| 摘要 |
<p>PURPOSE:To make sure of swiveling operation irrespective of arm load at the time of simultaneous operation with swiveling arm, while making it possible to perform digging, pressing bucket to the surface of wall, by putting swiveling force at the maximum produced by relief valve. CONSTITUTION:Oil hydraulic pumps 100 and 99 are connected with multiple valves 50 and 60 which send the oil discharged by the former to actuator. Arm selector valve 51 connected with arm cylinder 7, bucket selector valve 52 connected with bucket cylinder 6, boom selector valve 53 connected with boom cylinder 6 and traveling selector valve 54 connected with traveling motor 31 all are connected in parallel through line c linking to pump 100. Other valves 61-63 are connected in parallel through line d linking to pump 99. Line e on the unload side of pressure- reducing-type preferential valve 27 is connected with valve 51, and bent-type unload valves 15, 25 as well as bent-type relief valves 16, 26 having the same level of setting pressure as the pressure-loss of multiple valves 50 and 60 are built in these valves.</p> |
