Fuel injector

Patent metadata

Field	Value
Publication number	US-10408176-B2
Application number	US-201615747779-A
Country	US
Kind code	B2
Filing date	Jul 21, 2016
Priority date	Jul 29, 2015
Publication date	Sep 10, 2019
Grant date	Sep 10, 2019

Abstract

A fuel injector includes control valve for controlling fuel pressure in a control chamber. The control valve includes a valve seat; and a valve member having a valve face for cooperating with the valve seat to control fuel pressure in the control chamber. A return line is provided for returning fuel from the control chamber. An armature connected to the valve member and an actuator is provided for actuating the armature. The armature is disposed in an armature chamber. A deflector is provided in the armature chamber to form a first sub-chamber and a second sub-chamber. The first and second sub-chambers are in fluid communication with each other via a first aperture. A pressure differential is established between the first and second sub-chambers when the valve face lifts from the valve seat promoting the flow of fuel from the second sub-chamber into the first sub-chamber through the first aperture.

First claim

The invention claimed is:

1. A fuel injector comprising:
a control valve which controls fuel pressure in a control chamber, the control valve comprising:
a valve seat;
a valve member having a valve face for cooperating with the valve seat to control fuel pressure in the control chamber;
a return line for returning fuel from the control chamber;
an armature connected to the valve member, the armature being disposed in an armature chamber;
an actuator for actuating the armature; and
a deflector disposed in the armature chamber which forms a first sub-chamber and a second sub-chamber, the first sub-chamber and the second sub-chamber being in fluid communication with each other via at least one first aperture;

wherein, in use, a pressure differential is established between the first sub-chamber and the second sub-chamber when the valve face lifts from the valve seat promoting the flow of fuel from the second sub-chamber into the first sub-chamber through the at least one first aperture,
wherein the at least one first aperture is configured to establish communication between radially inner ends of the first sub-chamber and the second sub-chamber,

wherein the at least one first aperture is disposed proximal to the valve seat,
wherein the at least one first aperture has a radial width in the range 0.0325 mm to 0.2825 mm inclusive.

2. A fuel injector as claimed in claim 1 , wherein the at least one first aperture is an annular aperture extending circumferentially around the valve member.

3. A fuel injector as claimed in claim 1 , further comprising at least one second aperture which facilitates circulation between the first sub-chamber and the second sub-chamber.

4. A fuel injector as claimed in claim 3 , wherein the valve seat and the at least one second aperture are formed at opposing ends of the armature chamber.

5. A fuel injector as claimed in claim 4 , wherein the at least one second aperture has a longitudinal dimension of at least 0.05 mm.

6. A fuel injector as claimed claim 1 , wherein the control valve opens into the first sub-chamber; and the second sub-chamber is formed between the deflector and the armature.

7. A fuel injector as claimed in claim 1 , wherein the valve member comprises a longitudinal bore which is open at a first end and a second end.

8. A fuel injector as claimed in claim 7 , wherein the first end of the longitudinal bore opens into a collection chamber; the collection chamber either being closed or connected to the return line.

9. A fuel injector as claimed in claim 7 , wherein the second end of the longitudinal bore opens into a chamber above the armature and at least one third aperture is maintained between the actuator and the armature when the control valve is open.

10. A fuel injector as claimed in claim 9 , wherein the at least one third aperture comprises a clearance between an upper face of the armature and an opposing face of the actuator.

11. A fuel injector as claimed in claim 10 , wherein the clearance between the upper face of the armature and the opposing face of the actuator is between 0.01 mm and 0.06 mm.

12. A fuel injector as claimed in claim 1 , wherein an underside of the deflector is spaced apart from a bottom of the armature chamber by a longitudinal offset in the range 0.3 mm to 0.4 mm.

Assignees

• Delphi Tech Ip Ltd

Inventors

• Coutton Alexandre
• Lesieur Cyrille

Classifications

• F02M63/007

  Details not provided for in, or of interest apart from, the apparatus of the groups F02M63/0014 - F02M63/0059 · CPC title

• F02M63/0017

  using electromagnetic operating means · CPC title

• F02M63/0033

  Lift valves, i.e. having a valve member that moves perpendicularly to the plane of the valve seat · CPC title

• F02M63/0073

  Pressure balanced valves · CPC title

• F02M2200/04

  Fuel-injection apparatus having means for avoiding effect of cavitation, e.g. erosion · CPC title