PURPOSE: To reduce shift shock by providing a cut-back pressure port for adjusting a line pressure in the pressure increasing direction, on a primary regulator valve and supporting a cut-back pressure from a cut-back valve.
CONSTITUTION: Since an oil pressure is not supplied on an oil pressure servo B2 for D range/first speed step, second speed step braking, a cut-back valve 59 is intercommunicated with input/output ports (q), (j1) so as to supply a pressure corresponding to an output from a valve 53 to a cut-back pressure port (j) of a primary regulator valve 52, thus enhancing the line pressure of the port (p2). In the second speed step or more, the cut-back valve 59 intercommunicates an output port (j1) with a drain port EX, so as to set the line pressure at the lower value. The primary regulator valve 52 sets the line pressure by supplying a pressure corresponding to the output to the port (j) so as to exert a feedback pressure to a lower control chamber (f). Thus, it is possible to reduce shift shock and simplify the structure of a valve corresponding to the engine output.
TSUKAMOTO KAZUMASA
TANIGUCHI TAKUJI
TOMOMATSU HIDEO
KONDO TEI
IWATSUKI KUNIHIRO
TOYOTA MOTOR CORP
| JPS6121456A | 1986-01-30 |