| 摘要 |
PURPOSE:To improve response performance by providing a switching valve leading hydraulic oil in the high-pressure side cylinder chamber of a power cylinder to a differential pressure detecting means to integrally collect a differential pressure detecting means and the switching valve to reduce line resistance. CONSTITUTION:This device is provided with a hydraulic pump 3 driven by an electric motor, a sensor-closed type servo valve 5 operated by steering a steering device 91, and a power cylinder 94 operated according to the operation of the servo valve 5. Also switching valve 2 is provided by which oil pressure from the high-pressure side cylinder chamber 94A of a cylinder 94 is drawn to be led to a differential pressure detecting means 1 is provided. A spool 11 is moved by the differential pressure between oil pressure on a high-pressure cylinder chamber 94A side introduced from a switching valve 2 and line pressure from a supply path 51. Resultingly a displacement detecting means 12 is operated to output a signal to a controlling means to drive an electric motor. The switching valve 2 and the differential pressure detecting means 1 are housed in the same housing 19, and moreover the servo valve 5 is integrated to shorten an oil pressure passage. |
