| 摘要 |
PROBLEM TO BE SOLVED: To provide a speed increase valve device properly switching a speed increase circuit according to presence or absence of a load borne by a double-acting hydraulic cylinder.SOLUTION: A speed increase valve device includes a controller 3 for determining magnitude of a load borne by a double-acting hydraulic cylinder 10, and a speed increase valve 20 for switching a speed increase circuit on the basis of a control signal from the controller 3. The controller 3 transmits a control signal for speed mode to the speed increase valve 20 when the magnitude of the load is determined to be a prescribed load or less, and transmits a control signal for ordinary mode to the speed increase valve 20 when the load is determined to be the prescribed load or more, and the speed increase valve 20 expands a rod 13 at an increased speed by opening the speed increase circuit 20k when the control signal is for the speed mode, and expands the rod 13 at a normal speed by blocking the speed increase circuit 20k when the control signal is for the ordinary mode.SELECTED DRAWING: Figure 1 |
