Evaporative emissions fuel system

Abstract

An engine includes a fuel tank including a fuel tank body defining an internal fuel tank volume for containing a fuel, an air cleaner system including an air cleaner housing defining an internal air cleaner volume, a vent conduit integrally formed with the fuel tank body, the vent conduit extending between an inlet aperture and an outlet aperture, wherein the inlet aperture is in fluid communication with the internal fuel tank volume and the outlet aperture is in fluid communication with the internal air cleaner volume.

What is claimed is: 
     
         1 . An engine, comprising:
 a fuel tank including a fuel tank body defining an internal fuel tank volume for containing a fuel;   an air cleaner system including an air cleaner housing defining an internal air cleaner volume;   a vent conduit integrally formed with the fuel tank body, the vent conduit extending between an inlet aperture and an outlet aperture, wherein the inlet aperture is in fluid communication with the internal fuel tank volume and the outlet aperture is in fluid communication with the internal air cleaner volume.   
     
     
         2 . The engine of  claim 1 , wherein the engine does not include an activated carbon filter for filtering fuel vapor emanating from the internal fuel tank volume. 
     
     
         3 . The engine of  claim 1 , wherein a cross-section of the vent conduit is constant along a length of the vent conduit, wherein the length extends between the inlet aperture and the outlet aperture. 
     
     
         4 . The engine of  claim 1 , wherein a cross-section of the vent conduit varies along a length of the vent conduit, wherein the length extends between the inlet aperture and the outlet aperture. 
     
     
         5 . The engine of  claim 1 , wherein the vent conduit extends outward from the fuel tank body to the air cleaner housing. 
     
     
         6 . The engine of  claim 1 , further comprising an air filter positioned in the internal air cleaner volume. 
     
     
         7 . The engine of  claim 6 , wherein the air filter defines a dirty side and a clean side of the internal air cleaner volume and the outlet aperture of the vent conduit is positioned within the dirty side of the internal air cleaner volume. 
     
     
         8 . The engine of  claim 1 , wherein the fuel tank body comprises:
 a top portion including a filler neck extending along a filler neck axis that is angled relative to a vertical axis, and a top portion mounting surface perpendicular to the filler neck axis;   a bottom portion including a bottom portion mounting surface perpendicular to the filler neck axis;   wherein the top portion is attached to the bottom portion with the top portion mounting surface engaging the bottom portion mounting surface.   
     
     
         9 . The engine of  claim 8 , wherein the filler neck defines a filler neck internal volume and the inlet aperture of the vent conduit opens to the filler neck internal volume. 
     
     
         10 . The engine of  claim 8 , wherein the vent conduit is integrally formed with the top portion of the fuel tank body. 
     
     
         11 . The engine of  claim 1 , wherein the fuel tank body includes a filler neck defining a filler neck internal volume and the inlet aperture of the vent conduit opens to the filler neck internal volume. 
     
     
         12 . The engine of  claim 1 , wherein the vent conduit is integrally formed with the fuel tank body via a gas-assist process during injection molding of the fuel tank body. 
     
     
         13 . A fuel tank, comprising:
 a top portion including a filler neck extending along a filler neck axis that is angled relative to a vertical axis, and a top portion mounting surface perpendicular to the filler neck axis; and   a bottom portion including a bottom portion mounting surface perpendicular to the filler neck axis;   wherein the top portion is attached to the bottom portion with the top portion mounting surface engaging the bottom portion mounting surface.   
     
     
         14 . The fuel tank of  claim 13 , wherein the top portion mounting surface and the bottom portion mounting surface are welded together to attach the top portion to the bottom portion. 
     
     
         15 . The fuel tank of  claim 13 , wherein the top portion mounting surface is formed as a flange and the bottom portion mounting surface is formed as a flange. 
     
     
         16 . The fuel tank of  claim 13 , wherein the top portion defines a top portion internal volume and the bottom portion defines a bottom portion internal volume greater than the top portion internal volume. 
     
     
         17 . The fuel tank of  claim 16 , further comprising:
 a vent conduit integrally formed with the top portion, the vent conduit extending between an inlet aperture formed in the filler neck and an outlet aperture to provide fluid communication between the filler neck and an air cleaner assembly   
     
     
         18 . The fuel tank of  claim 17 , the vent conduit is integrally formed with the top portion via a gas-assist process during injection molding of the top portion. 
     
     
         19 . The fuel tank of  claim 13 , wherein the top portion mounting surface and the bottom portion mounting surface are welded together to attach the top portion to the bottom portion; and
 wherein the top portion mounting surface is formed as a flange and the bottom portion mounting surface is formed as a flange.   
     
     
         20 . The fuel tank of  claim 13 , wherein the top portion mounting surface is formed as a flange and the bottom portion mounting surface is formed as a flange; and
 wherein the top portion defines a top portion internal volume and the bottom portion defines a bottom portion internal volume greater than the top portion internal volume.