Cylinder head arrangement for variable valve actuation rocker arm assemblies

A switching rocker arm responsive to an oil control system to provide variable valve timing, the switching rocker arm comprising:

• an outer arm comprising first and second outer side arms;
• an inner arm comprising first d second inner side arms and a cam-contacting member configured for transferring motion from a lift lobe of a cam to the switching rocker arm, the inner arm disposed between the first and the second outer side arms and the cam-contacting member disposed between the first and second inner side arms;
• a pivot axle securing the inner arm to the outer arm, the pivot axle configured to permit pivoting movement of the inner arm relative to the outer arm about the pivot axle;
• at least one biasing spring secured to the outer arm, the at least one biasing spring in contact with the cam-contacting member;
• a dual feed hydraulic lash adjuster (DFHLA) configured to provide hydraulic switching fluid to the inner arm, wherein the DFHLA comprises a lower lash compensation port fluidly coupled to engine oil pressure, and an upper switching pressure port fluidly coupled to an oil control valve (OCV);
• a latch for selectively securing the inner arm relative to the outer arm thereby selectively, permitting lost motion movement of the inner arm relative to the outer arm about the pivot axle, and wherein a position of the latch is responsive to the hydraulic switching fluid;
• and
• an inner arm sloped surface of the inner arm and a latch sloped surface of the latch configured to provide a smooth latch movement when the inner arm sloped surface contacts the latch sloped surface;
• a pivoting valve pad that contacts and drives a valve stem, wherein the pivoting valve pad is mounted on the pivot axle, and wherein lips formed on the inner arm restrict the pivoting valve pad from rotating about the pivot axle.

A method for operating an oil control system for a latch pin of a variable valve actuation system, the method comprising:

• providing engine oil pressure to a lower lash compensation port of a dual feed hydraulic lash adjuster (DFHLA);
• operating the latch pin of a switching rocker arm between a first position allowing lost motion movement between an inner arm and an outer arm of the switching rocker arm about a pivot axle coupling the inner arm and the outer arm, and a second position preventing lost motion movement between the inner arm and the outer arm of the switching rocker arm about the pivot axle;
• and
• wherein operating the latch pin comprises providing one of a low pressure value or a high pressure value to an upper switching port of the DFHLA, thereby providing hydraulic switching fluid to the switching rocker arm,
• engaging an inner arm sloped surface of the inner arm with a latch pin sloped surface of the latch pin to smoothly disengage the inner arm and the latch pin;
• and
• driving a valve stem through contact with a pivoting valve pad, wherein the pivoting valve pad is mounted on the pivot axle, and wherein lips formed on the inner arm restrict the pivoting valve pad from rotating about the pivot axle.