A Composite Brake System with Brake-by-Wire Function

Abstract

The invention discloses a compound braking system with a brake-by-wire function and belongs to the technical field of car braking. The compound braking system with the brake-by-wire function includesa brake pedal, a brake booster, a brake master cylinder, two-position five-way sliding valves, travel simulators, a hydraulic adjusting module (a motor, an oil pump, a high-pressure energy accumulator, two-position two-way electromagnetic valves and hydraulic adjusting cylinders), a pedal displacement sensor, pressure sensors and a brake controller. The compound braking system with the brake-by-wire function is characterized in that two independent hydraulic control mechanisms are integrated, the two-position five-way sliding valves are shifted, in normal situations, the electronic hydraulic braking system (EHB) generates hydraulic pressure through the motor, the pump, the electromagnetic valve and the hydraulic adjusting cylinders, and a traditional mechanical braking system is used underthe situation of system failure; the displacement sensor is mounted on the brake pedal and is used for determining the total braking force; the pressure sensors are mounted on front and back wheel pipelines to ensure real-time control on the hydraulic adjusting module. When normal braking is carried out, the pedal force is fed back by the travel simulators, and a mechanical structure of the braking system is decoupled.

Description

technical field [0001] The invention belongs to the technical field of automobile braking, and in particular relates to a composite braking system of an electric automobile with a wire-controlled braking function. Background technique [0002] At present, the development of electric vehicles that use electricity as a power source is an effective way to alleviate the problems of energy shortage and environmental pollution. A notable feature of electric vehicles is: during the braking process, the kinetic energy of the vehicle is converted into electrical energy by the motor and stored in the battery. and other energy storage devices, and generate braking torque at the same time. However, the braking torque generated by the motor cannot meet the requirements of different braking situations, and the electric braking torque will vary with the vehicle speed and battery SOC. Therefore, generally electric vehicles retain the transmission hydraulic braking system. How to coordinate...

AI Technical Summary

Problems solved by technology

The disadvantages of this system are: 1. The hydraulic pressure is directly from the oil storage tank to the wheel cylinder through the accumulator solenoid valve. There is no buffer pressure adjustment cylinder, which makes the oil pressure change quickly. The corresponding control solenoid valve has a relatively high switching frequency and low control accuracy. ;2. There is no effective failure backup mode, and the solenoid valve is prone to failure under high-speed switching. Once the hydraulic pressure cannot be established, there is a huge hidden danger to driving safety

The disadvantages of this system are: 1. It can only adjust the total hydraulic pressure, and cannot accurately distribute the hydraulic braking force of the front and rear axles, which has a great impact on single-axis drive electric vehicles; 2. There is also the braking safety of electronic control failure. question

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