Hydraulic control unit for automotive transmissions.

摘要

O A hydraulic control unit for an automotive transmission has a change gear operating mechanism and a clutch operating mechanism. All incorporated in the control unit housing in one body are the component parts of the former mechanism of a first hydraulic actuatorfor gear shifting and gear selection of the speed change gear, solenoid valve means for controlling said first hydraulic actuator, position sensors for sensing positions of the first hydraulic actuator indicative of the selected gear position and shifted gear position of the speed change gear, as well as of the latter mechanism of a second hydraulic actuatorfor engagement and disengagement of the clutch, solenoid valve means for controlling the second hydraulic actuator, and a position sensor for sensing the position of the second hydraulic actuator indicative of engagement and disengagement of the clutch. An air breather provided on the control unit housing on the side of the speed change gear communicates with an air chamber of the second hydraulic actuator through a passage formed within the control unit housing, to also serve as an air breather for the same chamber.