Automatic transmission control device

摘要

A control device for controlling an automatic transmission determines whether a fluid pressure of the operation fluid acting on a friction engagement element that is switched from a released-state to an engaged-state is in a fully-decreased state. If determined that the fluid pressure is not in a fully-decreased state, control of a manual valve is delayed. In such manner, the hydraulic circuit is switched by the manual valve after the full decrease of the fluid pressure of the operation fluid acting on the just-engaged friction engagement element. As a result, an abrupt rise of the fluid pressure is prevented and a shock in the automatic transmission is reduced.

主权项

1. A control device for an automatic transmission comprising:
a manual valve switching a hydraulic circuit to control a flow of an operation fluid acting on a friction engagement element disposed in a gearbox; a fluid-pressure control valve controlling a fluid pressure of the operation fluid acting on the friction engagement element; a controller switching a shift range to a target range according to an operation of a range selector by controlling the manual valve and the fluid-pressure control valve; a decreased fluid-pressure determiner determining whether the fluid pressure of the operation fluid acting on a just-engaged friction engagement element, which is switched from a released-state to an engaged-state according to a switching of the target range, is fully decreased; and a hydraulic circuit time delayer delaying a switching timing of the hydraulic circuit by the manual valve to a delayed timing when it is determined that the fluid pressure of the operation fluid that acts on the just-engaged friction engagement element is not in a fully-decreased state.