| 摘要 |
PROBLEM TO BE SOLVED: To provide an underground boring machine capable of injecting concrete or the like into a bored hole and discharging generated slime to the outside by flowing back through a water injection pipe in a state of not removing a screw shaft and a down hammer after boring the ground. SOLUTION: A hammer body 105 at the lower end of the down hammer 104 constituting the underground boring machine is provided with a water hole 106 extending from the bottom face center to the upper end, and a plurality of air holes 107 radially extending from the water hole 106 and connected to the water hole 106 in a fixed height position from the bottom face of the hammer body 105. The water injection pipe 108 is installed from a supply body 102 into a position below an intersecting point of the hammer body 105 so that water or the like supplied to the supply body 102 passes through the intersecting point of the water hole 106 and air holes 107 and is discharged only from the water hole 106. Compressed air supplied to the supply body 102 flows along the outer side face of the water injection pipe 108 and is discharged from the air holes 107. COPYRIGHT: (C)2008,JPO&INPIT
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