Feed unit for feeding fuel out of a fuel tank

Abstract

A feed unit ( 2 ) for feeding fuel out of a fuel tank ( 1 ) has a baffle ( 4 ) having two chambers ( 7, 13 ) which are connected to each other via a valve ( 14 ) designed as a throttle valve. A fuel pump ( 5 ) projects with a suction opening ( 6 ) into the first chamber ( 7 ). When the fuel tank ( 1 ) is emptied, the first chamber ( 7 ) is emptied. Over a period of time dependent on the throttling of the valve ( 14 ) fuel flows out of the second chamber ( 13 ) into the first chamber ( 7 ) and covers the suction opening ( 6 ). This ensures that, after the period of time, the fuel pump ( 5 ) can suck up fuel.

1 . A feed unit for feeding fuel out of a fuel tank of a motor vehicle, having a baffle ( 4 ) which has a first chamber for collecting fuel, having a fuel pump for sucking up fuel and having a fuel-pump suction opening arranged in the vicinity of the bottom of the first chamber of the baffle, characterized in that a second chamber ( 13 ) is connected to the first chamber ( 7 ) via a valve ( 14 ), and in that the valve ( 14 ) is a throttle valve, with the volumetric flow of fuel that is restricted by the valve ( 14 ) being smaller than the volumetric flow fed by the fuel pump ( 5 ).  
   
   
       2 . The feed unit as claimed in  claim 1 , characterized in that the second chamber ( 13 ) is manufactured integrally with the baffle ( 4 ).  
   
   
       3 . The feed unit as claimed in  claim 1  or  2 , characterized in that the chambers ( 7 ,  13 ) are arranged at the same height.  
   
   
       4 . The feed unit as defined in  claim 1 , wherein the valve ( 14 ) is arranged in a common wall ( 12 ) of the first chamber ( 7 ) and of the second chamber ( 13 ).  
   
   
       5 . The feed unit as defined in  claim 1  or  3 , wherein the second chamber ( 13 ) is designed as an annular chamber surrounding the first chamber ( 7 ).  
   
   
       6 . The feed unit as defined in  claim 1  or  6 , wherein the second chamber ( 13 ) is arranged within the baffle ( 4 ) and the common wall ( 12 ) between the first chamber ( 7 ) and the second chamber ( 13 ) is lower than an outer wall ( 15 ) of the baffle ( 4 ).  
   
   
       7 . The feed unit as defined in  claim 1  or  6 , wherein the valve ( 14 ) is designed as an opening with a designated cross section.  
   
   
       8 . The feed unit as defined in  claim 1 , wherein the valve ( 14 ) throttles the volumetric flow, which flows from the second chamber ( 13 ) into the first chamber ( 7 ), in such a manner that the level is equalized in three to five minutes after the fuel pump ( 5 ) has stopped.  
   
   
       9 . The feed unit as defined in  claim 1 , wherein the second chamber ( 13 ) has a volume of approximately 10-20% of the baffle volume.