| 摘要 |
<p>PURPOSE:To avoid high oil pressure from being exerted on a hydraulic tappet by providing an oil path for connecting between an oil pressure supply passage and the hydraulic tappet and providing a switching pin adapted to throttle the oil path as crossing the oil path and moving to the connection side. CONSTITUTION:During low-speed operation of an engine, switching pins 23-25 are in the state of disconnection, and circular grooves 40, 45 and circular recess portions 41, 46 are positioned corresponding to each other, so that low oil pressure from an oil pressure supply path 31 is not throttled, and supplied to each hydraulic tappet through respective oil paths 42, 43, 47, 48. On the other hand, during high-speed operation of the engine, high oil pressure is supplied to an oil pressure chamber 29, so that the respective switching pins 23-25 are moved against a return spring 26 and the first and second switching pins 23, 24 engage with the second and third guide grooves 33, 34, respectively to connect rocker arms 7-9 to one another. At this time, the first and third switching pins 23, 25 are moved to throttle between oil paths 42, 43 and between oil paths 47, 48.</p> |
