| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a construction equipment pressure control device for actualizing smooth drive of a working device having high load pressure in a hydraulic circuit where a plurality of control valves are connected in parallel to one hydraulic pump. <P>SOLUTION: The construction equipment pressure control device comprises a valve element 5 having an input port 1, an output port 2 and a drain port 3, a spool 13 using pressure supplied from the input port 1 to the pressure receiving part of a first piston 7 which is elastically supported in a first pressure chamber 6 slidably in the valve element 5 and the elastic force of a valve spring 9 for communicating the input port with the output port 2, and using pressure supplied from the output port 2 to the pressure receiving part of a second piston 11 which is provided in a second pressure chamber 10 for cutting off the input port 1 from the output port 2, and a signal pressure port 4 for supplying signal pressure to the pressure receiving part of the spool 13 in a third pressure chamber 14. With the change-over of the spool 13 to correspond to the signal pressure flowing into the third pressure chamber 14, operating pressure is controlled to be supplied from the input port 1 to the output port 2. <P>COPYRIGHT: (C)2008,JPO&INPIT</p> |
