| 摘要 |
PURPOSE:To form a feed drill to compact construction, by integrally forming a mechanism, controlling forward and backward movements of a main shaft, with a drill main unit. CONSTITUTION:At operation of boring work or the like, compressed air fed from a forward feed pressure port 10 reaches the rear end face of a piston 5 and a hollowed part 9 through a feed pressure line 11 to press the piston 5 forward, then a motor case 2, rotor 6 and main shaft 8 are forwarded. Here oil or the like in space 15 passes a gap between a needle valve 18 and wall face 26 through a flow line 14, space 13 and communication hole 25 by the forwarding motion of the piston 5 to flow out from a backward feed pressure port 17. At an end of this boring work when the main shaft 8 is moved backward, a valve 12 is moved backward by feed pressure from the backward feed pressure port 17 against pressing force of a spring 19 and the like, and pressure is fed from the space 13 and flow line 14 to space 15 to press the piston 5 to the rearward. |
