| 摘要 |
PURPOSE:To excavate a horizontal hole having a square cross section. CONSTITUTION:A rotary bulkhead 3 is rotatably supported on a support plate 2 fixed on the inside of a skin plate 1 having a square cross section. A rotary shaft 15 is rotatably coupled at the position eccentric to the center of the skin plate 1 of the rotary bulkhead 3. A cutter head 20 is fixed at one end of the tip of the rotary shaft 15, an external gear 31 is fixed at the other end, and the external gear 31 is meshed with an internal gear 32. A hood 16 having a conical opening face 16a is arranged on the inside of the skin plate 1 between the cutter head 20 and the rotary bulkhead 3. A cone 17 is rotatably supported at the portion of the rotary shaft 15 located on the inside of the hood 16. The rotary shaft 15 and the cutter head 20 are put into planetary motion by the rotation of the rotary bulkhead 3. The equilateral triangular excavation section of the cutter head 20 excavates a horizontal hole having a square cross section. |
