Abstract: A control system (a control valve CV and an electronic control unit ECU) for an automatic transmission TM performs an automatic control to select and establish a speed ratio from a plurality of speed ratios in response to the condition of a vehicle which is set in a drive range. This control system creates a neutral condition if the vehicle is stationary with the brake of the vehicle being actuated and the accelerator for the engine being turned off while the transmission is set in a drive range. The control system is also equipped with an engine output control device 50 that adjusts the engine output which is input into the transmission when the transmission in the drive range leaves the neutral condition and starts to establish any of the speed ratios in the drive range.

Abstract: A torque converter in which a flatness (2L/H) and a torus inside and outside radius ratio (r/R) satisfy the following equations: (1) 0.55<(2L/H)<0.75 and (2) 35<(r/R)<0.40. Then, assuming that an axially central position of the flow path along a rotational shaft of the torque converter is an origin, an axial direction is an X direction and a radial direction is a Y direction, the configuration of the flow path of the turbine member is set such that the position of a point of contact between a straight line inclined 45 degrees relative to the X direction and a curve constituting an external circumference surface of the flow path in the turbine member is located within an area surrounded by two straight lines expressed as (3) Y=(R/L)×X+(6/4)×R and (4) Y=(R/L)×X+(7/4)×R.

Abstract: A control system (a control valve CV and an electronic control unit ECU) for an automatic transmission TM performs an automatic control to select and establish a speed ratio from a plurality of speed ratios in response to the condition of a vehicle which is set in a drive range. This control system creates a neutral condition if the vehicle is stationary with the brake of the vehicle being actuated and the accelerator for the engine being turned off while the transmission is set in a drive range. The control system is also equipped with an engine output control device 50 that adjusts the engine output which is input into the transmission when the transmission in the drive range leaves the neutral condition and starts to establish any of the speed ratios in the drive range.