| 摘要 |
<p>PURPOSE:To increase the reliability of the switching of the operation of a changeover valve by a method wherein in a device for changing the valve timing by moving rocker arms along a cam shaft, the rocker arms are moved by a high pressure oil stored in an accumulator. CONSTITUTION:The pressure oil from an oil pump 20 is stored in the accumulator 21 and the stored oil is supplied selectively to an operating pressure chamber 19A or 19B for driving the rocker arms 3 and 12 through an electromagnetic direction switching valve 22. The pressure in the accumulator 21 is detected by a pressure detecting means 25 and when the detected pressure is sufficiently high, the electromagnetic direction switching valve 21 is switched according to the operation condition of the engine. Accordingly, a drive power capable of moving the rocker arms 3 and 12 quickly is obtained and the reliability and durability of the valve are secured.</p> |
