Fuel injector with pressurized fuel reverse flow check valve

• US 6,517,011 B1
• Filed: 06/13/2000
• Issued: 02/11/2003
• Est. Priority Date: 06/13/2000
• Status: Expired due to Fees

• Current Assignee: Caterpillar Incorporated
• Original Assignee: Caterpillar Incorporated
• Inventors: Tian, Ye, Ayanji, Sudhindra K.
• Primary Examiner(s): Yuen, Henry C.
• Assistant Examiner(s): Nguyen, Dinh Q.
• Application Number:
  US09/593,027
• Time in Patent Office: 973 Days
• Field of Search: 239/124, 239/88-92, 239/533.1, 239/533.11, 239/96, 137/516.15, 137/516.17, 137/533, 137/533.17, 123/467, 123/470
• US Class Current: 239/124
• CPC Class Codes: F02M 57/02 Injectors structurally combined with fuel-injection pumps
• CPC Class Codes: F02M 57/025 hydraulic, e.g. with pressure amplification
• CPC Class Codes: F02M 59/462 Delivery valves
• CPC Class Codes: Y10T 137/7913 Guided head

Abstract

A fuel injector pressurizes fuel in a pressurization chamber and ejects the fuel from an orifice. A reverse flow check valve allows fluid communication between the pressurization chamber and the orifice during fuel injection, but blocks fluid communication between the pressurization chamber and the orifice when fuel pressure in the pressurization chamber decreases.

Claims

1. A fuel injector comprising:

a pressurization section at least partially defining a variable-volume pressurization chamber;

a nozzle section having a check bore, a nozzle chamber, an orifice, a fuel injection check extending into the nozzle chamber and being slidably disposed in the check bore between a first position that blocks fluid communication between the nozzle chamber and the orifice and a second position that opens fluid communication between the nozzle chamber and the orifice, and a reverse flow check valve fluidly connected with the nozzle chamber; and

a fuel passage fluidly connecting the pressurization chamber in the pressurization section with the reverse flow check valve in the nozzle section,

the reverse flow check valve including a perforated reverse flow check hydro-pneumatically movable between an open position that allows fluid communication from the fuel passage to the nozzle chamber and a closed position that denies fluid communication from the nozzle chamber to the fuel passage; and

wherein the fuel injection check extends through a perforation in the reverse flow check valve.

2. The fuel injector of claim 1, wherein the reverse flow check is ring-shaped.

3. The fuel injector of claim 1, the reverse flow check valve further including a clearance between the reverse flow check and the fuel injection check.

4. The fuel injector of claim 3, wherein said clearance fluidly connects the pressurization chamber with the nozzle chamber when the reverse flow check is in said open position.

5. The fuel injector of claim 1, wherein the reverse flow check is ring-shaped with a central perforation, and a column extends through the central perforation in the reverse flow check.

6. The fuel injector of claim 5, wherein said central perforation includes a clearance between the column and the reverse flow check that fluidly connects the pressurization chamber with the nozzle chamber when the reverse flow check is in said open position.