| 摘要 |
PURPOSE:To prevent delayed function of steering wheel by providing a pair of compensating pressure chambers while partitioning from reaction chambers at the opposite sides of spool of control valve for exchanging the flow of operating oil to a power cylinder. CONSTITUTION:A control valve 13 having reaction chambers 38, 39 is provided at the opposite sides of spool 29 in the hydraulic circuit for a power cylinder 14. A pair of compensating pressure chambers 42, 43 to be partitioned from the reaction chambers are defined by fitting spool guides 36, 37 in bores 34, 35 at the opposite sides of spool 29. While a restrictor 44 is placed in the hydraulic pressure feeding path 76 to lead the upstream pressure through compensating pressure control paths 45-47 into each compensating pressure chamber 42, 43. A compensating pressure control valve 48 is placed in said control paths 45-47 to be controlled by an actuator 55 through a control unit 56 on the basis of the outputs from a steering amount sensor 68 and a cylinder inner pressure sensor 69. |
