Fig. Finally, Figure 7 shows an embodiment of a tank 2 of a tank system according to the present invention. Arranged in this tank 2 is a riser pipe 10, which is open to the environment at its lower, second end region 12 and closed by a closure 4 at its upper, first end region 11 located within the tank 2. List of reference symbols: 2 tanks 4 Closure 5 Basic section 6 Membrane section 10 riser pipe 11 first end area 12 second end area 14 T-piece 52 wall section 54 Transition area 56 collar 61 first membrane wall 62 second membrane wall 63 Corner area 65 membrane length 66 membrane width 67 distal end 68 gap A conduction state D Diameter M central axis R tube axis S cleavage plane w wall thickness Z Lock state

Claims

[1] Closure (4), in particular for use in a tank (2), comprising a base section (5) and a membrane section (6), wherein the base section (5) has a jacket-shaped wall section (52) and a transition region (54) adjacent thereto, wherein the membrane section (6) borders on the transition region (54) and protrudes from the transition region (54) along a central axis (M), wherein the membrane section (6) is designed to be brought into a blocking state (Z) or into a passing state (A), wherein the membrane section (6) is substantially fluid-impermeable in the blocking state (Z), and wherein the membrane section (6) is fluid-permeable along the central axis (M) in the permeable state (A). [2] Closure (4) according to claim 1, wherein the wall portion (52) is substantially axially symmetrical and / or rotationally symmetrical about the central axis (M) and preferably has a circular cross-section. [3] Closure (4) according to one of the preceding claims, wherein at least the membrane section (6) is formed from an elastically deformable material having a Shore hardness of 20 to 90 Shore A, preferably of 50 to 70 Shore A. [4] Closure (4) according to one of the preceding claims, wherein the membrane section (6) has a first membrane wall (61) and a second membrane wall (62) opposite the first membrane wall (61), wherein the first and second membrane walls (61, 62) in the blocking state (Z) lie against each other substantially over their entire surface, and wherein in the passage state (A) between the first membrane wall (61) and the second membrane wall (62) has a gap (68) formed therein which is fluid-permeable along or parallel to the central axis (M). [5] Closure (4) according to one of the preceding claims, wherein the membrane section (6) has, at least in the blocking state (Z), a substantially flat and planar extension parallel to a gap plane (S), wherein the central axis (M) lies in the gap plane (S). [6] Closure (4) according to one of the preceding claims, wherein the base portion (5) is cup-shaped and is open at its end facing away from the transition region (54). [7] Closure (4) according to one of the preceding claims, wherein an overpressure (P) in the base body (5) compared to the pressure at a distal end (67) of the membrane section (6) puts the membrane section (6) into the permeable state (A) such that a fluid can flow from the base section (5) towards the distal end (67), wherein the overpressure is preferably in the range from 50 Pa to 600 Pa, particularly preferably from 90 Pa to 400 Pa. [8] Closure according to one of the preceding claims, wherein the base portion (5) has a collar (56) which has a greater extension orthogonal to the central axis (M) than the wall portion (52). [9] Closure (4) according to one of the preceding claims, wherein the membrane section (6) has a maximum membrane length (65) measured parallel to the central axis (M), wherein the membrane section (6) has a maximum membrane width (66) measured orthogonally to the central axis (M), wherein the membrane length (65) is in a ratio of preferably 0.7 to 2, particularly preferably 0.9 to 1.5 to the membrane width (66). [10] Tank system, in particular tank system of a motorhome or caravan, comprising a tank (2) and a riser pipe (10) which extends at least partially inside the tank (2), wherein in or at a first end region (11) of the riser pipe (10) a closure (4) according to one of claims 1-9 is fixed, such that the riser pipe (10) is sealed by the closure (4), wherein the riser pipe (10) opens into the environment at a second end region (12).

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