| 摘要 |
PURPOSE:To prevent deviation of the valve timing due to the force applied from a cam, by fixing a motor by a hold signal after rotation of the motor is completed in an apparatus for controlling the valve timing by the rotation of a step motor. CONSTITUTION:An inner sleeve 36 on the side of a cam shaft 18 and an outer sleeve 38 on the side of a timing pulley 28 are respectively formed with slits 40, 42, and roller bearings 44, 46 are moved in the slits 40, 42 by a step motor 50 for controlling the valve timing. Signals relating to the pressure in an intake pipe, the water temperature, the engine speed, etc. are applied to a control circuit, which controls the valve timing to render the actually measured valve timing equal to an aimed valve timing stored in its memory. When the deviation between the actual value and the aimed value becomes zero, hold signals are supplied to the step motor 50 at prescribed intervals for fixing the motor, whereby it is enabled to prevent deviation of the valve timing even if turning force is applied from a cam. |
