| 摘要 |
PURPOSE:To keep off the worsening of fuel consumption due to a sudden increment of engine speed by controlling the extent of line pressure electrically, and performing such control as making this line pressure higher than an ordinary controlled variable in the case where speed is shifted to the top direction. CONSTITUTION:A step motor 10 moves a shift control valve 13 via an actuator 11 and a valve stem 12 and puts high pressure oil into the side of a movable side pulley half body 20 of an input side pulley 18 of a continuously variable transmission 3, thereby reducing a transmission gear ratio being shown in the ratio between revolution of the input side pulley 18 and that of an output side pulley 19. In addition, oil out of the pulley half body 20 of the input side pulley 18 is put back to a reservoir 16 whereby a transmission gear ratio is enlarged. At time of line pressure control, first of all, whether it is in shift to the top side at present or not is judged. If it is a state of being shifted to the top side, a command is given to a pressure control valve 14 so as to maximize the extent of line pressure. At the time of being down-shift or constant in the transmission gear ratio, however, it comes to control over the ordinary line pressure. With this constitution, the worsening of fuel consumption is thus preventable. |
