| 摘要 |
PURPOSE:To switch a large flow with high responsiveness by connecting pressure chambers on both sides of a control land of a main spool directly from a pump port and through a throttle, and introducing pressure in one pressure chamber into a pilot pressure chamber between lands of a pilot spool to move the main spool, following the position of the pilot spool. CONSTITUTION:When an electric current is not applied to a proportional solenoid 14, a pilot spool 15 is pushed to the right by a bias spring 13, and when an electric current is applied thereto, it is pushed to the left according to the current strength. When pressure oil is applied to a main spool 6, pressure oil is introduced into the respective pressure chambers 25, 26, a control edge 31 between a land 16 of the spool 15 and the spool 6 is opened, pressure oil flows out to a tank port T to cause a pressure loss in a throttle 24, and the spool 6 is pushed to a position where a flow balanced by a spring 22 flows out of the edge 31 and positioned. Thus, suction force to the solenoid is changed to increase the passing flow of a control valve device so that the responsiveness can be improved. |
