Electronic-hydraulic compound brake system with electric brake assist function

Abstract

The invention discloses an electronic-hydraulic compound brake system with an electric brake assist function. A brake pedal is trod, a push rod pushes a rack and a brake master cylinder piston, meanwhile, an electronic control unit controls the torque output by a motor according to a signal of a displacement sensor on the pedal, auxiliary force is applied to the master cylinder piston through two sets of transmission pairs, namely a worm-gear pair and a gear-rack pair, and then brake pressure is output to a wheel cylinder. The brake assist system has the advantages that the magnitude of the pedal force is influenced by the difference of the master cylinder pressure and the auxiliary force provided by the motor, and thus the pedal feeling can be designed by adjusting the magnitude of the auxiliary force provided by the motor; the system is convenient for active brake which means that under the condition that the brake pedal is not trod, the brake of all or partial wheels still can be realized; and the torque output by the motor can be controlled by the electronic control unit.

Description

technical field [0001] The invention belongs to the technical field of automobile braking systems, and specifically relates to an electro-hydraulic composite braking system with an electric braking boosting function. Background technique [0002] At present, the hydraulic braking system of automobiles mostly adopts vacuum boosting, but if its working condition is not good, the driver will feel very hard when stepping on the brake pedal, and inexperienced drivers will mistakenly think that there is no braking function. The vacuum environment of the vacuum booster is provided by the engine. The more traditional way is to lead a gas pipe from the intake manifold to the vacuum booster. In order to ensure the stability of the vacuum environment, some engines are also specially designed for the vacuum booster. A mechanical vacuum pump driven by a camshaft was designed. Before that, some manufacturers used electronic vacuum pumps to make up for the "vacuum". [0003] In traditiona...

AI Technical Summary

Problems solved by technology

However, the noise of such an electronic vacuum booster pump is relatively large, and more importantly, the working stability and lifespan of the electronic vacuum pump are not suitable as the main and only vacuum source supply part (originally on traditional cars, it is only auxiliary) maintain a vacuum environment)

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