| 摘要 |
PROBLEM TO BE SOLVED: To provide a drilling implement which can be easily pulled out in the state of placing a clod on a spiral blade, by pressing and compressing the clod placed on the spiral blade, even if the drilling implement is used for relatively-low-viscosity soil such as decomposed granite soil. SOLUTION: This drilling implement 10, in which a spiral body 20 is wound around the lower outer periphery of the base shaft 11, performs drilling work by being pulled up after being rotatively inserted into the ground while rotating the base shaft 11. A push-in plate 40 almost equal in diameter to a drilled hole HL is provided in the upper portion, in the direction of the base shaft 11, of the spiral body 20. When drilling implement 10 is rotatively inserted into the ground, the discharge of soil discharged by the spiral body 20 is regulated by the push-in plate. Thus, the discharged soil is pressed and compressed by the upper portion of the spiral body, and the clod placed on the spiral body 20 is tightened even in the case of the relatively-low-viscosity soil. This enables the drilling implement 10 to be easily pulled out in the state of placing the clod on the spiral body. COPYRIGHT: (C)2008,JPO&INPIT
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