Abstract
A fuel tank for receiving a fluid in a motor vehicle. The fuel tank includes an outer wall forming an internal space for receiving the fluid. At least one volume element is arranged in the internal space for receiving air, and an opening that is a gas-guiding line between the volume element and the environment of the tank is for changing the volume of the volume element. The at least one volume element is formed at least partially as bellows.
Claims
1. A fuel tank for holding a fluid in a motor vehicle, the fuel tank comprising: an outer wall, which forms an interior space for holding the fluid, at least one volume element arranged in the interior space for holding gas, in particular air, and an opening, in particular a line carrying the gas, between the at least one volume element and surroundings of the tank for changing a volume of the volume element, wherein the at least one volume element includes bellows.
2. The tank according to claim 1, wherein the bellows have at least two layers, specifically an inner layer and an outer layer, and wherein the inner layer is manufactured of a different material than the outer layer.
3. The tank according to claim 1, wherein the bellows have at least three layers including an inner layer having an inner layer thickness, a middle layer having a middle layer thickness, and an outer layer having an outer layer thickness, and wherein the middle layer is manufactured of a different material than the inner layer and the outer layer.
4. The tank according to claim 3, wherein the middle layer thickness is 5 to 800 m.
5. The tank according to claim 3, wherein the middle layer thickness is thinner than the outer layer thickness and/or thinner than the inner layer thickness.
6. The tank according to claim 3, wherein the middle layer thickness is 1% to 25% of a total thickness of the bellows.
7. The tank according to claim 1, wherein the volume element further includes: at least one support ring disposed on an inner side of an outward pointing folding point of the bellows, and/or at least one ring-shaped reinforcement layer disposed on an outer side of the outward pointing folding point of the bellows, and/or at least one ring-shaped upset disposed at the outward pointing folding point of the bellows.
8. The tank according to claim 1, wherein the bellows are conical or frustoconical.
9. The tank according to claim 1, wherein the bellows are folded in a spiral-shaped manner.
10. The tank according to claim 1, wherein the at least one volume element further includes a first element wall and a second element wall, and the first and second element walls are joined to the bellows or are at least partially defined by the bellows.
11. The tank according to claim 10, wherein at least one of the first element wall or the second element wall is rigid, and the bellows are: blow-molded to the at least one of the first element wall or the second element wall, or joined in a material-bonded or formfitting manner to the at least one of the first element wall or the second element wall.
12. The tank according to claim 10, wherein at least one of the first element wall or the second element wall is rigid and has multiple layers of various plastics.
13. The tank according to claim 10, wherein at least one of the first element wall or the second element wall is formed by the bellows and has at least one ring-shaped, structure-reinforcement element.
14. The tank according to claim 10, wherein at least one spacing element is arranged between the first element wall and the outer wall.
15. The tank according to claim 1, further comprising at least one guide arrangement for guiding the bellows when unfolding and folding parallel to a fold axis (Z) thereof and for limiting a movement of the bellows perpendicular to the fold axis (Z).
16. The tank according to claim 1, further comprising a protective sleeve surrounding the bellows.
17. The tank according to claim 1, further comprising at least one spring, wherein the elastic spring is arranged to place a load on the bellows in a direction of a folded state and/or an unfolded state.
18. The tank according to claim 1, further comprising at least one sensor for determining the volume of the volume element.
19. The tank according to claim 1, further comprising at least one actuator for actively changing the volume of the volume element.
20. The tank according to claim 1, further comprising at least one detachable holding arrangement, which holds together at least two adjoining folds of the bellows in a folded state thereof.
21. The tank according to claim 1, wherein the at least one volume element includes at least one active volume element and at least one reserve volume element in the interior space, and wherein a volume of the at least one active volume element is configured to be changed via a connection to the line carrying the gas, while the at least one reserve volume element remains in a folded state thereof until used.
22. The tank according to claim 21, wherein the at least one active volume element and the at least one reserve volume element are each simultaneously connected via a separate connector (16) to the line carrying the gas.
23. The tank according to claim 21, wherein volumes of the at least one active volume element and the at least one reserve volume element are connected directly to each other.
Description
[0099] Additional details, features and advantages of the invention are found in the description and drawings below. Depicted are:
[0100] FIGS. 1 to 9 various embodiments of the tank according to the invention having a volume element designed as bellows,
[0101] FIGS. 10 to 13 various embodiments of the tank according to the invention having a volume element, wherein the bellows have active and passive regions,
[0102] FIGS. 14 to 17 various embodiments of the tank according to the invention having two volume elements, each designed as bellows,
[0103] FIG. 18 a volume element designed as bellows with bistable folds, and
[0104] FIG. 19 a schematic illustration regarding FIG. 18,
[0105] FIG. 20 a volume element designed as bellows having waves on the intermediate surfaces, and
[0106] FIG. 21 a volume element having additional advantageous designs.
[0107] The drawings schematically show various embodiments of a tank 1. The tank 1 is used in a motor vehicle in particular.
[0108] The tank 1 comprises an outer wall 2, which forms an interior space 3 for holding fuel. There is at least one volume element 4 in the interior space 3. A lid 5 for opening an opening may be designed on the outer wall 2.
[0109] A gas-carrying line 6 leads to the tank 1. Said line is connected in a gas-carrying manner to the at least one volume element 4.
[0110] Various embodiments of the tank 1 and the volume element 4 are described in detail below. These various embodiments can be preferably combined with each other.
[0111] FIG. 1 shows that the volume element 4 comprises two opposing element walls, specifically a first element wall 11 positioned at the top and an opposing element wall 12. The two element walls 11, 12 of the volume element 4 are connected to each other via bellows 10. When the volume element breathes, the bellows 10 move along the drawn-in fold axis Z.
[0112] A connector 16 in the form of a nipple is designed at the first element wall 11. This connector 16 protrudes through the outer wall 2 outwards and is connected to the gas-filling line 6.
[0113] Furthermore, FIG. 1 shows the possibility of arranging at least one spacing element 17 between the first element wall 11 and the outer wall 2 of the tank 1. The outer wall 2 of the tank 1 can be produced by inflating a plastic mold. The volume element 4 can thereby be arranged in the tank 1 being formed prior to inflation. After inflating the outer wall 2, it cools down. So as not to damage the volume element 4 due to heating during inflation or subsequent cooling, said volume element is preferably set at a distance by the at least one spacing element 17.
[0114] Furthermore, FIG. 1 shows the schematic arrangement of a guide arrangement 56 as an optional design. The guide arrangement 56 comprises multiple guide elements 57. The guide elements 57 are firmly connected to the outer side of the bellows at various positions. Furthermore, the guide arrangement 56 comprises a guide 58. The guide 58 is here designed as a telescoping rod that extends along fold axis Z. The guide elements are guided in a sliding manner along the guide 58. The schematic illustration in FIG. 1 shows only one guide 58 solely for illustrative purposes. However, several of these guides 58 can in fact be used. In particular, more than the two depicted guide elements 57 are also used.
[0115] The guide arrangement 56 guides and stabilizes the bellows 10 in the folding and unfolding process, and thus in its movement parallel to the fold axis Z. A movement perpendicular to the fold axis Z is prevented or limited by the guide arrangement 56.
[0116] In a detailed illustration, FIG. 2 depicts the multi-layer structure of the wall of the bellows 10 having inner layer 13, middle layer 14 and outer layer 15. The bellows 10 has a total thickness 10a made up of the sum of the thicknesses of all layers. The outer layer 15 has an outer layer thickness 15a, the inner layer 13 has an inner layer thickness 13a and the middle layer 14 has a middle layer thickness 14a. The dimensions and materials for the layers were already advantageously defined in the general portion of the description. The outer layer thickness 15a is thinner than the inner layer thickness 13a.
[0117] Furthermore, FIG. 2 shows that the bellows alternatingly have a plurality of inward pointing folding points 18 and outward pointing folding points 19. There are intermediate surfaces 20 in each case between the folding points. FIG. 2 depicts the arrangement of support rings 21 on the interior side of the folding points 18, 19. It is possible to arrange support rings 21 at all or some folds. Furthermore, it is possible to arrange the support rings 21 both inside as well as outside or between the layers 13, 14, 15.
[0118] It is provided in particular that a support ring 21 is inserted at at least one outward pointing folding point 19 (external fold) on the inner side of the wall of the bellows 10. The support ring 21 is preferably not joined to the bellows 10, but only inserted.
[0119] In addition or as an alternative to the described rigid support ring 21, at least one fold, particularly an external fold, can be stabilized by a reinforcement layer 15b. As FIG. 2 shows, the reinforcement layer 15b is preferably located on the outer side of the bellows 10 and extends in a ring-shaped, fully circumferential manner at at least one outward pointing folding point 19 and thus forms a support ring.
[0120] In addition or as an alternative to the described rigid support ring 21 or the support ring formed from the reinforcement layer 15b, at least one outer fold can have an upset 71, which forms a support ring. This variant is described in FIG. 21. In regard to the upset 71, the blow-molding tool can produce a material indentation on the inner side of the folding point, said indentation supporting the reinforcing effect of the upset 71.
[0121] Furthermore, FIG. 2 depicts perpendicular to the Z axis a large diameter 7 of the volume element 4 at the first element wall 11 and a small diameter 8 of the volume element 4 at the second element wall 12. This design of the diameters 7, 8 results in a frustoconically shaped volume element 4. The side with the larger diameter 7 is preferably arranged at the top and contacts the outer wall 2.
[0122] FIG. 3 depicts a support element 30 in the form of a housing as a guide arrangement 56. This support element 30 is arranged directly on the outer side of the unfolded bellows 10 and limits any movement of the bellows 10, for example caused by the fluid moving in the interior space 3.
[0123] In addition, the support element 30, designed as a guide arrangement 56, guides the bellows during folding and unfolding, and thereby limits any movement perpendicular to fold axis Z.
[0124] FIG. 4 depicts another possible design of the guide arrangement 56. In this regard, the left side of FIG. 4 shows the folded bellows 10. On the right side, FIG. 4 depicts the folded bellows. According to FIG. 4, the guide arrangement 56 is formed by the outer wall 2 extending into the interior space of the bellows 10. This region of the outer wall 2 can alternatively also be formed by a lid 5, which represents a part of the outer wall 2.
[0125] By the outer wall 2 extending into the interior of the bellows 10 according to FIG. 4, this region of the outer wall 2 can at least partially support and/or guide the bellows. Thus, this inwardly curved region of the outer wall 2 also limits a movement of the bellows 10 perpendicular to the fold axis Z.
[0126] FIG. 5 depicts a possible design of the bellows 10 having spiral-shaped folding. When unfolding and folding the bellows 10 along the Z axis, the second element wall 12 rotates relative to the first element wall 11 about the Z axis.
[0127] Here, the support ring 21 is designed in a spiral shape and can simultaneously also be used as an elastic element 36. The elastic element 36 is explained in more detail using FIG. 6.
[0128] Furthermore, FIG. 5 shows the use of a distance sensor 31. Here, the distance sensor 31 is arranged on the inner side of the first element wall 11 and it measures the distance to the second element wall 12. To do so, there is preferably on the second element wall 12 a corresponding counter-piece 32, designed as a reflector for example. The distance sensor 31 can operate optically or electromagnetically or acoustically, for example. By measuring the distance between the two element walls 11, 12, a corresponding control unit can calculate the current volume of the volume element 4. The use of the distance sensor 21 is thereby independent of any spiral-shaped folding of the bellows 10.
[0129] Given the spiral-shaped folding, the counter-piece 32 rotates relative to the distance sensor 31. As a result, the distance sensor 31 can also record an angle of rotation to the counter-piece 32 and thereby deduce the distance.
[0130] Besides using a distance sensor 31 inside the volume element 4, FIG. 6 shows other possible sensors that can also be used to obtain information about the volume of the volume element 4.
[0131] Thus, FIG. 6 shows for example a distance sensor 31 on the bottom of the outer wall 2, which measures the distance to the second element wall 12, if applicable also using a counter-piece 32.
[0132] Additionally or alternatively, a pressure sensor 33 can be used, which measures for example the pressure in the interior space 3 outside of the volume element 4 or (not depicted) the pressure in the volume element 4.
[0133] Aside from the sensors, FIG. 6 depicts a possible arrangement of an elastic element 36, here in the form of a spring. In the depicted example, the elastic element 36 is arranged inside the volume element 4. The elastic element 36 is braced inside the volume element 4 against the second element wall 12 and is supported on the opposite side for example inside the connector 16. In particular, this elastic element 36 can also be introduced through the connector 16 into the interior of the volume element 4. Alternatively, the elastic element can be attached to the upper wall as is shown with 36 in FIG. 6.
[0134] As an alternative to this, it is also possible to arrange an elastic element 36 on the bottom side of the second element wall 12 and brace it against the outer wall 2.
[0135] Furthermore, FIG. 6 depicts the use of a lever 34, which is rotatably hinged in the interior space 3 and is connected to the second element wall 12. The movement of this lever can be recorded for example using an angle sensor 35, by means of which information can be obtained regarding the current volume of the volume element 4.
[0136] Furthermore, the tank 1 may comprise at least one actuator 37 with which it is possible to actively influence the volume of the volume element 4. This can be done particularly based on the volume determined by the sensors 31, 33, 35.
[0137] A possible actuator 37 is a pump, with which gas can be pumped or suctioned into the volume element 4 via the connector 16. In addition, it is possible to arrange an actuator 37 in the form of an electric drive on the lever 34. The lever 34 can thereby be moved with the actuator 37, by means of which the second element wall 12 is in turn moved with respect to the first element wall 11.
[0138] FIG. 7 depicts in a purely schematic manner an embodiment in which the bellows 10 is designed more stiffly on one side than on an opposite side. This design of the bellows 10 can be combined with all other designs presented here. FIG. 7 highlights how the various rigidities of the folds of the bellows 10 make it possible for the bellows to unfold and fold asymmetrically. In this way, the bellows 10 can be adapted to specific geometries of the interior space 3.
[0139] FIG. 8 highlights in a purely schematic manner that the bellows can be directly open in an upward direction and can be connected to the surroundings via a corresponding opening in the outer wall 2. In this design, no gas-carrying line 6 is necessary; instead, the interior of the bellows 10 opens directly to the surroundings.
[0140] FIG. 9 depicts a simple way to replace the volume element 4. According to FIG. 9, a lid 5 is arranged in the outer wall 2. The volume element 4 is arranged on the inner side of this lid 5. The lid 5 closes an opening, which is large enough to remove the lid along with the volume element 4 from the interior space 3.
[0141] FIG. 10 shows a variant in which multiple adjoining folds of the bellows 10 are held together in a folded state by means of a holding arrangement 40. In this example, the holding arrangement 40 is designed as a clip, which is applied on the bellows 10 from the outside. The holding arrangement 40 thus holds certain folds of the bellows 10 together, which form a reserve region of the bellows 10. By removing this holding arrangement 40 and if applicable by placing the holding arrangement 40 at other folds of the bellows 10, the reserve region can be activated.
[0142] FIG. 11 shows that the holding arrangement 40, as was explained by means of FIG. 10, can also be arranged inside the bellows 10. It is thereby particularly provided that the lid 5 is arranged in the outer wall 2 of the tank 1 in such a manner that by opening the lid, the interior of the bellows 10 is directly accessible. The holding arrangement 40 can thereby be detached by a person.
[0143] The lid 5 shown in FIG. 11, which allows direct access inside the bellows 10, can also be used independently of the depicted holding arrangement 40 to allow a repair of the bellows 10 from the inside, for example.
[0144] FIG. 12 depicts a design of the holding arrangement 40 having two opposing elements, which interlock or otherwise hold together, for example magnetically. In the illustration according to FIG. 12, the lower half of the bellows 10 is passive and serves as a reserve. After corresponding wear or for example a leak, the holding arrangement 40 can be placed in such a manner that the upper half of the bellows 10 becomes passive and the lower half of the bellows 10 is used for breathing.
[0145] FIG. 13 depicts a similar variant as in FIG. 12. However, here the holding arrangement 40 is located inside the bellows 10 in the form of a quick connector. The advantage of the device is that a leak in the upper part would not influence emissions because it is sealed off.
[0146] Furthermore, FIG. 13 shows that the bellows 10 is subdivided by a separating wall 43. The separating wall 43 has an opening so that the two regions of the bellows are connected to each other. Located at this opening as well as at the first element wall 11 or at the connector 16 is the holding arrangement 40, which allows one to connect this opening of the separating wall 43 directly to the connector 16. This occurs when the holding arrangement 40 of the lower region of the bellows is detached and the upper region of the bellows 10 is set to be passive. The holding arrangement 40 in the first volume element 4 is simultaneously designed as a connecting arrangement 41, which allows a simple and detachable connection of the opening of the separating wall 43 to the gas-carrying line 6. To release the lower holding arrangement 40 (e.g., in the workshop, during a repair or a service), one can connect the connecting arrangements 41 at the top, and pressurize the volume element 4 until the holding arrangement 40 tears.
[0147] FIG. 14 shows a variant in which two volume elements 4 are located in the interior space 3. While the one volume element 4 breathes through its connection to the gaseous line 6, the reserve volume element 4 remains in the folded state, held by the holding arrangement 40, at any location in the interior space 3. In particular, the connector 16 of the reserve volume element 4 is thereby closed by a closure 42 (cap) so that no fuel can enter inside the reserve volume element 4. When replacing the volume elements 4, the first volume element 4 is pulled off. The closure 42 is removed from the reserve volume element 4 so that the connector 16 of the reserve volume element 4 can be connected to the corresponding opening in the outer wall 2. To this end, detachable connection arrangements 41 are preferably provided on the outer wall 2 and at the connectors 16.
[0148] FIG. 15 depicts a variant, in which there are also two volume elements 4 in the interior space 3. The reserve volume element 4 is thereby again held in the folded state by means of a holding arrangement 40. Both volume elements 4 are always connected by their own connectors 16 to the common gas-carrying line 6. By the corresponding detachment and placement of the holding arrangements 40 in the first volume element 4 or in the reserve volume element 4, one can determine which volume element remains in the folded state and which volume element 4 breathes.
[0149] Like FIG. 15, FIG. 16 shows two volume elements 4, each as bellows 10, inside tank 1. Both volume elements 4 are connected via their own gas-carrying lines 6 to the surroundings. However, in the variant according to FIG. 16, no holding arrangements 40 are required. According to FIG. 16, both lines 6 of both volume elements 4 are connected to each other via a three-way valve 61. By the corresponding switching of the three-way valve 61, either one or the other volume element 4 can be utilized.
[0150] Preferably, pressure relief valves 60 are then used at each volume element 4 to ensure that the closed volume element 4 always remains in a displaced state, despite diffusion through its wall.
[0151] FIG. 17 also shows an arrangement having two volume elements 4 in the interior space 3. This arrangement corresponds to the illustration in FIG. 9 with the difference that it hereby does not involve a single bellows 10, which is subdivided by a separating wall 43, but two separate bellows 10, which are connected to each other. In contrast to FIG. 13, the first volume element 4 according to FIG. 17 has a holding arrangement 40, which is constructed separately from the connection arrangement 41.
[0152] FIG. 18 shows the possibility of designing the folds of the bellows 10 in a bistable manner. In this regard, FIG. 18 shows a bistable fold 55, wherein in particular multiple or all folds can be designed as bistable folds 55.
[0153] Relating to FIG. 18, FIG. 19 shows the advantageous trend of the volume in the bellows 10 as a function of the pressure in the volume element 4 as a dashed line using bistable folds 55 for all folds compared to conventional stable folds having a continuous line.
[0154] FIG. 20 depicts in a purely schematic illustration for all embodiments shown here that to assist a uniform movement of the bellows 10 along the fold axis Z and to simplify breathing and to simultaneously stabilize the folds, it may be optionally provided that the intermediate surfaces 20 located between the folding points have waves 62 and are thus designed in a wave-shaped manner or having a wave structure.
[0155] The first element wall 11 and/or the second element wall 12 can be designed as rigid panels. Alternatively, one can integrate circumferential radial folds in the bottom, so that the bottom can move slightly upward inside the outer folds to further decrease the minimum volume. In this case, the element wall 12 is no longer a rigid panel. FIG. 20 depicts this design, which can be used with or without the wave 62.
[0156] FIG. 21 depicts additional possible embodiments of the volume element 4, which can be used individually or in combination with other features of the invention:
[0157] Relating to FIG. 2, support rings 21 or a reinforcement layer 15b were described to form a type of support ring. In addition or as an alternative to this, FIG. 21 depicts a fully circumferential upset 71 for illustrative purposes on a fold, which forms by means of its material thickening a support ring.
[0158] Furthermore, FIG. 21 depicts a rigid first element wall 11. The bellows 10 is blow-molded on to the first element wall 11. The same structure also results when the first element wall is adhesively joined or welded to the bellows.
[0159] Furthermore, FIG. 21 shows that the bottom of the bellows 10 or the second element wall 12 may comprise a ring-shaped structure-reinforcement element 70.
LIST OF REFERENCE SIGNS
[0160] 1 Tank [0161] 2 Outer wall [0162] 3 Interior space [0163] 4 Volume element [0164] 5 Lid [0165] 6 Gas-carrying line [0166] 7 Large diameter [0167] 8 Small diameter [0168] 10 Bellows [0169] 10a Total thickness [0170] 11 First element wall [0171] 12 Second element wall [0172] 13 Inner layer [0173] 13a Inner layer thickness [0174] 14 Middle layer [0175] 14a Middle layer thickness [0176] 15 Outer layer [0177] 15a Outer layer thickness [0178] 15b Reinforcement layer [0179] 16 Connector [0180] 17 Spacing element [0181] 18 Inward pointing folding point [0182] 19 Outward pointing folding point [0183] 20 Intermediate surfaces [0184] 21 Support rings [0185] 30 Support element as guide arrangement 56 [0186] 31 Distance sensor [0187] 32 Counter-piece [0188] 33 Pressure sensor [0189] 34 Lever [0190] 35 Angle sensor [0191] 36 Elastic element [0192] 37 Actuator [0193] 40 Holding arrangement [0194] 41 Connecting arrangement [0195] 42 Closure [0196] 43 Separating wall [0197] 50 Outgoing flow [0198] 51 Leak [0199] 55 Bistable fold [0200] 56 Guide arrangement [0201] 57 Guide element [0202] 58 Guide [0203] 59 Filter [0204] 60 Pressure relief valve [0205] 61 Three-way valve [0206] 62 Wave structure [0207] 70 Structure-reinforcing element [0208] 71 Upset
