| 摘要 |
PURPOSE:To make efficient use of features in both systems of a body fold type and a wheel steering type and thereby secure such a steering system that is extensive in application ranges and convenient for farm working by selectively setting an optimum steering state according to running conditions of a farm working vehicle. CONSTITUTION:When speed is more than 10km/h by detection of a sensor, a vehicle is kept in a front-wheel steering state automatically by a control circuit if a handwheel is operated, and a minimum turning radius in case of steering up a handwheel at this time comes to a value (r1) depending on about 30 deg. of a maximum steering angle of front wheels 1, 1 in the farm working vehicle. In addition, when it is within a range of car speed 10km/h-3km/h, it is kept up in an all-wheel steering state automatically by the control circuit if the handwheel is operated, whereby the minimum turning radius in case of steering up the handwheel at this time comes to a value r2 depending on what front wheels 1, 1 and rear wheels 5, 5 are steered at the maximum steering angle (about 30 deg.) simultaneously. |
