Electrohydraulic dynamic braking system and control method

摘要

The system has a control circuit (40) receiving braking request signals (SFR) from a servo-brake (20) and from an electronic stability program control module (30) to control a solenoid valve (70) of a high pressure accumulator (60) according to braking mode. The circuit controls a braking preparatory phase by assuring filling of the accumulator from a primary chamber (122) by actuating the servo-brake in absence of action on the brake or mechanical braking control and by blocking brake fluid load accumulated in the accumulator. The circuit controls dynamic braking phase decomposed into steps. One of the steps is a dynamic braking step with recuperation of energy by isolating a tandem master-cylinder (10) from wheel brakes (FR1-4) and by allowing the servo-brake to respond to action on the brake pedals until deceleration of threshold speed. Another step i.e. dynamic braking step, is realized from the threshold speed until a stop by connecting the primary chamber only to the accumulator and the module to provide the pressurized brake fluid of the accumulator to the module and to supply the wheel brakes for mechanical braking. An independent claim is also included for a braking method for an electrohydraulic dynamic braking system.