| 摘要 |
PURPOSE:To display the drilling state of a free cross section shield machine with an inexpensive structure and on a real time basis. CONSTITUTION:A tunnel of cross section other than a circular form is excavated with a main cutter fixed to a cutting wheel, and a planetary cutter rotatably mounted thereon via a turning member driven with a hydraulic cylinder. Also, an orbit deviation operation section 62 computes an orbit deviation DELTAr from the stroke deviation DELTAC of the hydraulic cylinder, on the basis of a cutting wheel rotation angle detected with a cutting wheel rotation angle detector 38 during drive control and a conversion factor stored in such an orbit deviation conversion factor memory section 61 as corresponding to the rotation angle. The deviation DELTAr is used for an alarm with an alarm unit 66 or an indication with an indicator 67. |
