PURPOSE: To let both the enhancement of engaging responsiveness for frictional engaging elements and the prevention of engaging shock be concurrently satisfied.
CONSTITUTION: An accumulator ACC is connected to a working pressure feed line 63 for a low reverse brake 44 which is engaged when a neutral range is changed over to a reverse range. The pressure of the back pressure chamber 84 of the accumulator ACC is separately set up independently from line pressure. The pressure of the back pressure chamber 84 can be made zero or constant in low pressure, or can be controlled to be variable by a control valve 73. When a change-over to a reverse range is made, line pressure can be made high (pre-charge) almost close to its highest pressure before turbine revolution starts lowering (before the low reverse brake 44 starts engaging).
MATSUMOTO AKIO
DOI JUNICHI
MARUSUE TOSHIHISA
