| 摘要 |
PURPOSE:To easily connect a direction-switching valve to be increaed in parallel by providing a by-pass line for branching pressurized oil supplied to a direction- switching valve in a concentrator and a pump port for increase which is adapted to externally connect the by-pass line to a direction-switching valve to be increased. CONSTITUTION:A concentrator 1 includes for example, three direction-switching valves 2-4, work ports of which are connected to actuators by output circuits A1-A3, B1-B3. Center by-passes 5a, 5b are branched into two, a common pump port 6 connected to the by-pass 5a being connected to a hydraulic pump 3, a common tank port 9 connected to the center by-pass 5b being connected to a tank 11. In this case, a by-pass line 21 is disposed in the apparatus 1, one end thereof being connected to the center by-pass 5a, the other end thereof being connected to a pump port 22 for increase. The port 22 is connected to a pump port P4 of a direction-switching valve 18. |
