| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To supply the hydraulic oil by only the necessary quantity set in an optional device, even when the optical device of different working pressure is mounted on a work device to perform the combined work. <P>SOLUTION: This hydraulic circuit comprising the work device mounted between a variable capacity-hydraulic pump 2 connected with an engine 1 and the optional device 4, and the optional device, further comprises a first spool 14 mounted on a flow channel between a poppet valve 13 mounted on a supply-side flow channel of a spool for the optional device in a state of being opened and closed, and the spool for the optional device, and having an opening part for keeping the specific pressure difference in switching, and a second spool 15 mounted on a downstream side of the poppet valve, and switched to close the poppet valve, when the overload of more than the pressure set in the optional device is generated. <P>COPYRIGHT: (C)2005,JPO&NCIPI</p> |
