| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a fish tail mounted on a cutter head of a tunnel excavator, which excellently functions even in a long distance excavation condition, to thereby contribute to improved workability of the excavator. <P>SOLUTION: In a tunnel excavator, a main fish tail 30 is arranged at the center of a cutter head 11 which is mounted to be drivable and rotatable on the front of an excavator body 10, and soil excavated with the main fish tail is introduced via both side ends 30a of the main fish tail, and taken from cutter head openings O into a chamber 17 defined on a rear side of the cutter head. The tunnel excavator has a fish tail protective bit 32 arranged on the cutter head at a location which is radially the same location as that of both the side ends of the main fish tail, and thus the fish tail protective bit is retractable against the cutter head in an excavating direction, to allow exchange of cutter bits. <P>COPYRIGHT: (C)2012,JPO&INPIT |
