| 摘要 |
PROBLEM TO BE SOLVED: To reduce machine length for execution of work of excavating a sharp curved line and stably hold a shield coaxially at the time of moving straight forward by connecting a front barrel and a rear barrel to each other with many bent-type jacks and loosely coupling a floating barrel to a connecting part. SOLUTION: A front barrel 2 with a cutter and a rear barrel 3 with a propulsive jack are arranged at intervals, and sealing extension parts 10 and 11 are connected to each other with many bent-type jacks 8 via a universal joint 9. A floating barrel 4 is loosely coupled to the external surface of a connecting part and space between the sealing extension parts 10 and 11 is sealed with bent-type seals 12 and 13. Also, a bearing seat 14 is projected inward from the lengthwise center of the floating barrel 4. When a bent-type shield 1 is moved straight forward, the ends of the sealing extension parts 10 and 11 are held on the bearing seat 14 and the front barrel 2 and the rear barrel 3 are stably held coaxially with dislocating the front barrel 2 and the rear barrel 3 in a breadthwise or a height direction. For excavation along a curved line, the bent-type jacks 8 at an outer position are expanded more than others, thereby making the shield 1 bendable like a sharp curved line about the bearing seat 14 as a bending center. |
