| 摘要 |
<p>PURPOSE:To prevent a vehicle from abruptly starting upon releasing of an operating brake by operating the brake of a motor when a malfunction occurs in the state that a speed instruction unit is set to travelling position, holding this state and releasing the holding of the operation when the instruction unit is set to a stop position. CONSTITUTION:When an operating lever is removed from a stop position and is inclined, the output of a stop detector D becomes ''L'', and the transistor Tr2 of a brake control circuit E becomes ON. Accordingly, the speeds of a right motor MR and a left motor ML are controlled by the oblique angle of the lever. When the output of a malfunction detector G becomes ''L'' in this state, the output of a holding circuit H becomes zero, thereby causing the transistor Tr2 to be turned OFF, and applying a brake. When the lever is returned to the stop position after the malfunction state is eliminated, the output of the stop detector D becomes ''H'', thereby causing the output of the holding circuit H to become ''H''.</p> |
