| 摘要 |
PROBLEM TO BE SOLVED: To simplify the mechanism of a drilling device at drilling an elliptical tunnel, reduce the manufacturing cost, and simplify the construction control by providing a cutter slanting the cutter face on the end part of the skin plate of a shield machine. SOLUTION: In a skin plate 1 to be the outer shell of a shield machine, the section being at right angles to the axis of the shield machine is formed into an ellipse having a fixed flateness, and the hood opening 11 on the extreme end of a hood part is formed obliquely at a fixed angle. A circular cutter 2 conformed to the hood opening 11 is obliquely arranged on the hood opening 11, so that the shape in a view from the front in the advancing direction is made to be an ellipse, and when the shield machine is advanced in the axial direction by a shield jack while rotating the circular cutter 2 for drilling, an elliptical tunnel having the sectional shape of the skin plate 1 can be constructed. Because the elliptical tunnel can be drilled by the use of the circular cutter 2, the mechanism of the drilling device of the shield machine is simplified, and the manufacturing cost can be reduced. In addition, generation of eccentricity is reduced, and the construction control is simplified. |
