| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a hydraulic four-wheel-drive working vehicle in which at least one of a first and a second hydraulic motor units that drives one or the other first and second wheels in front-rear direction is a volume-changeable type, and its volume adjusting mechanism is activated by an electric motor based on a manual operation or the difference in turning radiuses of the first and the second wheels, while securing a running torque at the start of a vehicle without requiring an operation by an operator. <P>SOLUTION: A control device for controlling the operation of the electric motor has a normal mode which activates the electric motor in accordance with the manual operation or the difference in turning radiuses, and a torque-up mode which fixes the volume of a changeable volume side hydraulic motor to a first volume larger than a standard volume. The torque-up mode is activated when a driving source is in operation and a pump side volume adjusting mechanism is in a neutral state or a vehicle idling state, and the normal mode is activated when the vehicle speed reaches a first speed. <P>COPYRIGHT: (C)2012,JPO&INPIT |
