Automotive diesel exhaust HC dosing valve for use with diesel particulate filter systems

1. A dosing valve assembly for administering a reducing agent into an exhaust stream from an internal combustion engine upstream of a catalytic converter and a diesel particulate filter, comprising:

a control valve coupled to a source of reducing agent; and

a fluid pressure operated delivery valve constructed and arranged for coupling directly to the exhaust stream at a location upstream of the catalytic converter and the diesel particulate filter, the delivery valve having structure movable from a closed position to an open position to enable a reducing agent to be administered into the exhaust stream, the delivery valve including an inlet communicating with an elongated conduit connecting the control valve and delivery valve for fluidly communicating the reducing agent from the control valve to the delivery valve,

wherein the control valve is coupled to an electronic control unit that signals the control valve to move between an open and closed fluid flow condition in response to feedback of NO x emissions in the exhaust stream,

wherein the delivery valve is a poppet valve having a longitudinal axis and comprising a housing; a movable valve plate disposed generally transversely with respect to the longitudinal axis and having an opening there-through, parallel to and spaced from the longitudinal axis, for the passage of reducing agent; an axially extending valve stem coupled to the valve plate and including a flared portion having a surface disposed at an acute angle with respect to the longitudinal axis, the surface of the flared portion mating with a valve seat surface disposed generally at the same angle as the surface of the flared portion; and a spring for normally biasing the valve plate such that the surface of the flared portion resides against the valve seat surface to prevent reducing agent flow from an outlet of the poppet valve, and

wherein the spring has a force such that fluid pressure alone biases the valve plate against the force of the spring to such that the surface of the flared portion moves away from the valve seat surface to permit reducing agent flow from the outlet of the poppet valve.

2. The dosing valve assembly recited in claim 1 , wherein the delivery valve is a fluid pressure operated poppet valve.

3. The dosing valve assembly recited in claim 1 , wherein the elongated conduit is a connecting tube of a length sufficient to mount the control valve away from a high temperature environment proximal to the exhaust stream.

4. The dosing valve assembly recited in claim 1 , wherein the control valve is an electronic fuel injector.

5. The dosing valve assembly recited in claim 4 , wherein the fuel injector comprises an inlet for coupling to the source of the fuel, electronic means for opening and closing a fluid flow path through the fuel injector, and an outlet for coupling the fuel injector to the elongated conduit.

6. A dosing valve assembly for administering fuel into an exhaust stream from an internal combustion engine upstream of a catalytic converter and a diesel particulate filter, comprising:

an electronic fuel injector coupled to a source of fuel; and

a fluid pressure operated poppet valve constructed and arranged for direct coupling to the exhaust stream at a location upstream of a catalytic converter and a diesel particulate filter, the poppet valve having structure movable from a closed position to an open position to enable fuel to be administered into the exhaust stream, the poppet valve including an inlet communicating with an elongated conduit connecting the electronic fuel injector and poppet valve for fluidly communicating fuel from the electronic fuel injector to the poppet valve,

wherein the fuel injector is coupled to an electronic control unit that signals the fuel injector to move between an open and closed fluid flow condition in response to feedback of NO x emissions in the exhaust stream,

wherein the poppet valve has a longitudinal axis and comprises a housing; a movable valve plate disposed generally transversely with respect to the longitudinal axis and having an opening there-through, parallel to and spaced from the longitudinal axis, for the passage of fuel; an axially extending valve stem coupled to the valve plate and including a flared portion having a surface disposed at an acute angle with respect to the longitudinal axis, the surface of the flared portion mating with a valve seat surface disposed generally at the same angle as the surface of the flared portion; and a spring for normally biasing the valve plate such that the surface of the flared portion resides against the valve seat surface to prevent fuel flow from an outlet of the poppet valve, and

wherein the spring has a force such that fluid pressure alone biases the valve plate against the force of the spring to such that the surface of the flared portion moves away from the valve seat surface to permit reducing agent flow from the outlet of the poppet valve.

7. The dosing valve assembly recited in claim 6 , wherein the elongated conduit is a connecting tube of a length sufficient to mount the fuel injector away from a high temperature environment proximal to the exhaust stream.

8. The dosing valve assembly recited in claim 6 , wherein the fuel injector comprises an inlet for coupling to the source of fuel, electronic means for opening and closing a fluid flow path through the fuel injector, and an outlet for coupling the fuel injector to the elongated conduit.

9. A dosing valve assembly for administering diesel fuel into an exhaust stream from an internal combustion engine upstream of a catalytic converter and a diesel particulate filter, comprising:

a control valve coupled to a source of diesel fuel;

a fluid pressure operated delivery valve constructed and arranged for coupling directly to the exhaust stream, the delivery valve having structure movable from a closed position to an open position to enable diesel fuel to be administered into the exhaust stream upstream of the catalytic converter and diesel particulate filter, the delivery valve including an inlet communicating with an elongated conduit connecting the control valve and delivery valve for fluidly communicating diesel fuel from the control valve to the delivery valve, the elongated conduit displacing the control valve from the fuel delivery valve,

wherein the control valve is coupled to an electronic control unit that signals the control valve to move between an open and closed fluid flow condition in response to feedback of NO x emissions in the exhaust stream,

wherein the delivery valve is a poppet valve having a longitudinal axis and comprising a housing; a movable valve plate disposed generally transversely with respect to the longitudinal axis and having an opening there-through, parallel to and spaced from the longitudinal axis, for the passage of diesel fuel; an axially extending valve stem coupled to the valve plate and including a flared portion having a surface disposed at an acute angle with respect to the longitudinal axis, the surface of the flared portion mating with a valve seat surface disposed generally at the same angle as the surface of the flared portion; and a spring for normally biasing the valve plate such that the surface of the flared portion resides against the valve seat surface to prevent diesel fuel flow from an outlet of the poppet valve, and

wherein the spring has a force such that fluid pressure alone biases the valve plate against the force of the spring to such that the surface of the flared portion moves away from the valve seat surface to permit reducing agent flow from the outlet of the poppet valve.

10. The dosing valve assembly recited in claim 9 , wherein the delivery valve is a fluid pressure operated poppet valve.

11. The dosing valve assembly recited in claim 9 , wherein the elongated conduit is a connecting tube of a length sufficient to mount the control valve away from a high temperature environment proximal to the exhaust stream.

12. The dosing valve assembly recited in claim 9 , wherein the control valve is an electronic fuel injector.

13. The dosing valve assembly recited in claim 12 , wherein the fuel injector comprises an inlet for coupling to the source of diesel fuel, electronic means for opening and closing a fluid flow path through the fuel injector, and an outlet for coupling the fuel injector to the elongated conduit.