OPERATION METHOD AND DEVICE OF INITIAL PUSHING DEVICE

摘要

PROBLEM TO BE SOLVED: To provide an operation method and a device of an initial pushing device wherein a push-in operation of an insertion pipe by the initial pushing device is automatically performed. SOLUTION: Agreement of a position of a front recess section 34a or a rear recess section 34b with an engagement pin 42 is detected by detecting an expansion moving position of a cylinder tube 33 and a moving position of a pushing plate 40. Both functions for making the cylinder tube 33 expand and contract by the same stroke as a distance between the front recess section 34a and the rear recess section 34b, and for inserting the engagement pin 42 into the front recess section 34a or the rear recess section 34b in an insertable manner, are controlled by a program. The insertion pipe supported by a positioning device is automatically thrusted into the ground by replacement movement of the pushing plate 40. COPYRIGHT: (C)2004,JPO