| 摘要 |
PURPOSE:To improve operating property and safety by providing an electromagnetic selector valve which selectively shifts a pilot pipe line to a hydraulic pipe line for manual controlling and to a hydraulic pipe line for automatic controlling, on said pilot pipe line for shifting of a pilot type direction control valve. CONSTITUTION:The pilot pipe lines 22, 23 for shifting of a pilot type direction control valve 5, are selectively connected to hydraulic pipe lines 15, 16 for manual controlling and hydraulic pipe lines 27, 28 for automatic controlling via electromagnetic selector valves 20, 21 respectively, and a pressure switch 18 is connected to both the hydraulic pipe lines 16, 16 for manual controlling via a shuttle valve 17, and inputted into the controllers of the electromagnetic selector valves 20, 21. Thereby, even at the time of automatic controlling, if a manual operating lever 12 is operated, the electromagnetic selector valves 20, 21 are immediately shifted to manual control positions, thereby, enabling the correction of a course by means of manual operation at the time of possible danger, improving operating property and safety.
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