Motor driven fuel pump having impeller

Abstract

A fuel pump for an internal combustion engine includes a suction-side cover having a fuel inlet, an exhaust-side cover having a fuel outlet, an electric motor, a pump casing disposed between the electric motor and the suction-side cover, an impeller disposed between the suction-side cover and the pump casing to be rotated by the electric motor, and a cylindrical housing for accommodating the suction-side cover, the pump casing and the impeller. The suction-side cover is made of a resinous member that has a shoulder having a round surface in contact with a portion of the cylindrical housing that is clinched at the shoulder.

What is claimed is:  
     
         1 . A fuel pump for supplying fuel to an internal combustion engine comprising a suction-side cover having a fuel inlet, an exhaust-side cover having a fuel outlet, an electric motor disposed between said suction-side cover and said exhaust-side cover, a pump casing disposed between said electric motor and said suction-side cover, a passage member having a pressure boosting passage disposed between said suction-side cover and said pump casing, an impeller disposed in the pressure boosting passage to be rotated by said electric motor, and a cylindrical housing for accommodating said suction-side cover, said pump casing and said impeller, 
 wherein said suction-side cover comprises a resinous member that has a shoulder having a round surface in contact with a portion of said cylindrical housing that is clinched at said shoulder.    
     
     
         2 . The fuel pump as claimed in  claim 1 , wherein said round surface is disposed at a peripheral surface of said suction-side cover away from said pump casing.  
     
     
         3 . The fuel pump as claimed in  claim 2 , wherein the radius of said round corner is 2 mm or longer.  
     
     
         4 . The fuel pump as claimed in  claim 2 , wherein the portion of said cylindrical housing that is clinched has a surface formed by a punch that has a concave pressing surface.  
     
     
         5 . The fuel pump as claimed in  claim 1 , wherein said shoulder has a thickness between 4 mm and 5 mm.  
     
     
         6 . A fuel pump for supplying fuel to an internal combustion engine including a suction-side cover having a fuel inlet, a pump casing, an impeller disposed between said suction-side cover and said pump casing and a cylindrical housing for accommodating said suction-side cover, said pump casing and said impeller, 
 wherein:    said suction-side cover has a shoulder having a round surface in contact with a portion of said cylindrical housing that is clinched at said shoulder;    said round surface has a radius of 2 mm or longer; and    said shoulder has a thickness between 4 mm and 5 mm.