In the power-shift transmission the hydraulic clutch control unit

摘要

PURPOSE:To eliminate rapid engine brake action due to deceleration so as to reduce a speed change shock by providing a hydraulic clutch boost delay means for controlling a hydraulic clutch so as to increase a time before it is connected when a speed change is shifted to a low speed side. CONSTITUTION:When a power shift transmission is shift-operated by an opera tor, a hydraulic clutch 11, to be connected with that time, is cut off, while a shift detecting means 5b detects whether a speed change is shifted to a high speed side or a low speed side. When the speed change is judged to be shifted to the low speed side, the hydraulic clutch is controlled by a hydraulic clutch boost delay means 5a in such a way that a time until the concerned hydraulic clutch 11 is connected to a newly shifted position is increased longer as com pared with that for shift operation to the high speed side. Thus, by delaying connection of the concerned hydraulic clutch 11 to the newly shifted position, the hydraulic clutch 11 is connected so as to prevent engine brake action from being applied.