Steel fuel conveying pipe

• US 9,012,031 B2
• Filed: 07/05/2011
• Issued: 04/21/2015
• Est. Priority Date: 07/23/2010
• Status: Active Grant

• Current Assignee: Usui Kokusai Sangyo Kaisha Limited
• Original Assignee: Usui Kokusai Sangyo Kaisha Limited
• Inventors: Takagi, Kazuo
• Primary Examiner(s): Zimmerman, John J
• Application Number:
  US13/805,437
• Publication Number:
  US 20130098496A1
• Time in Patent Office: 1,386 Days
• Field of Search: None
• US Class Current: 428/614
• CPC Class Codes: F02M 2200/05 Fuel-injection apparatus having means for preventing corrosion
• CPC Class Codes: F02M 2200/9038 Coatings
• CPC Class Codes: F02M 55/02 Conduits between injection pumps and injectors , e.g. conduits between pump and common-rail or conduits between common-rail and injectors
• CPC Class Codes: F16L 58/08 by metal
• CPC Class Codes: F16L 9/02 of metal F16L9/16 - F16L9/22 take precedence
• CPC Class Codes: Y10T 428/12486 Laterally noncoextensive components [e.g., embedded, etc.]
• CPC Class Codes: Y10T 428/12799 Next to Fe-base component [e.g., galvanized]
• CPC Class Codes: Y10T 428/12937 Co- or Ni-base component next to Fe-base component

Abstract

To provide a steel fuel conveying pipe which has high resistance to corrosive fuel and maintains reliability without damaging a direct-injection engine, and connects a high-pressure pump and a direct-injection rail with each other in a gasoline direct-injection engine system, and a fuel conveying pipe suitable as a bypass pipe for coupling direct-injection rails with each other in a V-type gasoline engine. A steel fuel conveying pipe for conveying gasoline is characterized in that a Ni-plated layer is provided on the whole inner circumferential face of the fuel conveying pipe, and an anti-rust film layer composed of a Zn-plated layer and a Zn-based alloy-plated layer is further provided on the Ni-plated layer at at least one end of the fuel conveying pipe.

Claims

1. A steel fuel conveying pipe for conveying gasoline, the pipe having opposite inner and outer circumferential surfaces and opposite ends, the pipe further comprising:

a Ni-plated layer with a thickness of 1 to 15 μ

m provided on all of the inner circumferential surface of the fuel conveying pipe,

an anti-rust film layer consisting essentially of a Zn-plated layer or a Zn-based alloy-plated layer provided on the Ni-plated layer at least at one end of the fuel conveying pipe, the anti-rust film layer having a thickness in a range of 0.1 to 8 μ

m, and when an inner diameter of the fuel conveying pipe is D mm, the anti-rust film layer being provided only up to a position of D to 6D mm from the end of the fuel conveying pipe inward, and

at least a portion of the outer circumferential surface of the fuel conveying pipe being covered with a Zn-plated layer or a Zn-based alloy-plated layer.

4. The steel fuel conveying pipe of claim 1, wherein the fuel conveying pipe is a bypass pipe which couples direct-injection rails with each other in a V-type gasoline engine.

7. The steel fuel conveying pipe of claim 1, wherein the Zn-plated layer or the Zn-based alloy-plated layer is not provided on the Ni-plated layer at positions more than 6D mm from either of the ends of the fuel conveying pipe.

2. A steel fuel conveying pipe for conveying gasoline, the pipe having opposite inner and outer circumferential surfaces and opposite ends, the pipe further comprising:

a Ni-plated layer with a thickness of 1 to 15 μ

m provided on all of the inner circumferential surface of the fuel conveying pipe,

an anti-rust film layer consisting essentially of a Zn-plated layer or a Zn-based alloy-plated layer provided on the Ni-plated layer at an end on a side of gasoline inflow in the fuel conveying pipe, the anti-rust film layer having a thickness in a range of 0.1 to 8 μ

m, and when an inner diameter of the fuel conveying pipe is D mm, the anti-rust film layer being provided only up to a position of D to 6D mm from the end of the fuel conveying pipe inward, and

at least a portion of the outer circumferential surface of the fuel conveying pipe being covered with a Zn-plated layer or a Zn-based alloy-plated layer.

5. The steel fuel conveying pipe of claim 2, wherein the fuel conveying pipe is a bypass pipe which couples direct-injection rails with each other in a V-type gasoline engine.

8. The steel fuel conveying pipe of claim 2, wherein the Zn-plated layer or the Zn-based alloy-plated layer is not provided on the Ni-plated layer at positions more than 6D mm from the inflow ends of the fuel conveying pipe to the end of the fuel conveying pipe opposite the inflow end.

3. A steel fuel conveying pipe for conveying gasoline, the pipe having opposite inner and outer circumferential surfaces and opposite ends, the pipe further comprising:

a Ni-plated layer with a thickness of 1 to 15 μ

m provided on all of the inner circumferential surface of the fuel conveying pipe,

an anti-rust film layer consisting essentially of a Zn-plated layer or a Zn-based alloy-plated layer provided on the Ni-plated layer at both ends on sides of gasoline inflow and gasoline outflow in the fuel conveying pipe, the anti-rust film layer having a thickness in a range of 0.1 to 8 μ

m, and when an inner diameter of the fuel conveying pipe is D mm, the anti-rust film layer being provided only up to a position of D to 6D mm from the end of the fuel conveying pipe inward, and

at least a portion of the outer circumferential surface of the fuel conveying pipe being covered with a Zn-plated layer or a Zn-based alloy-plated layer.

6. The steel fuel conveying pipe of claim 3, wherein the fuel conveying pipe is a bypass pipe which couples direct-injection rails with each other in a V-type gasoline engine.

9. The steel fuel conveying pipe of claim 3, wherein the Zn-plated layer or the Zn-based alloy-plated layer is not provided on the Ni-plated layer at positions more than 6D mm from either of the ends of the fuel conveying pipe.