| 摘要 |
PURPOSE:To increase the speed of executing works by performing the direction control of a cuter head easily and accurately using a simple structure, and performing simultaneously excavating forward, segment installation, and pulling nearer the rear trunk part. CONSTITUTION:Starting with the condition that all shield jacks 5 are elongated and a parallel link mechanism 6 is shrunk, the link mechanism 6 is elongated to allow a cutter head 3 to perform excavating forward, and at the same time, some jacks are shrunk one by one to perform installation of the corresponding segments 4 one after another. After completion of the excavating work by the cutter head 3 corresponding to the specified segment portion and laying of the corresponding segments 4, elongation of the shield jacks 5 and shrinkage of the parallel link mechanism 6 are conducted simultaneously while the position and attitude of the cuter head 3 remain as they are, and thereby the rear trunk part 2 is pulled nearer the front trunk part 1. |
