Fuel injection valve coated with anti-fouling perfluoropolyether fim layer and associated method, and direct injection engine using same

A fuel injection valve coated with an organic layer of film on the surface of its fuel injection port, wherein said organic film of layer comprises a perfluoropolyether compound as defined in the following chemical compound 1,

• F—(CXF2XO)n—A or A—{(CXF2XO)n}—A, (Comp. 1)
• wherein X is an integer from 1 to 3 which may differ upon repetition, n is a value at which a numeric average molecular weight of —(CXF2XO)n— becomes 2000 or more, and A is a residue.

A fuel injection valve coated with an organic layer of film on the surface of its fuel injection port, wherein said organic layer of film comprises a perfluoropolyether compound as defined in the following chemical compound 2

• F—(CXF2XO)n—C2F4—B or B—{—(CXF2XO)n}—B, (Comp. 2)
• wherein X is an integer from 1 to 3 which may differ upon repetition, n is a value at which a numeric average molecular weight of —(CXF2XO)n— becomes 2000 or more, and B is a residue of alkoxy silane group.

A fuel injection valve coated with an organic layer of film on the surface of its fuel injection port, wherein said organic layer of film comprises forming a layer of perfluoropolyether compounds 1 or 2 on the surface thereof via a bonding acceleration layer which is an organic polymer film or an oxide film, wherein

• F—(CXF2XO)n—A or A—{(CXF2XO)n}—A, (Comp. 1) F—(CXF2XO)n—C2F4—B or B—{—(CXF2XO)n}—B, (Comp. 2)
• and wherein X is an integer from 1 to 3 which may differ upon repetition, n is a value at which a numeric average molecular weight of —(CXF2XO)n— becomes 2000 or more, A is a residue, and B is a residue of alkoxy silane group.

A fuel injection valve having an organic film coating, which has a thickness in a range from 1.5 nm to 30 nm, on the surface of its fuel injection port and its vicinity.

A fuel injection valve having an organic film coated on the surface of its fuel injection port, wherein said fuel injection port has a nozzle which is capable of atomizing fuel into a particle size of 20 μm or less.

A fuel injection valve having an organic film coated on the surface of its fuel injection port, wherein said fuel injection port is 0.3-0.8 mm in diameter.

A fuel injection valve having an organic film coated on the surface of its fuel injection port, wherein said fuel injection port and a portion in the vicinity thereof comprise a kind of ferrite stainless steel which includes 0.6-1.5 wt % of C, 1 wt % or less of Si, 1.5 wt % or less of Mn and 15-20 wt % of Cr.

A direct injection engine having a cylinder head with air intake means and exhaust means provided in a combustion chamber, a piston reciprocating in said cylinder, fuel injection means which is provided for injecting fuel into said combustion chamber such that fuel is atomized to have an air/fuel ratio of 45 or greater suitable for a lean burn control, and ignition means for igniting atomized fuel from said fuel injection means, wherein said fuel injection means comprises an organic film coated on the surface of its fuel injection port and a portion in the vicinity thereof.

A direct injection engine having a cylinder head with air intake means and exhaust means provided in a combustion chamber, a piston reciprocating in said cylinder, fuel injection means which is provided for injecting fuel into said combustion chamber such that fuel is atomized to have an air/fuel ratio of 45 or greater suitable for a lean burn control, and ignition means for igniting atomized fuel from said fuel injection means, wherein said port and its vicinity in the vicinity comprise a kind of ferrite stainless steel including 0.6-1.5 weight % of C, less than 1 weight % of Si, less than 1.5 weight % of Mn, and 15-20 weight % of Cr, wherein said injection port is 0.3-0.8 mm of diameter, capable of atomizing fuel whose particle size is less than 20 μm, and wherein a thickness of said organic layer of film provided on the surface of said injection port and its vicinity is 1.5-10 nm.