Electro-hydraulic brake system with electric power assist and by-wire braking

摘要

An electro-hydraulic brake (EHB) system of a vehicle, the vehicle is equipped with brake pedal, brake pushrod, wheel cylinders, brake pedal sensors, on-board vehicle sensors. The EHB system includes a manual boost cylinder, an electric power assist assembly and a master cylinder. The manual boost cylinder includes a sliding cylinder body, a large piston and a small piston. The manual boost cylinder also include interlocking means that selectively operate on locking or unlocking between the sliding cylinder body, the small piston and the large piston based on a plurality of positions of the small piston within the manual boost cylinder body. The electric power assembly includes an electric motor, a pinion gear and a rack and a master cylinder. The master cylinder includes a first piston, a second piston and limiter means.

主权项

1. An electro-hydraulic brake system of a vehicle having brake pedal, brake pushrod actuated by the brake pedal, wheel cylinders, brake pedal sensors, on-board vehicle sensors, said electro-hydraulic brake system comprising:
a manual boost cylinder comprising a manual boost cylinder body, said manual boost cylinder body having an inner wall defining a first cylinder, a sliding cylinder body inside the first cylinder, said sliding cylinder body having a front inner wall defining a second cylinder and a rear inner wall defining a third cylinder, a large piston reciprocably movable inside the second cylinder, a small piston that is smaller in diameter than the large piston reciprocably movable inside the third cylinder, said sliding cylinder body, small piston and large piston reciprocably movable within the manual boost cylinder body, and an interlocking means that selectively operates on locking or unlocking between the sliding cylinder body, the small piston, the large piston and the manual boost cylinder body based on a plurality of positions of the small piston within the manual boost cylinder body; an electric power booster comprising a rack and an electric motor; a master cylinder comprising a first piston, a second piston, said first and second pistons reciprocably movable inside the master cylinder, and limiter means; a front pushrod connecting, and reciprocably movable between, the manual boost cylinder and the electric power booster; a push bar connecting, and reciprocably movable between, the electric power booster and the master cylinder; and an electronic control unit (ECU) electrically connected to the brake pedal sensor, on-board vehicle sensor and the electric motor.