| 摘要 |
PURPOSE:To correctly control a device by mating two pairs facing each other of four gripper pads arranged on the circumference of a device main body, stretching them in turn, and fixing the front or rear gripper device to the wall face of the natural ground. CONSTITUTION:A frame 1 is divided into a front barrel 2 and a rear barrel 3, a front gripper device 11 is provided on the front barrel 2, and a rear gripper device 12 is provided on the rear barrel 3. When the excavation is completed by one stroke of an advance jack 4, the front gripper device 11 is stretched to the natural ground to hold the front barrel 2, then the rear gripper device 12 is shrunk, and the advance jack 4 is shrunk to pull the rear barrel 3 forward. The rear gripper device 12 is stretched to the natural ground to hold the rear barrel 3, then the front gripper device 11 is shrunk, and the next excavation is started. Gripper pads 14 are provided at four positions on the circumference of a ring-like device main body, they are extended or shrunk by gripper jacks 15, and signals of four pressure sensors 19 and stroke sensors 16 are inputted to a control device to control a selector valve 18. |
