| 摘要 |
PROBLEM TO BE SOLVED: To prevent either the front or rear wheels of a coupled vehicle body from being separated, against magnetic attracting forces, from the part of the inner surface of a pipe which is curved in the thickness direction of the wall of the pipe. SOLUTION: Vehicle bodies 1, 2 each having wheels which are magnetically attracted to the inner surface B1 of a pipe are coupled together, and at least one of the vehicle bodies comprises a driving vehicle body. A coupling member 13 freely vertically swingably supported on the driving vehicle body and on the coupled vehicle body couples the driving vehicle body and the coupled vehicle body 2 together in such a way that the vehicle bodies are free to travel inside the pipe B. The coupling member is provided in such a way that the vehicle bodies travel on the part C of the inner surface of the pipe which is curved in the thickness direction of the wall of the pipe, a line L connecting the swing axis Y1 of the coupling member relative to the driving vehicle body with its swing axis Y2 relative to the coupled vehicle body and an extension thereof are held in the state of passing between the contact positions Pa, Pb of the front and rear wheels 4a, 4b of the coupled vehicle body with the part of the inner surface of the pipe on side view. |
