MOTOR-VEHICLE LIQUID TANK HAVING AN INTEGRATED FLOAT VALVE

Abstract

A liquid tank, in particular for a motor vehicle, encompassing: a tank shell surrounding an internal tank volume; and at least one tank opening for filling the tank as intended with a liquid that is to be stored and/or for removing stored liquid as intended from the tank, the tank further including a float valve that, depending on its operating position, opens or closes for a flow of fluid a valve opening that passes through the tank shell and is different from the at least one tank opening, the tank further including a valve housing, which guides a float valve in its motion between its closed position in which it closes off the valve opening and its open position in which it enables a flow of fluid through the valve opening, is embodied in one piece with the tank shell.

Claims

1-11. (canceled)

12. A liquid tank, in particular for a motor vehicle, encompassing: a tank shell surrounding an internal tank volume; and at least one tank opening for filling the tank as intended with an associated liquid that is to be stored and/or for removing an associated stored liquid as intended from the tank, the tank further comprising a float valve that, depending on its operating position, opens or closes for a flow of fluid a valve opening that passes through the tank shell and is different from the at least one tank opening, wherein a valve housing, which guides a float valve in its motion between its closed position in which it closes off the valve opening and its open position in which it enables a flow of associated fluid through the valve opening, is embodied in one piece with the tank shell.

13. The liquid tank according to claim 12, wherein the tank shell comprises a one-piece lower tank shell comprising a tank bottom and a lower, during operation of the tank as intended, portion of tank side walls, and a one-piece upper tank shell comprising a tank lid and an upper, during tank operation as intended, portion of tank side walls, the valve housing being constituted in one piece with the upper tank shell.

14. The liquid tank according to claim 12, wherein the valve housing projects protrudingly from a tank shell portion into the internal tank volume.

15. The liquid tank according to claim 12, wherein the valve housing is configured tubularly and surrounds the float valve body regardless of the latter's operating position.

16. The liquid tank according to claim 15, wherein the tubular valve housing extending along a virtual tube axis comprises in its tube wall a guidance configuration that is in positive guidance engagement with a counterpart guidance configuration of the float valve body in such a way that the float valve body can move toward and away from the valve opening only along the guidance configuration.

17. The liquid tank according to claim 16, wherein the guidance configuration comprises a recess that is radial with respect to the virtual tube axis that notionally passes centrally through tubular valve housing; and the counterpart guidance configuration comprises a protrusion projecting into the recess.

18. The liquid tank according to claim 17, wherein the valve housing is embodied at its longitudinal end remote from the tank shell to be continuously encircling.

19. The liquid tank according to claim 16, wherein the valve housing is embodied at its longitudinal end remote from the tank shell to be continuously encircling.

20. The liquid tank according to claim 12, wherein the valve housing is open at its longitudinal end remote from the tank shell.

21. The liquid tank according to claim 12, wherein at least one of the float valve body encompasses a foamed material and the float valve body is embodied as a shell-like hollow body.

22. The liquid tank according to claim 21, wherein the float valve body is embodied as a bell-shaped, shell-like hollow body that is open toward the internal tank volume in a direction away from the valve opening.

23. A motor vehicle having a liquid tank according to claim 12.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The invention may take physical form in certain parts and arrangement of parts, a preferred embodiment of which will be described in detail and illustrated in the accompanying drawing which forms a part hereof and wherein:

[0030] FIG. 1 is a schematic longitudinal section through a motor-vehicle liquid tank according to the present invention.

DESCRIPTION OF PREFERRED EMBODIMENTS

[0031] Referring now to the drawings wherein the showings are for the purpose of illustrating preferred and alternative embodiments of the invention only and not for the purpose of limiting the same, in FIG. 1, an embodiment according to the present invention of a motor-vehicle operating-liquid tank is labeled in general with the number 10. In the example depicted, operating-liquid tank 10, arranged on a motor vehicle V, encompasses an upper tank shell 12 and a lower tank shell 14 that are joined to one another to yield tank 10 by means of radially externally proceeding connecting flanges 16 and 18, forming a joining surface 20 in a manner known per se. Connecting flanges 16 and 18 are preferably embodied in one piece respectively with upper tank shell 12 and with lower tank shell 14.

[0032] Tank 10 is depicted schematically in longitudinal section in FIG. 1, specifically in a reference state that corresponds to a state in which tank 10 is completely installed in a vehicle standing on a horizontal substrate. The direction of gravity, parallel to the drawing plane of FIG. 1, is labeled g in FIG. 1 for better comprehension.

[0033] Tank 10 encompasses a tank lid 22 that is located with a spacing, in direction of gravity g, oppositely from a tank bottom 24. Tank lid 22 and tank bottom 24 are connected to one another via tank side walls 26, 28, and 30. A further tank side wall is located in front of the drawing plane of FIG. 1 and is therefore not depicted.

[0034] Tank 10 surrounds a receiving space 32 that comprises an internal tank volume 31 and, in the reference state depicted in FIG. 1, is delimited at the top by tank lid 22, at the bottom by tank bottom 24, and laterally by tank side walls 26, 28, and 30 and by the further tank side wall (not depicted) that is located in front of the drawing plane.

[0035] Upper tank shell 12 and lower tank shell 14 are each constituted in one piece, for example by injection molding.

[0036] Tank 10 can be filled to a maximum fill height F, through a filler opening 34 that is preferably embodied in tank lid 22, with an operating liquid B. Operating liquid B can flow for that purpose in filling direction I, through filler opening 34, into receiving space 32.

[0037] Operating liquid B stored in receiving space 32 can likewise be withdrawn through a withdrawal opening 36 that is preferably embodied in tank bottom 24 which is located geodetically low. Operating liquid B then flows in withdrawal direction A out of tank 10 through withdrawal opening 36. A withdrawal module (not depicted in FIG. 1), which contains functional elements such as a delivery pump, a fill level sensor, a heating system, and the like, can be arranged for that purpose in withdrawal opening 36. The withdrawal module can then comprise a tapping opening to which a liquid conduit that leads to an injection apparatus can be connected, in order to inject liquid withdrawn from tank 10 (in this case e.g. aqueous urea solution or fuel) into an exhaust gas flow for selective catalytic reduction or into a combustion chamber of a combustion engine of motor vehicle V that carries tank 10.

[0038] Tank 10 furthermore comprises a float valve 38 that, depending on the fill level of operating liquid B in receiving space 32, opens up a valve opening 40 to allow gas to flow through out of gas space 42 above operating liquid B, or closes off valve opening 40.

[0039] Float valve 38 is thus part of an automatic shutoff system of an automatic tank filling system of tank 10. Specifically, when valve opening 40 is closed in terms of a flow of gas through it out of gas space 42, the pressure in internal tank volume 31 rapidly rises as filling continues, and can thereby trigger an automatic shutoff system in a nozzle. Overfilling of tank 10 can thereby be avoided.

[0040] Float valve 38 encompasses a tubular (in the example depicted, circularly cylindrically tubular) valve housing 44 that advantageously is embodied in one piece with upper tank shell 12. Valve 44 protrudes along a virtual tube axis R from tank lid 22 exclusively to one side, namely into internal tank volume 31.

[0041] The space enclosed by valve housing 42 toward virtual tube axis R does not change, in terms of either size or shape, along the tube axis in a direction away from tank lid 22, except for three guidance configurations 38 (only two of which are shown because of the location of the section plane in FIG. 1) that penetrate through tube wall 46 radially with respect to tube axis R.

[0042] A float valve body 50 is introduced into valve housing 44 from the open longitudinal end 44a remote from tank lid 22, along virtual tube axis R, and snap-locked therein.

[0043] Float valve body 50, which is bell-shaped in the example depicted, is open toward internal tank volume 31 and has, on its outer surface facing radially outward with respect to tube axis R, the same number of protrusions 52 as valve housing 44 has guidance configurations 48 in tube wall 46.

[0044] In the operationally ready state, each protrusion 52 engages into a guidance configuration 48 and thereby secures float valve body 50 on the one hand to prevent rotation around virtual tube axis R and on the other hand to prevent float valve body 50 from falling out of (i.e. being lost from) valve housing 44. Valve housing 44 thus guides float valve body 50, with guidance configurations 48, along a motion path M coincident with tube axis R.

[0045] Guidance configurations 48, which pass completely through tube wall 46 of valve housing 44 in a radial direction, do not extend over the entire axial length of valve housing 44 along virtual tube axis R, but instead end at an axial distance, with respect to virtual tube axis R, before longitudinal end 44a that is remote from tank lid 42. As a consequence, a portion of valve housing 44 which is remote from upper tank shell 12, in particular from tank lid 22, and which preferably contains longitudinal end 44a, is embodied uninterruptedly encirclingly in a circumferential direction around virtual tube axis R.

[0046] As a result of the bell-shaped configuration of float valve body 50, the latter can be deformed easily and with little energy expenditure so that it can be introduced through opening 54 at longitudinal end 44a, remote from tank lid 22, of valve housing 44; and because of its material-related and geometric elasticity it returns to its undeformed position shown in FIG. 1 after passing through opening 54. In this position, protrusions 52 engage behind those longitudinal ends of guidance configurations 48 which are remote from tank lid 22, and thereby positively secure float valve body 50 in valve housing 44.

[0047] In the embodiment depicted, valve housing 44 is embodied in one piece with the tank shell and in one piece overall. A buoyancy body 51 of float valve body 50 is likewise embodied in one piece. It carries, on its side that faces toward valve opening 40 during operation, a valve seal 56 that comes into abutment against a valve seat 58 when operating liquid B rises and moves float valve body 50 toward valve opening 40. Valve seat 58 is a protrusion proceeding annularly around valve opening 44. Valve seat 56 is made of a flexible material, so that it can abut in sealingly deformed fashion against valve seat 58 solely as a result of the buoyancy forces acting during operation on float valve body 50.

[0048] Adjacent to valve opening 40 on the outer side of tank 10 is an attachment fitting 60 that is also embodied in one piece with the tank shell (in this case, upper tank shell 12). A hose or other fluid conduit can be attached to attachment fitting 60 so that gas escaping through valve opening 40 can be discharged in controlled fashion.

[0049] In an alternative embodiment, cavity 62 of the bell-shaped float valve body 50 can be filled with a foamed material. The entire float valve body 50 can be constituted by foamed material. All that is critical is that float valve body 50 have a lower density, with respect to the space occupied by it (including a gas space constituted in cavity 62), than operating liquid B, so that sufficient buoyancy forces can act on float valve body 50 as operating liquid B rises in tank 10.

[0050] Float valve body 50 is shown in FIG. 1 in its operating position, in which valve opening 40 is open to allow gas to flow through out of internal tank volume 31, in particular out of gas space 42. Float valve body 50 is preloaded into this position by gravity. In the absence of buoyancy forces, float valve body 50 is displaced by gravity into the position shown in FIG. 1.

[0051] While considerable emphasis has been placed on the preferred embodiments of the invention illustrated and described herein, it will be appreciated that other embodiments, and equivalences thereof, can be made and that many changes can be made in the preferred embodiments without departing from the principles of the invention. Furthermore, the embodiments described above can be combined to form yet other embodiments of the invention of this application. Accordingly, it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the invention and not as a limitation.