Fuel rail for gasoline direct injection

Abstract

To obtain, at low cost, a fuel rail that maintains low hardness and good formability before being formed into a tube stock, can be made to form a welded pipe, and has high-strength properties with which the fuel rail can withstand a high fuel pressure even when formed so as to be relatively thin. A fuel rail for gasoline direct injection that is used at a fuel pressure of at least 30 MPa and is formed from an iron-alloy welded pipe. The fuel rail comprises an iron alloy that contains chemical components of C, Si, Mn, P, S, Nb, and Mo. The plate thickness t and the outer diameter D of the fuel rail have a ratio t/D of 0.2 or less. A bainitic structure can be precipitated by brazing the fuel rail in a furnace during manufacturing.

1 . A fuel rail for gasoline direct injection at a fuel pressure of at least 30 MPa, characterized in that it is formed from an iron-alloy welded pipe, wherein the fuel rail comprises an iron alloy that contains chemical components of C, Si, Mn, P, S, Nb, and Mo, wherein the plate thickness t and the outer diameter D of the fuel rail have a ratio t/D of 0.2 or less, and wherein a bainitic structure can be precipitated by copper-brazing the fuel rail in a furnace during manufacturing. 
     
     
         2 . The fuel rail for gasoline direct injection of  claim 1 , characterized in that the fuel pressure is from 30 kPa to 80 kPa.