| 摘要 |
PROBLEM TO BE SOLVED: To accurately control the position of a shield main body by controlling the stroke of a jack. SOLUTION: This shield machine S has a front shell 1a and a rear shell 1b formed by splitting a shield frame into front and rear parts along the direction of its axis, a holding jack 3 holding the position of the rear shell 1b by taking reaction from an existing segment 2 is provided around the rear shell 1b, and a propelling jack 4 propelling the front shell 1a relative to the rear shell 1b is provided between the front and rear shells 1a, 1b. In this case, the propelling jack 4 and the holding jack 3 are provided with respective stroke sensors 35, and control means 38 for controlling the amounts of strokes of the jacks 3, 4 are connected to the stroke sensors 35. |
