Apparatus and method for evaluating fuel injectors

• US 7,197,918 B2
• Filed: 08/14/2003
• Issued: 04/03/2007
• Est. Priority Date: 08/14/2003
• Status: Expired due to Term

• Current Assignee: International Engine Intellectual Property Company, LLC (Volkswagen AG)
• Original Assignee: International Engine Intellectual Property Company, LLC (Volkswagen AG)
• Inventors: Shen, Yunbiao
• Primary Examiner(s): MCCALL, ERIC SCOTT
• Application Number:
  US10/641,379
• Publication Number:
  US 20050034514A1
• Time in Patent Office: 1,328 Days
• Field of Search: 731/16, 731/181, 731/19.A, 731/172, 731/173, 731/19.R, 731/12, 731/13, 731/15, 701/104
• US Class Current: 73/114.51
• CPC Class Codes: F02M 65/00 Testing fuel-injection apparatus, e.g. testing injection timing testing of ignition F02P17/00; measuring fuel consumption G01F9/00; Cleaning of fuel-injection apparatus
• CPC Class Codes: G01M 15/00 Testing of engines

Abstract

An apparatus and method for measuring the pressure of a fluid near discharge ports 409 in a nozzle 213 of a fuel injector 201 are described. A fuel injector 201 is charged with fluid from a fluid tank 203 by a fuel pump 205. Upon activation of the fuel injector 201, the fluid is discharged from the nozzle 213. Fluid pressure in the nozzle 213 is communicated to a pressure sensor 215 through an orifice 411 in the nozzle 213. The pressure sensor 215 measures fluid pressure near the discharge ports 409 during fuel injector 201 operation.

Claims

1. A fuel injector for an internal combustion engine comprising:

a nozzle disposed at a distal end of the fuel injector and having at least one discharge port;

a needle slideably mounted inside the fuel injector and the nozzle;

a fluid cavity disposed in the nozzle;

a pressure sensor arranged to measure pressure in the fluid cavity; and

an orifice disposed in the needle and disposed along an outer boundary of the fluid cavity, wherein the pressure sensor is disposed in the orifice.

2. The apparatus of claim 1, wherein the pressure sensor is a piezoelectric quartz transducer.

3. A method comprising the steps of:

charging a fuel injector for an internal combustion engine with fluid;

discharging the fluid from at least one discharge port in a nozzle disposed at a distal end of the fuel injector;

communicating fluid to a pressure sensor through a first orifice disposed in the nozzle;

communicating fluid to the pressure sensor through a second orifice in a needle inside the nozzle of the fuel injector; and

measuring fluid pressure near the at least one discharge port with the pressure sensor.

4. The method of claim 3, further comprising the step of containing the fluid discharged from the nozzle in a chamber.

5. The method of claim 4, further comprising the step of controlling the operating pressure of the chamber.

6. The method of claim 3, further comprising the step of measuring the fluid discharge rate after each discharge of fluid from the nozzle of the fuel injector.

7. The method of claim 3, wherein the pressure sensor is a piezoelectric quartz transducer.