| 摘要 |
PURPOSE: To ensure a correct balanced condition by equipping a feed bar reciprocatively moving in a plane orthogonal to the center axial line, and a balancing means for reciprocatively moving a counterbalancing means synchronizing with the feed bar in a direction opposite to that of the feed bar. CONSTITUTION: When a feed bar 33 is at a position farmost in a diameter direction from the center axial line 31, the piston rod 101 of a fluid cylinder 83 extends fully, and the piston rod 103 of a fluid cylinder 85 is retracted fully. When a main shaft 49 moves forward in an axial direction to move a feed bar 33 toward the center axis line 31, the piston, rod 101 is pushed into the cylinder 83, thereby flowing fluid into the cylinder 85. The piston rod 103 is extruded to move a counterbalancing means 87 toward the axis line 31. The means 87 is positioned within the plane of rotation same as that of the feed bar 33, thereby minimizing the problem due to dynamic unbalance. |
