| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a multi-axle vehicle which can switch intermediate wheels to have an optimal steer angle according to various modes even when a cylinder diameter of an intermediate steering shaft is made to be the same as that of the cylinders of the other steering shafts without causing cavitation, boost pressure, operational failure or the like upon switchover of the steering modes. <P>SOLUTION: First, second and third intermediate part two-positional switching valves 4<SB>V1</SB>, 4<SB>V2</SB>, 4<SB>V3</SB>are provided in an intermediate part hydraulic circuit 4, which keeps a front part hydraulic circuit 2 and a rear part hydraulic circuit 3 communicating in series by the switchover of a front part switching valve 2<SB>V</SB>, to switch a first mode which makes the oil pressure act on a head side oil chamber and a rod side oil chamber of right and left side intermediate part cylinders 4a, 4b, a second mode which makes the oil pressure of the operating oil act only on the head side oil chamber, and a third mode which makes the oil pressure of the operating oil act only on the rod side oil chamber. An oil returning and replenishing line 5 is provided to settle excess and deficiency in the operating oil which is reversibly moved from the intermediate part cylinder to the other intermediate part cylinder. A bypass line 4f for bypassing part of the operating oil is provided. <P>COPYRIGHT: (C)2008,JPO&INPIT |
