| 摘要 |
PURPOSE: To enhance operability and excavating efficiency by arranging a sealed slidingly movable part between spoke intermediate cylinder and inner cylinder mutually slidingly moving with spoke inner and outer cylinders, and arranging whirl-stop guides and a bit housing part between the intermediate cylinder and the outer cylinder. CONSTITUTION: Spoke outer cylinder 1 and inner cylinder 2 having a large number of cutter bits 4b are fixed to a cutter head central member 6, and are connected to a spoke intermediate cylinder 3 having a large number of cutter bits 4a. In this case, the intermediate cylinder 3 is fitted to the inner cylinder 2, and is formed as a slidingly movable surface, and a sealing member 8 is fitted to and installed on the upper outer periphery of the inner cylinder 2. A whirl-stop guide 7 is installed on the outer periphery of the intermediate cylinder 3, and is fitted to a pair of whirl-stop guides 9 fixed to the outer cylinder 1. A clearance is arranged between the intermediate cylinder 3 and the outer cylinder 1, and when the intermediate cylinder 3 contracts, a cutter bit 4a provided on the intermediate cylinder 3 can be housed in the outer cylinder 1. An earth and sand entrance preventive plate 10 is installed in an outer peripheral part of the intermediate cylinder 3. Therefore, the intermediate cylinder 3 is extended and contracted through a hydraulic jack 5, and an excavating outside diameter is changed, and outbreak can be performed. |
