Electro-valve for discharging common rail

Patent metadata

Field	Value
Publication number	US-9297472-B2
Application number	US-201214126009-A
Country	US
Kind code	B2
Filing date	Jun 13, 2012
Priority date	Jun 15, 2011
Publication date	Mar 29, 2016
Grant date	Mar 29, 2016

Abstract

An electro-valve for discharging a common rail while maintaining a minimum pressure, comprising an electro-magnetic coil inside which is arranged a movable plunger, controlling the displacements of a movable axis engaging a ball valve, said movable plunger being urged in the closing position of the ball valve by a spring housed inside a bearing cap, wherein a bottom wall of the bearing cap surrounds an external surface of the movable plunger, wherein a clearance between the external surface of the plunger and an internal wall of the bearing cap is filled with a film of fuel, the opening movement of the plunger causing the fuel to flow from a room situated on top of the plunger to a bore in which the axis is arranged, wherein a sleeve of a controlled thickness is arranged around the plunger within the clearance to set the thickness of said film of fuel.

First claim

The invention claimed is:

1. An electro-valve for discharging a common rail while maintaining a minimum pressure, comprising an electro-magnetic coil inside which is arranged a bearing cap and a movable plunger, said movable plunger controlling the displacements of a movable axis engaging a ball or needle, said movable plunger not fixed to said movable axis but being urged by a spring housed inside the bearing cap toward said movable axis, wherein the bearing cap surrounds an external surface of the movable plunger so that said movable axis floats between an open and closed state, and wherein a clearance between the external surface of the plunger and an internal wall of the bearing cap is filled with a film of fuel, the opening movement of the plunger causing the fuel to flow from a room situated on top of the plunger to a bore in which the axis is arranged, wherein a sleeve of a controlled thickness is arranged around the plunger within the clearance to set the thickness of said film of fuel, the pressure being controlled by the association of the ball or needle with a seat of the valve characterized in that the sleeve is arranged against the external surface of the plunger, wherein a passage between the external surface of the sleeve and the internal wall of the bearing cap constitutes a restricted passage for a flow of fuel between the room and the bore, or wherein the sleeve is arranged against the internal surface of the bearing cap, wherein a passage between the internal surface of the sleeve and the external wall of the plunger constitutes a restricted passage for a flow of fuel between the room and the bore.

2. An electro-valve according to claim 1 , wherein a conduit drilled through the plunger constitutes a second restricted passage regulating the flow of fuel.

3. An electro-valve according to claim 1 , wherein an additional drilling is provided through a valve body from a seat cavity of the valve to a plunger cavity.

4. An electro-valve according to claim 1 , wherein the spring causes the plunger to rest against an end of the axis to urge the axis in a closing position of the valve.

5. An electro-valve according to claim 1 , in which the sleeve comprises a coating on the surface of the plunger or on the surface of the bearing cap.

Assignees

• Marechal Michel
• Sauvage Frederic
• Cardon Christophe
• Delphi Int Operations Luxembourg Sarl

Inventors

• Marechal Michel
• Sauvage Frederic
• Cardon Christophe

Classifications

• F02M63/025

  from the common rail · CPC title

• F02M61/12 Primary

  characterised by the provision of guiding or centring means for valve bodies · CPC title

• F16K31/0658 Primary

  Armature and valve member being one single element · CPC title

• F02M63/0225

  Fuel-injection apparatus having a common rail feeding several injectors (F02M63/0003 takes precedence); Means for varying pressure in common rails; Pumps feeding common rails · CPC title

• F02M63/0015

  electrical, e.g. using solenoid · CPC title