Spool and poppet inlet metering valve

An inlet metering valve system, for metering the flow of liquid fuel in a fuel system for a diesel engine, the inlet metering valve system comprising:

• an inlet opening for coupling to a fuel supply, allowing an incoming flow of the fuel;
• a valve sleeve having a central axial bore for receiving the incoming flow of fuel, and an outlet opening extending outward from the central axial bore;
• a valve seat at a fixed axial location relative to the central axial bore of the sleeve;
• a moveable valve member comprising a spool configured for sliding axial movement within the central axial bore of the valve sleeve, and a poppet valve face formed in a distal end of the moveable valve member for closing off flow of the fuel to the outlet opening of the valve sleeve when the moveable valve member is positioned so that the poppet valve face engages the poppet valve seat;
• wherein movement of the moveable valve member within the central axial bore of the valve sleeve changes the position of the spool relative to the outlet opening of the valve sleeve so as to regulate fuel output, when the moveable valve member is positioned so that the poppet valve fa is out of engagement with the poppet valve seat;
• a solenoid comprising an armature and a winding, wherein the solenoid is coupled to a proximal end of the moveable valve member to axially move the moveable valve member in response to a control current applied to the solenoid;
• flux adjustment means, for adjustably setting flow of magnetic flux during operation of the solenoid;
• and
• a pre-load adjustment means, for adjustably setting a loading force applied to the moveable valve member when the solenoid is not energized.

A liquid flow metering valve system, comprising:

• an inlet opening for allowing an incoming flow of liquid;
• a valve sleeve having a central axial bore for receiving the incoming flow of liquid, a poppet valve seat, and an outlet opening extending outward from the central axial bore to the exterior of the valve sleeve;
• a moveable valve member comprising a spool configured for sliding axial movement within the central axial bore of the valve sleeve, and a poppet valve face formed in a distal end of the moveable valve member, the poppet valve face engaging the poppet valve seat to close off flow of liquid to the outlet opening of the valve sleeve;
• the spool having a lateral bore extending outward from an interior of the spool;
• wherein, when the moveable valve member is positioned so that the poppet valve face is withdrawn from engagement with the poppet valve seat, the lateral bore is aligned with the outlet opening so as to enable flow of liquid to the outlet opening, movement of the moveable valve member within the central axial bore of the valve sleeve changes the position of the spool relative to the outlet opening of the valve sleeve so as to regulate liquid output;
• and
• a solenoid comprising an armature and a winding, wherein the solenoid is coupled to a proximal end of the moveable valve member to axially move the moveable valve member within the central axial bore in response to a control current applied to the solenoid.