| 摘要 |
PURPOSE:To correct the direction of a guide pipe, by providing an extensible direction-correcting member by means of a hydraulic cylinder at the outer periphery of the front end of the guide pipe and receiving the earth pressure, protruding the correction member from the outer periphery of the guide pipe when the guide pipe is deviated from a projected line. CONSTITUTION:A direction-correcting device 7 is composed of a fan-shaped direct-correction member 7a pivoting the front edge at a guide pipe 1 by a pin 8 and a hydraulic cylinder 9 rotating arround the pin 8. A direction- correcting face 7b of the direction-correcting 7a is inserted into the inner side of the guide pipe 1 from a slit 1b to become the same plane with the outer peripheral face 1 on moving straight. And the direction-correcting member 7a is projected outward from the guide pipe 1 by the hydraulic cylinder 9 in the case of correcting the direction to receive the earth pressure on the direction-correction face 7b. And further, when the progressing direction of the guide pipe 1 is deviated from a projected line 10, the direction-correcting member 7a is rotated by the hydraulic cylinder 9 to project it from the outer peripheral face of the guide pipe to actuate the earth pressure on the direction- correting face 7b and to correct the front end for the projected direction. |
