| 摘要 |
<p>PURPOSE:To enable to perform other control as straight running is held, by a method wherein the running control valve of the control valve group of a first hydraulic pump is communicated, downstream from the bucket control valve of a second hydraulic pump, with the oil pressure of the second hydraulic pump through a separate bypass line. CONSTITUTION:In a 2-pump hydraulic system, a boom control valve 14B and an arm control valve 11A are connected in parallel to a first hydraulic pump 1, and a running control valve 10 is connected in series downstream from an arm control valve 11A. Meanwhile, a bucket control valve 13 is connected, in series to a running control valve 12, to a second hydraulic pump 2. Bypass lines 44 and 47, through which the second hydraulic pump 2, a bucket control valve 13, and the upper stream of the running control valve 10 are intercommunicated, are installed. This enables other actuator to perform independent control as straight running ability is maintained.</p> |
