| 摘要 |
PURPOSE:To simplify the construction of a plunger pump for opening and closing an intake and exhaust valve with a hydraulically driven piston, by controlling the closing timing of a solenoid valve provided on the piston side. CONSTITUTION:A piston 14 is driven by oil pressure supplied from a plunger pump through a hydraulic conduit 43 to open and close an intake and exhaust valve 12. The plunger pump is controlled by a cam to control the opening timing of the valve. Oil paths 45, 46 are connected to a cylinder 41 and a solenoid 18 is interposed in these paths. Thus, by opening the solenoid valve 18 on the way of lifting the valve 12 escapes oil pressure in the cylinder 41 to close the valve 12 and control the closing timing of the valve 12 by the solenoid valve 18. Also the construction of the plunger can be simplified to reduce cost. |
