| 摘要 |
PURPOSE:To enable fine switching operations to be performed and also braking forces to be transmitted to four wheels exactly by a method in which an intermittent operation device permitting switching of two-wheel drive and four- wheel drive is provided, and when a running brake is operated, a switcher is always switched to four-wheel drive. CONSTITUTION:Front wheels 3 and rear wheels 4 are provided to a lowr runner 1 and a rotation source 81 is provided to the upper rotator 2. The rotation force of the rotation source 81 is transmitted through a fluid-pressure pump 82, a pipe 84, a rotary coupler 85, and a fluid-pressure motor 83 to a casing 86. Also, a transmission shaft 22 from the casing 86 to the front wheels 3 and a transmission shaft 23 to the rear wheels 4 are provided, and two-wheel drive and four-wheel drive are switched to each other by switching a switching valve 72. When a running brake 55 is operated, a spool 49 inside the casing 86 is pushed to switch the operation state to four-wheel dirve and the braking force is transmitted. By this, the brake can be exactly operated and also two-wheel drive and four-wheel drive can be optionally chosen. |
