Closure system on a fuel tank

Abstract

The invention relates to a closure system on a fuel tank ( 1 ) comprising an opening ( 2 ) in the wall of the fuel tank ( 1 ) and a closure cover ( 6 ) which covers the opening ( 2 ) and clamps at least one elastomer seal ( 5 ) between itself and a border of the tank wall enclosing the opening ( 2 ), the elastomer seal ( 5 ) being formed as a multilobed sealing cord or multilobed sealing ring surrounding the opening ( 2 ), in such a way that it forms a number of sealing lips ( 11 ) that are spaced apart from one another, at least two spaced-apart sealing lips ( 11 ) of the elastomer seal ( 5 ) consisting of different materials, one of which is impermeable to hydro carbons and a second is impermeable to alcohol-containing media or alcohol-containing additives.

1 . Closure system on a fuel tank comprising an opening in the wall of the fuel tank and a closure cover which covers the opening and clamps at least one elastomer seal between itself and a border of the tank wall enclosing the opening, wherein the elastomer seal is formed as a multilobed sealing cord or multilobed sealing ring surrounding the opening, in such a way that it forms a number of sealing lips that are spaced apart from one another, at least two spaced-apart sealing lips of the elastomer seal consisting of different materials, one of which is substantially impermeable to hydrocarbons and a second is substantially impermeable to alcohol-containing media or alcohol-containing additives wherein the the elastomer seal has an approximately H-shaped cross-sectional profile with a first limb and a second limb and with a crosspiece connecting the limbs, the limbs respectively consisting of different elastomeric materials, characterized in that the crosspiece connecting the limbs consisting of a thermoplastic material. 
     
     
         2 . Closure system according to  claim 1 , characterized in that a first material is a fluoroelastomer and a second material is an NBR or an HNBR. 
     
     
         3 . Closure system according to  claim 1 , characterized in that the sealing lips enclose between them a diffusion barrier in the form of an air gap. 
     
     
         4 . Closure system according to  claim 1 , characterized in that the elastomer seal has in cross section an X, K or H profile. 
     
     
         5 . Closure system according to  claim 1 , characterized in that the elastomer seal comprises a supporting body, on which at least two sealing lips of different elastomeric materials are integrally formed. 
     
     
         6 . Closure system according to  claim 5 , characterized in that the supporting body consists of a non-elastomeric material, preferably of thermoplastic material. 
     
     
         7 . (canceled) 
     
     
         8 . Closure body according to  claim 1 , characterized in that the crosspiece consists of POM or PA. 
     
     
         9 . Closure system according to  claim 1 , characterized in that, in the fitted position, the spaced-apart sealing lips of the elastomer seal are arranged one behind the other in the circumferential direction of the opening.