| 摘要 |
PURPOSE:To obtain the titled controlling device having an excellent responsibility by a method wherein a flow rate control valve installed between a rod contracting side chamber duct and a rod extruding side chamber duct of a boom cylinder is controlled by means of an operation system inputting a comparative position signal between an arm and a boom. CONSTITUTION:A switch 27 is turned ON and a boom 2 is optionally made to move upward or downward with an operation of a boom change-over valve 10. And the switch 27 is turned OFF and the valve 10 is placed in a neutral position and when an arm switching valve 9 is placed at an arm extruding position, the point of an arm 3 draws a locus A. Further, the switch 27 is turned ON, and the valve 10 is placed at the neutral position, and when the valve 9 is placed at an arm extruding position, an output of an operation system 26, namely, a control signal I enters a flow rate control a value 23, and an oil passing flow rate becomes a value corresponding to the signal I. And further, the oil in a rod extruding side chamber to a boom cylinder 5 flows with a flow rate corresponding to the signal I, and a part thereof flows in a rod contracting side chamber of the cylinder 5 and the residual flows into a tank 25. Accordingly, the cylinder 5 contracts with a speed corresponding to the signal I and the boom 2 moves downward with a speed corresponding to the signal I, thus, making the point of the arm 3 draw a required locus such as B-E. |
