| 摘要 |
PROBLEM TO BE SOLVED: To reduce the mechanical load of excavating edges and an outer ring by fitting a plurality of cutter bits to the front face of a spoke protrusively forwardly than the excavating edges and outwardly than the outer ring. SOLUTION: Many excavating edges 6 are fixed on both sides of the spoke 3 of the cutter disk of a shield machine, and they are rotated for an excavation. A plurality of cutter bits 10 are fitted to the front face of the spoke 3 protrusively forwardly than the excavating edges 6 by the size B, and the cutter bits 10 on the outermost periphery are protruded outwardly than the outer ring 5 by the size A. Circular holes are formed on a base material 11 made of carbon steel for a mechanical structure, cylindrical cemented carbide tips made of a cemented carbide alloy are inserted, buried, brazed, fixed, and planted in zigzag in three lines and seven rows with semispherical tip sections exposed to form the cutter bit 10. Mechanical loads applied to the outer ring 5 and the excavating edges 6 are sharply reduced, and excavation performance can be stably maintained over a long period. |
