| 摘要 |
PURPOSE:To shorten length while executing a curved tunnel having a small curvature by forming a front partition wall and a rotary cutter to a conical shape, an outer circumference of which is inclined to the rear in the direction of excavation and which has an approximately parallel surface. CONSTITUTION:A front partition wall 16 and a cutter 13 rotatably supported to the partition wall 16 are formed to a conical shape, an outer circumference of which is inclined to the rear in the direction of excavation. The cutter 13 and the partition wall 16 are installed at approximately the same inclination to a shaft. The cutter 13 is turned and driven through gears 18 by a motor 17 while a cutter 20 housed at the outer circumferential end of the cutter 13 is projected and an outbreak is conducted, and a jack 7 for bending is operated and the cutter is curvedly propelled. Accordingly, length can be shortened only by S, the quantity of the outbreak is reduced, and a curve having a small curvature can be executed. |
