An engine brake control device for an automatic transmission.

摘要

A hydraulic pressure which is regulated by a pressure control valve (linear solenoid valve) is applied to a hydraulic servo of a brake which is actuated when an engine-brake is actuated. When the engine-brake is actuated, a regulated hydraulic pressure which is applied through a modulator valve controlled by the linear solenoid valve is applied to the brake hydraulic servo. At this moment, the pressure control valve provides high hydraulic pressure when vehicle speed is high based on signals from a speed sensor, while, provides low hydraulic pressure when vehicle speed is low based on signals from the speed sensor, so that an engine-brake force is adequately controlled in accordance with vehicle speed. Furthermore, in the case that signals from a foot brake sensor is added, the hydraulic pressure in accordance with vehicle speed is set to be low when the engine-brake is actuated. Based on a front wheel rotation sensor and a rear wheel rotation sensor, the control unit calculates rotational difference, thus the engine-brake force is controlled to be low when the rotational difference is large.