| 摘要 |
<p>PCT No. PCT/JP89/00496 Sec. 371 Date Mar. 14, 1990 Sec. 102(e) Date Mar. 14, 1990 PCT Filed May 16, 1989 PCT Pub. No. WO89/11411 PCT Pub. Date Nov. 30, 1989.A hydraulic circuit apparatus for use in construction vehicles which is arranged to reduce pressure losses that occur when all the implement operating valves are kept at their neutral positions, to reduce the power consumption by all hydraulic pumps when the hydraulic circuit for implements require only a small amount of pressurized fluid, and to transmit a command signal to unload the surplus pressurized fluid when occasion demands. The circuit comprises a surplus pressurized fluid control circuit (50) to facilitate the regulation of changes in the fluid flow rate when changing over valves. The surplus pressurized fluid control circuit (50) has a pilot actuated type unloading valve (11) provided in a surplus pressurized fluid supply conduit (51) which is connected through a check valve 20 to a hydraulic pump (P1). The hydraulic pump (P1) is for the exclusive use of the implement. The conduit (51) is also connected to a drain conduit (Ct). A pilot pressure change-over valve (12) is provided in a pilot conduit (19) for the unloading valve (11).</p> |
