Double action single valve EEGR
AssigneeSiemens Canada Limited
InventorsKwang Yew, John Edward Cook
Life of this patent
Estimating the term…
Abstract
An EGR valve has two coaxial valve rings that are sequentially opened when the EGR valve is operated. A first, smaller gap is formed by the first valve ring opening and a second larger gap is formed when the first valve ring moves with respect to the second valve ring. In this manner, a nonlinear flow rate is provided through the EGR valve that permits greater accuracy of control at lower exhaust gas flow rates.
Claims13
An EGR valve for an automotive internal combustion engine comprising:
- a valve body;
- an armature;
- an electric coil substantially surrounding the armature and configured to drive the armature in a first direction with respect to the valve body;
- a valve pintle having a longitudinal axis substantially parallel to the first direction, the valve pintle including a valve shaft with a first longitudinal end configured to engage and be driven by armature, and a second longitudinal end having a frusto-conical first valve sealing surface;
- a valve ring having a frusto-conical first valve seat configured to sealingly engage the first valve sealing surface and having a frusto-conical second valve sealing surface on an outer surface thereof;
- a second valve ring fixedly mounted to the valve body and having a frusto-conical second valve seat configured to sealingly engage the second valve sealing surface;
- and,
- a valve ring support slidingly supported on and coaxial with the valve shaft and having a ring supporting surface abutting the valve ring, wherein the ring supporting surface and the frusto-conical first valve sealing surface cooperate to support the valve ring on the end of the pintle.
A method of operating an EGR valve having a first circular valve sealing surface engageable with a first circular valve seat and a second circular valve sealing surface engageable with a second circular valve seat, wherein the first sealing surface and first valve seat are concentric and have substantially the same first diameter and the second sealing surface and the second valve seat are concentric and have substantially the same second diameter larger than the first diameter, the method comprising the steps of:
- spring tensioning the first valve sealing surface and the first valve seat together in a closed position;
- spring tensioning the second valve sealing surface and the second valve seat together in the closed position;
- moving the first valve sealing surface in a first direction away from the first valve seat while holding the first valve seat stationary to create a first annular valve opening between the first valve sealing surface and the second valve seat from the closed position to a first position;
- simultaneously moving the first valve sealing surface, the first valve seat, and the second valve sealing surface together in the first direction from the first position to a second position while holding the first annular opening constant to create a second annular valve opening between the first valve sealing surface and the second valve sealing surface.
Dependencies are inferred from the claim text.