| 摘要 |
PURPOSE:To reduce a turning operation force and to change the direction of the left and right front wheels quickly and lightly by actuating a steering handle to the turning side in accompany with the stoppage of the driving rotation of one of the left and right rear wheels on the turning side. CONSTITUTION:Individual steering brakes 29 of the left and right rear wheels 2 are operated by a pair of left and right brake operation pedals 30. The direction of the left and right rear wheels 1 is changed by a steering handle 7 through a pitman arm 34, drag link 35, and pivot case 32. And, a pair of springs 36a, 36b actuating the handle 7 to the left turning side and right turning side are provided so as to act on an arm 37 fixed to the pivot case 32. The actuating or non- actuating actions of the springs 36a, 36b are switched by a hydraulic cylinder 38, which is controlled by a control valve 39. The switching control of the control valve 39 is performed in accordance with the operation of the pedal 30 through an arm 40. |
