| 摘要 |
PURPOSE:To reduce the number of actions in maneuvering by offset moving a bucket automatically into the setting position in the position where turning of an arm support lever or a boom control lever to the work side causes the arm or boom angle to exceed a certain specified angle. CONSTITUTION:When a protrusion position auto-return switch 50 is turned on with start of excavating operation, the set rotational angle of an offset arm 22 is stored, and the revolving angle of a revolving table 12 is stored. Then soil and sand are scooped by a bucket 1, which is once accommodated at the side of a cabin 2, and after exhaust of the soil and sand, the revolving table 12 is returned to the original excavating position in this condition the bucket is accommodated. Then an arm control lever 9a or a boom control lever is fully turned, and an offset solenoid proportional valve 39 is actuated unless the arm 4 is in the prohibited zone, and an offset cylinder 3 will contract till the position of the setting rotational angle for the arm 22. When further the bucket 1 reaches the rotational angle setting position, the proportional valve 39 is deactuated, and a revolving solenoid proportional valve 51 is turned off. |
