| 摘要 |
The present invention relates to an apparatus for hole drilling using a PRD method used in the normal hole drilling in less than 1000Φcomprising: external casing included in a large sized hole drilling position in more than 2000Φ; internal casing included inside the external casing; first connection units included between the external casing and the internal casing by combining with the internal casing; a guide unit including space units formed between the external and the internal casing through the first connection unit; an air hammer which is rotated; a bit included under the air hammer; and a hole drilling unit for the PRD method including the casing included in the circumference of the air hammer. The hole drilling unit for the PRD method has the opposite direction with the rotation direction of the air hammers. The air hammer is connected to a hook and an end of a crane including a boom which is sloped by a main body with a predetermined angle. A space unit is formed as an insertion size related to the hole drilling unit for the PRD method. The hole drilling unit for the PRD method successively makes holes along with an inner partition of the external casing to effectively and rapidly execute a large hole drilling process. |
