Control valve assembly and fuel injector incorporating a control valve assembly

Patent metadata

Field	Value
Publication number	US-10267279-B2
Application number	US-201414774299-A
Country	US
Kind code	B2
Filing date	Feb 26, 2014
Priority date	Mar 13, 2013
Publication date	Apr 23, 2019
Grant date	Apr 23, 2019

Abstract

A control valve assembly for controlling fuel pressure in a control chamber of a fuel injector. The control valve assembly comprising a valve member arranged in a bore provided in a valve housing, at least one of the valve member and the valve housing being moveable with respect to the other, wherein the valve member comprises a fuel-receiving cavity arranged to receive fuel that distorts at least a portion of the valve member so as to increase an external dimension thereof.

First claim

The invention claimed is:

1. A control valve assembly for controlling fuel pressure in a control chamber of a fuel injector, the control valve assembly comprising a valve member arranged in a bore provided in a valve housing wherein the valve member moves between a closed position which prevents fluid communication between the control chamber and a low pressure drain and an open position which provides fluid communication between the control chamber and the low pressure drain, at least one of the valve member and the valve housing being moveable with respect to the other, wherein the valve member comprises a fuel-receiving cavity which receives fuel that distorts at least a portion of the valve member so as to increase an external dimension thereof such that the fuel-receiving cavity is in fluid communication with the low pressure drain when the valve member is in the open position and such that the fuel-receiving cavity is not in fluid communication with the low pressure drain when the valve member is in the closed position, wherein the fuel-receiving cavity is a drilled cavity which extends into the valve member from a first end and wherein the drilled cavity is plugged by an insert which prevents fluid communication through the drilled cavity from the fuel receiving cavity to the first end.

2. The control valve assembly of claim 1 , wherein at least one of the valve member and the valve housing is engageable with a valve seating to control fuel pressure within the control chamber, and wherein fuel pressure within the fuel-receiving cavity is variable depending on whether the valve member is engaged with the valve seating.

3. The control valve assembly of claim 1 , wherein the valve member comprises an annular wall surrounding the fuel-receiving cavity, so that fuel received in the fuel-receiving cavity exerts an outward radial force on at least a portion of the annular wall, so as to increase an external diameter thereof.

4. The control valve assembly of claim 1 , wherein the valve member comprises a valve body arranged in a close sliding fit in the bore, and at least a portion of the fuel-receiving cavity extends into the valve body.

5. The control valve assembly of claim 4 , wherein the bore is arranged to receive fuel from a high-pressure fuel supply, and wherein fuel received in the bore acts to distort the valve housing and/or the valve member so as to increase a radial clearance defined between the valve body and a wall of the bore.

6. The control valve assembly of claim 5 , wherein the bore defines a fuel gallery for receiving fuel from the high-pressure fuel supply, and fuel received in the fuel gallery acts to distort the valve housing and/or the valve member so as to increase the radial clearance.

7. The control valve assembly of claim 6 , wherein fuel received in the fuel-receiving cavity acts to distort the valve body so as at least partially to counteract the increase in the radial clearance caused by the fuel received in the bore.

8. The control valve assembly of claim 6 , wherein the fuel-receiving cavity is in fluid communication with the fuel gallery, such that fuel pressure in the fuel-receiving cavity is the same as fuel pressure in the fuel gallery.

9. The control valve assembly of claim 8 , wherein the valve member comprises an inlet in fluid communication with the fuel-receiving cavity and the fuel gallery.

10. The control valve assembly of claim 4 , wherein, when fuel is absent from the bore and the fuel-receiving cavity, the valve body is of substantially constant external diameter.

11. The control valve assembly of claim 1 , wherein at least one of the valve member and the valve housing is moveable with respect to the other between a first position in which the control chamber, the fuel-receiving cavity and a high-pressure fuel supply are arranged in mutual fluid communication, and a second position in which the control chamber is in fluid communication with a low-pressure fuel drain.

12. The control valve assembly of claim 1 , wherein the valve member is moveable with respect to the valve housing.

13. A fuel injector comprising the control valve assembly of claim 1 , a control chamber, and an injection nozzle, the control chamber being arranged to control movement of a valve needle to control the injection of fuel from the injection nozzle.

14. The control valve assembly of claim 11 wherein the control chamber is not in fluid communication with the low-pressure drain in the first position.

15. The fuel injector of claim 13 wherein a position of the valve member relative to the housing determines a pressure within the control chamber and the pressure within the control chamber opens and closes the valve needle.

Assignees

• Delphi Tech Ip Ltd

Inventors

• Sauvetre Ludovic
• Bonneau David
• Barbier Philippe
• Legrand Philippe

Classifications

• F02M63/004

  Sliding valves, e.g. spool valves, i.e. whereby the closing member has a sliding movement along a seat for opening and closing · CPC title

• F02M61/04 Primary

  having valves {, e.g. having a plurality of valves in series} · CPC title

• F02M63/0043

  Two-way valves · CPC title

• F02M61/18

  Injection nozzles, e.g. having valve seats; {Details of valve member seated ends, not otherwise provided for} · CPC title

• F02M63/0078 Primary

  Valve member details, e.g. special shape, hollow or fuel passages in the valve member · CPC title