| 摘要 |
The present invention relates to a ground drilling machine for a large diameter when punching 500 mm or more of large diameter in the ground. The ground drilling machine for a large diameter sectionally extends an unit member by installing a Kelly bar drive to be elevated along a support. The ground drilling machine for a large diameter can drive the Kelly bar whose upper end is connected with a crane to be elevated at positive and reverse direction, and an excavating device capable of storing sand is connected to the lower end of the Kelly bar. The excavating device installs an auger screw under the Kelly bar, and a screw cap with open bottom is connected to the outside of the auger screw. The screw cap is detachable along a rotating direction of a drive of the Kelly bar. |
