| 摘要 |
PURPOSE:To enable more precious multistage control of valve timing, by a method wherein a sensor, which performs actual measurement of one reference value of valve timing, is mounted, and valve timing based on software is corrected each time the sensor is turned ON. CONSTITUTION:When a step motor 50, acting as a driving member for varying valve timing, is run, a nut 52, screwed on a rotary shaft 50' fabricated with an external thread, is moved in a direction A or B, roller bearings 44 and 46, located on a moving body 48 and formed integrally with the nut 52, are moved in the same direction within slits 40 and 42 which intersect each other. This causes outer and inner sleeves 36 and 38 to be relatively rotated, and the phase of a cam shaft 18 to a timing sleeve 28 is varied. In which case, a valve timing based on software is corrected each time a limit switch 90 for actually measuring one reference value of valve timing is turned ON, and according to such corrected timing, a step motor 50 is controlled. |
