| 摘要 |
<p>PURPOSE:To prevent an electric motor vehicle from sliding down on a slope by detecting the operating sequence of a forward-reverse switching contactor to thereby discriminate the plugging state at the slope starting time and producing strong braking force for the vehicle. CONSTITUTION:When an electric motor vehicle starts moving up on a slope at forward travel and starts forwardly moving up from the middle on the slope, the same exciting coils of forward-reverse switching contactors SW1, SW2 are continuously energized. Accordingly, operating sequence detector RD produces no output resulting in no closure of a switching element S. When the vehicle body slides down on the slope it becomes in plugging state to cause a plugging control circuit H to tend to reduce instruction current Is. since the element S is, however, not closed, the instruction is not transmitted. That is, it becomes the state corresponding to larger instruction current transmitted than the ordinal plugging state resulting in no reduction of braking force. Accordingly, it effects stronger braking force applied to the vehicle.</p> |
