| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a rod chuck holding circuit for a boring machine capable of positively preventing a lowering of holding force to a drill rod by preventing the drop of pressure in a hydraulic cylinder for driving a chuck mechanism. <P>SOLUTION: The rod chuck holding circuit 3 is provided with the hydraulic cylinder 4 for driving the chuck mechanism 2 for holding the drill rod 1; a holding pipeline 5 for putting the chuck mechanism 2 in the holding state by feeding pressure oil to one chamber 4a of the hydraulic cylinder 4; and a release pipeline 6 for putting the chuck mechanism 2 in a hold release state by feeding pressure oil to the other chamber 4b of the hydraulic cylinder 4. The pressure oil is supplied to the holding pipeline 5 through a first connecting pipeline 16 with a shuttle valve 15 and through a second connecting pipeline 17 with a check valve 18 from a motor driving circuit 10 for driving a hydraulic motor 11 for rotating the drill rod 1. <P>COPYRIGHT: (C)2004,JPO&NCIPI</p> |
