| 摘要 |
<p>PURPOSE:To improve fuel consumption by always making it possible to set optimum valve opening time of a suction/exhaust valve irrespective of an engine turning speed while improving a hydraulic tappet structure in a device where the suction/exhaust valve is closed and opened via the operation of the hydraulic tappet sliding on a cam. CONSTITUTION:Discharged oil from a pump is forcedly sent via communication holes 12, 18, 25 to a hydraulic tappet 8 opening and closing a suction/exhaust valve via a push rod 5 and a locker arm while being subjected to elevation force produced by a cam interlocking with engine rotation and supplied to the second and first space parts 23, 20 by opening and closing a check valve 30. In this situation, a body 10 is slowly lifted resisting the first and second springs 21, 29 by means of a cam, for example, during engine running with a low speed, so that much amount of the oil in respective space parts 20, 23 is discharged from an exhaust outlet 13. Accordingly, both a gap A for valve clearance and a gap B for lift loss become zero, followed by the decreased lift amount of the suction/exhaust valve, allowing valve opening time to be shortened.</p> |
