Electrohydraulic valve for controlling a cam shaft phasing mechanism of an internal combustion engine

An electrohydraulic valve for controlling an internal combustion engine, said electrohydraulic control valve comprising:

• a tubular valve body having a longitudinal bore there through forming an outlet port at one end of the valve body, and having with a first port, a second port and an inlet port extending transversely through the body in communication with the longitudinal bore;
• a spool slidably received within the bore of the valve body and having an aperture extending from an end of the spool that is proximate to the one end of the valve body to a point proximate an opposite end of the spool, the spool including an notch in an exterior surface;
• a spring biasing the spool away from the one end of the valve body;
• and
• an actuator having a solenoid coil wound on an annular bobbin with a tube of an electrically conductive, non-magnetic metal within the bobbin, a first pole piece extends into one end of the tube and has a first aperture, a second pole piece extends into another end of the tube and has a second aperture, the actuator further including a first bushing in the first aperture and a second bushing in the second aperture, each of the first and second bushings having a tubular body with a first end section that has a larger outer diameter than a second end section and wherein the second end section that has a smaller inner diameter than the first end section, the actuator additionally having an armature slidably received in the first and second bushings and engaging the spool;
• wherein in response to forces from the spring and the armature, the spool moves into a first position where a first fluid path is provided between the second port and the outlet port and where the notch provides a second fluid path between the first port and the inlet port, and a second position where the notch provides a third fluid path fluid path between the inlet port and the second port and where the aperture provides a fourth between the first port and the outlet port.

An electrohydraulic valve for controlling an internal combustion engine, said electrohydraulic control valve comprising:

• a tubular valve body having a longitudinal bore there through forming an outlet port at one end of the valve body, and having with a first port, a second port and an inlet port extending transversely through the body in communication with the longitudinal bore;
• a spool slidably received within the bore of the valve body and having an aperture extending from an end of the spool that is proximate to the one end of the valve body to a point proximate an opposite end of the spool, the spool including an notch in an exterior surface;
• a spring biasing the spool away from the one end of the valve body;
• and
• an actuator having a solenoid coil wound on an annular bobbin with a tube of an electrically conductive, non-magnetic metal within the bobbin, a first pole piece extends into one end of the tube and has a first aperture, a second pole piece extends into another end of the tube and has a second aperture, the actuator further including a first bushing in the first aperture and a second bushing in the second aperture, each of the first and second bushings having a tubular body with a first end section that has a larger outer diameter than a second end section and wherein the second end section that has a smaller inner diameter than the first end section, the actuator additionally having an armature is slidably received in the first and second bushings and engaging the spool;
• a metal housing around the actuator and secured to the valve body;
• and
• an enclosure of a plastic extending between the metal housing and the actuator and hermetically sealed to the bobbin;
• wherein in response to forces from the spring and the armature, the spool moves into a first position where a first fluid path is provided between the second port and the outlet port and where the notch provides a second fluid path between the first port and the inlet port, and a second position where the notch provides a third fluid path fluid path between the inlet port and the second port and where the aperture provides a fourth between the first port and the outlet port.