| 摘要 |
<p>PURPOSE: To keep the required flowrate identical at all times, regardless of a cylinder driving direction, and prevent an excess increase in flowrate, regarding the driving hydraulic circuit of a telescopic mechanism for a hydraulically operated crane to move a heavy article such as a robot in a horizontal direction. CONSTITUTION: Regarding a telescopic type crane having movable arms 2 and 3 both axially slidable relative to a fixed arm 1 and telescopically movable, cylinders 4 and 5 to drive each of the arms 2 and 3 are arranged at opposite positions, so as to keep the rod sides thereof faced to each other. Then, the rod 6 of the cylinder 4 and the rod 7 of the cylinder 5 are connected to each other via a connection plate. Also, selector valves are directly connected to the large effective area bottom side chambers of the cylinders 4 and 5. On the other hand, the rod side chambers of small effective area are jointed to each. other through a single connecting valve. According to this constitution the cylinders 4 and 5 can be connected in series, or driven independently via the positional selection of the connecting valve.</p> |
