METHOD AND SYSTEM FOR VARIABLE CAM TIMING DEVICE

摘要

Methods and systems are described for an engine with a cam torque actuated variable cam timing phaser. Phaser positioning control is improved by reducing inaccuracies resulting from inadvertent spool valve and/or phaser movement when the spool valve is commanded between regions. In addition, improved spool valve mapping is used to render phaser commands more consistent and robust.

主权项

1. A method for an engine, comprising:
in response to a desired cam timing at a mid-lock position with a locking pin engaged, moving a spool valve to move a cam timing phaser to a position advanced of the mid-lock position; holding the phaser at the position advanced of the mid-lock position; and then moving the spool valve to a detent region while a cam torsional pulse occurs.