Hydraulische Steuerung für Automatikgetriebe.

摘要

A hydraulic control system for an automatic transmission has a shifting shock reducing device (112) capable of regulating the transitional oil pressure applied to the frictionally engaging devices (B2) of the automatic transmission, and provided between a shift valve (114) and the frictionally engaging devices (B2). The shifting shock reducing device (112) is controlled on the basis of a signal Pth representative of the torque of the engine, and a signal Psl representative of the transitional shift state to regulate the transistional oil pressure. Thus, the hydraulic control system is highly reliable, is capable of compensating for variations of the functions thereof over time, and is capable of maintaining a high control accuracy.