PURPOSE: To reduce the occurrence of disturbance during regulation of pressure for the grip change shift of a frictional engagement element and to control a release pressure without a replay delay.
CONSTITUTION: A shift is effected through grip change of a frictional engagement element, and an oil pressure control device for an automatic transmission comprises hydraulic servoes 29 and 28, a switching valve 22; a signal pressure generating means; and a pressure regulating valve 25 to regulate a feed pressure to the hydraulic servo 28. The pressure regulating valve 25 comprises a first valve body 253 to receive a signal pressure PSLU and the feedback pressure of the release pressure of the hydraulic servo 28; and a second valve body 252 to receive the engagement pressure of the hydraulic servo 29, and the second valve body 252 is always energized for contact with the first valve body by an energizing means 259.
ANDO MASAHIKO
FUKATSU AKIRA
SAKAI MOTOYUKI
KAIGAWA MASATO
FUKUMURA KAGENORI
OBA HIDEHIRO
HOJO YASUO
TABATA ATSUSHI
TAKAHASHI NOBUAKI
TOYOTA MOTOR CORP
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